WO2025008325A1

WO2025008325A1 - Floor frame assembly for modular building unit

Info

Publication number: WO2025008325A1
Application number: PCT/EP2024/068555
Authority: WO
Inventors: Edward Ross SHENTON; David Lee JONES
Original assignee: Sano Development Ltd
Current assignee: Sano Development Ltd
Priority date: 2023-07-05
Filing date: 2024-07-02
Publication date: 2025-01-09
Anticipated expiration: 2026-01-05
Also published as: WO2025008330A1; WO2025008327A1; WO2025008335A1; WO2025008328A1; WO2025008324A1; WO2025008332A1; WO2025008319A1; WO2025008334A1

Abstract

There is disclosed a floor frame assembly for a structural frame of a modular building unit, a structural frame comprising the floor frame assembly, a modular building unit having a structural frame comprising the floor frame assembly, a building comprising the modular building unit, and a method of constructing a building (particularly a hybrid building) comprising a modular building unit. One floor frame assembly disclosed in this document comprises: a floor support portion comprising an upper surface configured to support at least part of a floor structure of the modular building unit; and a perimeter frame comprising a plurality of perimeter frame members, at least some of the perimeter frame members comprising: a base part comprising a lower surface, and an upper surface configured to support a bottom of a side structure of the modular building unit; and a side part disposed transverse to the base part and connected to it, the side part comprising a side surface configured to support a side of the side structure. The upper surface of the base part of each of said perimeter frame members is disposed at a first height above the lower surface. At least a portion of the side part of each of said perimeter frame members extends to a second height above the lower surface of the respective base part which is greater than the first height. The floor support portion is connected to the perimeter frame, and the upper surface of the floor support portion is disposed at a third height above the lower surfaces of said perimeter frame member base parts, the third height being greater than the first height and less than the second height.

Description

FLOOR FRAME ASSEMBLY FOR MODULAR BUILDING UNIT

The present invention relates to a floor frame assembly for a structural frame of a modular building unit, a structural frame comprising the floor frame assembly, a modular building unit having a structural frame comprising the floor frame assembly, a building comprising the modular building unit, and a method of constructing a building (particularly a hybrid building) comprising a modular building unit

Prefabricated buildings (also known as ‘modular’ buildings) are well known in the construction industry, particularly modular residential buildings such as houses, flats or apartments, and hotels. Modular buildings typically comprise a series of building units which are constructed in a factory, transported to a final location (or site) for the building, and then arranged in a predetermined configuration and coupled together to form the finished building. The modular building units are typically constructed to a substantially assembled form in the factory, in which they can be transported to the final location. Construction of the building can involve stacking one or more upper modular building unit on a lower such unit, so that the upper unit is supported by the lower unit.

Hybrid buildings have been developed by the applicant which comprise a first building section that is constructed at a final location for the building, and a second building section comprising one or more modular building unit constructed in a dedicated facility, away from the final location. A hybrid building of this type can provide advantages including that: construction of the first building section is simplified, with more complex parts of the building provided in the section formed by the modular building unit(s); and the first building section can provide the primary living space in the building, without being constrained by construction and transport limitations imposed on the modular building umt(s). The hybrid buildings and associated construction techniques are disclosed in International patent publication nos. WO2022/243696, WO2022/243695, WO2022/243694, WO2022/243693 and WO2023/222853.

Modular building units typically comprise a structural frame having a floor frame assembly, and a side structure (which can form one or more wall) connected to the structural frame. The floor frame assembly defines a base of the modular building unit, and is usually formed from a metallic material (such as a cold or hot-rolled steel), or a timber-based material. The floor frame assembly typically comprises a perimeter frame formed from elongate frame members, and floor joists connected to the perimeter frame The perimeter frame members can be e.g. I-beams or may have a hollow box shape in cross-section (particularly for a metallic frame), or can be of solid e.g. rectangular cross-section (particularly for timber) The side structure is connected to and supported by the perimeter frame, typically by a top surface of its frame members. The floor joists have upper surfaces which support a planar floor structure for the unit. The upper surfaces of the floor joists are typically level with the top surfaces of the perimeter frame members, so that the planar floor structure can pass over the perimeter frame members at doorway or walkway apertures formed at the perimeter of the modular building unit

The floor frame assembly, in particular its perimeter frame, must be capable of supporting relatively high loading. In addition, modular building units forming a lowermost storey or floor of a building are often positioned on a concrete foundation A thick layer of insulation material must therefore be accommodated within the floor frame assembly, in order to reduce thermal energy transfer between the foundation and the modular building unit. As a consequence, the perimeter frame tends to be relatively deep (in a vertical sense), formed for example from beams having a depth of perhaps 30cm (almost 12") or more. It is not possible to reduce the depth of the part of the floor frame assembly which supports the floor structure, due to the requirement to contain the insulation, and also to accommodate the deep perimeter frame beams at the doorway or walkway openings.

Modular building units having deep floor frames can cause problems in hybrid buildings of the type described above, including that matching a floor level of the building section formed from the modular building unit(s) with that formed by the section constructed at the final building location can be challenging In addition, ceiling frames of known modular building units can also be relatively deep Where modular building units are stacked to form a multi-storey building, this can result in a very deep structure at the intersection between the ceiling of a lower unit, and the floor of an upper unit This complicates the transition for a staircase between the units, and also impacts on material usage, weight and costs. It will be understood that these can also be issues in fully modular buildings, including that steps must be taken to accommodate the deep floor during the construction process.

According to a first aspect of the present invention, there is provided a floor frame assembly for a structural frame of a modular building unit, the floor frame assembly comprising: a floor support portion comprising an upper surface configured to support (or define) at least part of a floor structure of the modular building unit; and a perimeter frame comprising a plurality of perimeter frame members, at least some of the perimeter frame members comprising: a base part comprising a lower surface, and an upper surface configured to support a bottom of a side structure of the modular building unit; and a side part disposed transverse to the base part and connected to it, the side part comprising a side surface configured to support a side of the side structure; optionally in which the upper surface of the base part of each of said perimeter frame members is disposed at a first height above the lower surface; optionally in which at least a portion of the side part of each of said perimeter frame members extends to a second height above the lower surface of the respective base part which is greater than the first height; and optionally in which the floor support portion is connected to the perimeter frame, and the upper surface of the floor support portion is disposed at a third height above the lower surfaces of said perimeter frame member base parts, the third height being greater than the first height and less than the second height.

A floor frame assembly having these features may provide numerous advantages.

The upper surface of each perimeter frame member base part supports the bottom of the side structure, whilst the side support surface of its side part supports the side of the side structure. This may provide lateral rigidity to a modular building unit comprising the floor frame assembly: the side part may resist lateral loading that could otherwise cause the side structure to deflect or twist relative to the floor frame assembly. The side part may effectively extend from the base part along/over a portion of said side (in particular a surface of said side), to brace the side structure against such loading.

The arrangement of said perimeter frame base part upper surface, side part and floor support portion surface relative to one another may have the result that an effective depth of the floor support portion (defined between the lower surfaces of the base parts and the upper surface of the floor support portion, and so equivalent to the third height) can be minimised. This is because the side structure is effectively seated below the level of the upper surface of the floor support portion, on the upper surfaces of the base parts (and not on a top surface of a perimeter frame member which is at or above the same height as floor frame member upper surfaces) As a result, the floor support portion may not be required to support the same loads as in prior floor frame assemblies and can have a smaller depth. This can facilitate construction of a building comprising a modular building unit having the floor frame assembly, especially a hybrid residential building of the type described above. In particular, it may facilitate matching a floor level of a building section formed from the modular building unit with a floor level formed by a section constructed at a final building location

The lower surfaces of the base parts of said perimeter frame members may be configured to define at least part of a base of the floor frame assembly, and so of a modular building unit comprising the floor frame assembly The lower surface may be provided lowermost in, on or of the floor frame assembly.

The base part may be provided integrally with the side part. Said perimeter frame members may each be provided as a single or unitary component comprising or defining the base and side parts. All of the perimeter frame members forming the perimeter frame may comprise such base and side parts. However, one or more perimeter frame member may take a different form.

Said perimeter frame members may each comprise or define a channel shaped to receive the side structure. The channel may be formed, described or defined at least partly by the base part and the side part. The side part may be connected to the base part so as to form, describe or define the channel at the intersection between the parts The channel may be open at least at an upper end, for receiving the side structure.

The side part may restrict lateral movement of the side structure relative to the floor frame assembly in at least one direction, which may be a generally horizontal direction (in use), through contact between its side surface and the side of the side structure. The side part may be configured to be connected to the side structure at its side surface. For example, threaded connectors may be used to connect the side part to the side structure, and may pass laterally (e.g. generally horizontally) through the side part and into the side structure. This may provide the benefit that, during handling of the modular building unit (particularly when suspended e.g. from a crane), the threaded connectors are placed under shear loads which are accommodated by shanks of the fasteners. In contrast, prior floor frame assemblies employing such threaded connectors often impart axially directed loads on their fasteners, which are borne by the fastener threads. This can risk stripping of the thread, or tear-out from a mounting aperture, and disconnection of the components Other connection options exist

Depending on the materials chosen, such can include welding and bonding (e.g. using an adhesive).

The side part may be a first side part, and the side surface may be a first side surface. Said perimeter frame members may each comprise a second side part, which may define a second side surface configured to support a further (e g second) side of the side structure The second side part may be disposed transverse to the base part The second side part may be connected to the base part. The second side part may be spaced apart, suitably laterally and/or horizontally, relative to the first side part The base part may extend between and connect the first side part to the second side part. The channel may be formed, described or defined by the base part and the first and second side part. The first side part may form a first side of the channel. The second side part may form a second side of the channel The base part may form a base or bottom of the channel The first and second side surfaces, and the upper support surface (of the base part) may face, and/or define boundaries of, the channel. The first and second side parts may be configured to capture the side structure between them, so as to restrict lateral movement of the side structure relative to the floor frame assembly. The second side part may extend to the second height, or to another height above the lower support surface of the base part which is different (e g less than) the second height

Said perimeter frame members may be generally U-shaped, generally C-shaped, or generally L-shaped, in crosssection.

The side part of each of said perimeter frame members may be disposed generally perpendicular to the respective base part. The upper support surface of each base part may be disposed generally horizontally (in use). The side surface may be disposed generally vertically (in use). Where there are first and second side surfaces, the side surfaces may be disposed: generally vertically (in use); and/or generally parallel to one another.

The floor frame assembly may comprise one or more doorway or walkway area, which may define a location for a doorway or walkway in the modular building unit. One or more portion of one or more of the side parts may have/may extend to a height which is less than the second height, and which may be less than or equal to the third height. Said one or more portion may define the doorway or walkway area. An aperture may be provided/ formed in the one or more side part which defines the doorway or walkway area. The aperture may be formed by cutting away or removing a section of said side part, or by folding a section of said side part.

The base parts of said perimeter frame members may extend continuously between their lower and upper surfaces. The first height may represent a depth of the base part. Suitable materials for forming the perimeter frame include metallic materials (e.g. metals and metal alloys, particularly steel), which can be hot or cold- formed. The first height (and so the depth of the base parts) may be in the range of about 3mm (~0.118") to about 5mm (~0. 197"). The second height may be at least around 200mm (~7.874”). The second height may be up to around 600mm (-23.622"). The second height may be up to around 400mm (-15.748") The second height may be in a range of about 200mm to about 400mm. Providing the side parts of said perimeter frame members with a second height in this range may provide effective support for the side structure without adding significant bulk or weight to the floor frame assembly . F actors impacting on the second height may include a thickness of material forming the side part

The third height may be up to about 70mm (-2.756"). This may provide the floor support portion with an effective depth which is relatively shallow, and which may be significantly shallower than in conventional modular building units. In a hybrid building comprising a first section constructed at a final location, and a second section comprising the modular building unit, a level of a floor of the first section may be brought up to that of the second section by applying e.g. a cementitious screed to a floor support structure of the first section It may be preferred to restrict the third height to no more than around 70mm, which may be a maximum optimal height for such a screed. The third height may be up to around 50mm (-1.968"). The third height may be in a range of about 50mm to about 70mm. A third height in the region of around 50mm may be preferred.

The floor support portion may comprise a plurality of floor frame members which together form the portion The floor frame members may each have an upper surface, and may together form the upper surface configured to support the floor structure. Each floor frame member upper surface may be configured to support a part of the floor structure. The floor support portion may comprise, or may be defined by, a single or unitary structure which forms the upper surface. Options include a slab or plate, which may for example be of a cementitious material. At least part of the floor support portion may comprise an upper surface which is at a fourth height above the lower surfaces of said perimeter frame member base parts. The fourth height may be different to the third height, and may for example be less than the third height. Another and more preferred option however may be to provide a part of the floor structure with a reduced depth, or to arrange the floor structure so that it does not extend over a part of the floor support portion. Either option may provide e.g. a depression or recessed area which may be configured to receive a pod having an integral floor (the pod e.g. containing a wet facility such as a bathroom, W/C or washroom, utility room or ensuite). In this way, it may be possible to match a level of said integral floor with a floor of the modular building unit

Reference is made to first, second and third heights of features of the floor frame assembly. It will be understood that these and other heights referred to herein should be taken in a generally vertical sense, and in normal use of a modular building unit comprising the floor frame assembly. The heights are all taken with reference to the lower surfaces of the base parts, which should be understood to be generally in a same plane, and so providing a common reference point The features whose heights are referred to should not necessarily be taken to be positioned vertically above said lower surfaces, and so could be displaced e g. laterally relative to one or more of said lower surfaces.

According to a second aspect of the present invention, there is provided a structural frame comprising the floor frame assembly of the first aspect. The structural frame may comprise a ceiling frame assembly, and the side structure, the side structure extending between and connecting the floor frame assembly to the ceiling frame assembly.

Further features of the floor frame assembly of the second aspect may be derived from the text set out elsewhere in this document, particularly in or with reference to the first aspect of the invention

According to a third aspect of the present invention, there is provided a modular building unit comprising a structural frame and a floor structure, the structural frame comprising a floor frame assembly, a ceiling frame assembly, and a side structure extending between and connecting the floor frame assembly to the ceiling frame assembly, in which the floor frame assembly comprises: a floor support portion comprising an upper surface configured to support (or define) at least part of the floor structure; and a perimeter frame comprising a plurality of perimeter frame members, at least some of the perimeter frame members comprising: a base part comprising a lower surface, and an upper surface configured to support a bottom of the side structure; and a side part disposed transverse to the base part and connected to it, the side part comprising a side surface configured to support a side of the side structure; optionally in which the upper surface of the base part of each of said perimeter frame members is disposed at a first height above the lower surface; optionally in which at least a portion of the side part of each of said perimeter frame members extends to a second height above the lower surface of the respective base part which is greater than the first height; and optionally in which the floor support portion is connected to the perimeter frame, and the upper surface of the floor support portion is disposed at a third height above the lower surfaces of said perimeter frame member base parts, the third height being greater than the first height and less than the second height

Optional further features of the structural frame of the second aspect, and/or the modular building unit of the third aspect, are as follows.

The side structure may form one or more wall of the modular building unit. The one or more wall may be an external wall (of the unit). The one or more wall may be provided at a perimeter of the unit, and/or may define at least part of a perimeter of the unit. The side structure may comprise support posts or columns, which may be provided at one or more corner of the modular building unit, in particular at one or more comer of the floor frame assembly. At least one support post/column may be provided at a location on a perimeter of the floor frame assembly which is spaced from one or more of the comers. The side structure may comprise one or more wall panel, which may be coupled to a support post or posts to form a wall, or part of a wall. The support posts or columns may have a lower end which may form part of the bottom of the side structure. The support posts or columns may have a side which may form part of the side of the side structure The one or more wall panel may have a lower end which may form part of the bottom of the side structure. The one or more wall panel may have a side which may form part of the side of the side structure Other options for the side structure exist, including structural insulated panels (SIPs), and other panels e.g. of a cement-based material Such panels may form at least part of the bottom of the side structure, and at least part of the side. Where the side structure comprises or is defined by a panel, the panel may comprise top and bottom frame members, and columns or posts extending between and connecting said frame members. The top and bottom frame members may be of a first material and the columns or posts of a second material which is different to the first material The first material may be the same as a material of the floor and ceiling frame assemblies, e.g. where said frame assemblies are of a metallic material then the top and bottom frame members of the panel may also be of that metallic material. The second material may be a timber or timber-based material.

The ceiling frame assembly may comprise a ceiling support portion comprising a plurality of ceiling frame members having lower surfaces configured to support a ceiling structure. The ceiling frame assembly may comprise a perimeter frame comprising a plurality of perimeter frame members, at least some of the perimeter frame members comprising: a top part comprising an upper surface, and a lower surface configured to support a top of the side structure; and a side part disposed transverse to the top part and connected to it, the side part comprising a side surface configured to support a side of the side structure The ceiling support portion may be connected to the ceiling perimeter frame.

The ceiling frame assembly may comprise at least one mounting/spacing member, and may comprise a plurality of mountmg/spacmg members. Said mounting member may serve for mounting a further (e.g. upper) modular building unit on the modular building unit. Said mounting member may protrude or extend from an upper surface or extent of a ceiling perimeter frame member or members. Said mounting member may extend upwardly and/or m a generally vertical direction, optionally away from the upper surface/extent of the ceiling frame perimeter member(s). The at least one mounting member may take the form of a block, post, stub, pin or P^eg-

One or more ceiling frame perimeter member may be arranged to define at least one mount. Said mount may serve for mounting a further (e.g. upper) modular building unit on the modular building unit. Said ceiling frame perimeter member may comprise an upper surface or extent, and at least one mount may extend from the upper surface or extent. Said mount may extend upwardly and/or in a generally vertical direction, optionally away from the upper surface/extent of the ceiling frame perimeter member(s).

One or more aperture may be formed between adjacent mounting members/mounts, which may provide a pathway for utilities/building services equipment (such as sewerage, ventilation, power and/or communication conduits).

The at least one mounting/spacing member, in particular an upper surface of said mounting member, may be configured to contact a lower surface of a further (e.g. upper) modular building unit stacked or seated on the modular building unit, in particular a lower surface of a floor frame assembly of said further unit. This may provide the advantage that a void, space or gap can be formed between the two modular building units using the at least one mounting member, which may accommodate e g utilities/building services equipment such as sewerage, ventilation, power and/or communication conduits. Said void can be created with minimal additional structure, and so cost and weight savings. The at least one mounting member may be coupled to, or provided by (e g. integral to), the ceiling frame assembly. There may be a plurality of mounting members, which may be spaced apart around a perimeter of the modular building unit defined by the ceiling frame assembly. A mounting member may be provided at each comer of the modular building unit, which comers may be defined by the ceiling frame assembly.

The floor support portion may have or define a first depth. The ceiling support portion may have or define a second depth, which may be different to (particularly greater than) the first depth. A ratio of the first depth of the floor support portion relative to the second depth of the ceiling support portion may be at least about 1 :3 The second depth may be defined between the upper surfaces of the top parts of the perimeter frame members, and the lower surfaces of the ceiling frame members of the ceiling support portion. The ratio of the first depth relative to the second depth may be up to about 1 :6. The ratio of the first depth relative to the second depth may be in a range of between about 1 :3 to about 1 :6. A ratio falling within this range may provide a good balance of a relatively thin floor frame assembly, and a ceiling frame assembly that can provide a majority of the structural strength for the modular building unit and/or space to accommodate e.g. utilities/building services equipment

The second depth of the ceiling frame assembly may be at least about 150mm (-5.906"). The second depth may be up to about 300mm (~11.811 ") The second depth may be in a range of about 150mm to about 300mm. A depth in the region of about 250mm may be preferred.

A modular building unit having such floor and ceiling frame assembly first and second depths may provide a good balance of benefits, e.g. in terms of minimising disruption to accommodate the floor frame assembly and/or minimising a depth of structure at a transition between lower and upper modular building units, whilst providing a sufficiently strong ceiling frame assembly and/or depth in the ceiling frame assembly to accommodate utilities/building services equipment

The modular building unit may be generally quadrilateral-shape in plan view, may be generally rectangular, and may be generally cuboid

The floor structure may be generally planar. The floor structure may define a floor of the modular building unit. The floor structure may comprise, or may be defined by, one or more planar floor panel The first depth of the floor support portion may not include said floor structure, other structural or insulative material positioned on said floor structure, and/or any decorative floor finish or covering (e.g. carpet or tiles) positioned on said floor structure.

The ceiling frame assembly, m particular its ceiling support portion, may be configured to support a ceiling structure. The ceiling structure may be generally planar. The ceiling structure may define a ceiling of the modular building unit. The ceiling structure may comprise, or may be defined by, one or more planar ceiling panel The second depth of the ceiling frame assembly may not include the ceiling structure, other structural or insulative material connected to the ceiling structure, and/or any decorative finish or covering (such as a cementitious coating) applied to the ceiling structure.

Reference is made in this document to a ceiling frame assembly of the modular building unit, and to a ceiling of the unit Reference to a ceiling frame assembly (and a ceiling) should be taken to mean an upper structure which covers or encloses an internal volume of the modular building unit. It will be understood that the ceiling frame assembly of the modular building unit will not typically provide a weather-resistant roof structure intended to prevent e g. water ingress into the modular building unit. For example, a roof structure may be formed separately and positioned above the modular building unit in order to weatherproof it. However, the modular building unit could optionally provide such a roof, for example by arranging the ceiling frame assembly to additionally provide or define an external or outer roof for the unit. This may be an option particularly e.g. for single storey buildings comprising the modular building unit, or where the unit forms an uppermost storey of a building. Suitable options can include a flat roof structure.

The modular building unit may define a circulation space configured to provide at least one access function for a building comprising the modular building unit. The access function provided by the circulation space (which may also be referred to as a circulation zone or transition space/zone) may be selected from the group comprising: access between upper and lower living spaces of the building (e.g provided by upper and lower storeys of the building), optionally via a staircase or a lift shaft and lift, provided at least partly in the modular building unit; access between a first living space and at least one further living space of the building, said living spaces optionally being isolated from one another within another part of the building and optionally on a same level/storey (e.g. via a hallway /landing and one or more doorway or walkway provided at least partly in the modular building unit); and access into the building from an exterior of the building (e g. via one or more doorway or walkway, and optionally also a hallway, provided by the modular building unit). The circulation space may be defined wholly by the modular building unit. For example, where the circulation space provides access from the outside of the building, the space may be defined wholly by a single such unit. The circulation space may be defined in combination by a plurality of modular building units. For example, where the circulation space provides access between upper and lower living spaces, two or more units may cooperate to define the access, e.g. each may form part of a staircase or lift shaft.

The modular building unit may define (and suitably may completely or entirely define) at least one room, and may define a plurality of rooms. The modular building unit may comprise an internal volume, and the room(s) may be defined within, and may accommodate part of, said volume. The modular building unit may be arranged so that it comprises one or more wall, which may define a boundary or boundaries (optionally all boundaries) of said room. At least one room may contain a wet facility, which may be selected from the group comprising a bathroom, a shower room, an ensuite, a W/C or washroom, and a utility room. One or more further room of the plurality of rooms may be arranged to contain a wet facility. The modular building unit may be arranged to define at least part of a perimeter of the building, which may be an external perimeter. The side structure may define or comprise one or more wall, and a wall or walls of the modular building unit may be arranged to define said part of the perimeter. The wall or walls may be arranged so that an external surface of the wall or walls defines an external surface of the building, or may be clad or surfaced with an exterior surface finish/coating (e.g. panels, bricks slips, cementitious render)

Further features of the floor frame assembly forming part of the structural frame of the third aspect may be derived from the text set out elsewhere in this document, particularly in or with reference to the first aspect of the invention.

According to a fourth aspect of the present invention, there is provided a building comprising the modular building unit of the third aspect.

The building may be a hybrid building, in particular a hybrid residential building comprising a first building section and a second building section. The first building section may be an on-site construction at a final location for the building The second building section may be defined by and/or may comprise the modular building unit. The first and second building sections may be configured to be connected at the final location to form the building The building may comprise a plurality of modular building units, at least one of which may be a modular building unit according to the third aspect

The building may be a modular building comprising a plurality of modular building units (at least one of which is the modular building unit according to the third aspect). An internal volume of the building, optionally excepting an upper or outer roof of the building, may be formed entirely by said units.

The building may comprise a foundation comprising a load bearing structure and thermal insulation. The modular building unit may be located on the foundation so that the load bearing structure provides structural support for the modular building unit, and so that the thermal insulation thermally insulates the modular building unit relative to the ground.

The modular building unit may have any of the further features set out above in relation to the third aspect.

According to a fifth aspect of the present invention, there is provided a method of constructing a hybrid building comprising the steps of: constructing a first building section at a final location for the building; at a location away from the final location, constructing a modular building unit according to the third aspect of the invention to a substantially assembled form; transporting the modular building unit to the final location in the substantially assembled form, and arranging the modular building unit to form at least part of a second building section of the building; and connecting the first and second building sections to form the building. The building may be a hybrid residential building

The method may comprise constructing a foundation for the building, which may comprise providing the foundation with a load bearing structure and thermal insulation. The method may compnse locating the modular building unit on the foundation so that the load bearing structure of the foundation provides structural support for the modular building unit, and so that the thermal insulation of the foundation thermally insulates the modular building unit relative to the ground. The method may comprise arranging the first building section so that it is supported by the foundation.

The method may comprise arranging the modular building unit so that its floor structure comprises an upper surface The method may comprise providing the first building section with a floor, and may comprise providing the floor with an upper surface. The method may comprise arranging the floor of the first building section so that its upper surface is at a common or uniform height with the upper surface of the modular building unit floor structure.

Further features of the method may be derived from the text set out elsewhere in this document, particularly in or with reference to any one or more of the first to fourth aspects.

Reference is also made to the hybrid building and associated construction methods disclosed in International patent publication nos WO2022/243696, WO2022/243695, WO2022/243694, WO2022/243693 and WO2023/222853, the disclosures of which are incorporated herein by this reference.

In a further aspect of the mvention, there is provided a ceiling frame assembly for a structural frame of a modular building unit having any of the features set out in this document, particularly in or with reference to the aspects of the invention set out above.

According to a sixth aspect of the present invention, there is provided a ceiling frame assembly for a structural frame of a modular building unit, the ceiling frame assembly comprising: a ceiling support portion comprising a lower surface configured to support (or define) at least part of a ceiling structure of the modular building unit; and a perimeter frame comprising a plurality of perimeter frame members, at least some of the perimeter frame members comprising: a top part comprismg an upper surface, and a lower surface configured to support a top of a side structure of the modular building unit; and a side part disposed transverse to the top part and connected to it, the side part comprising a side surface configured to support a side of the side structure; in which the lower surface of the top part of each of said perimeter frame members is disposed a first distance below the upper surface; in which at least a portion of the side part of each of said perimeter frame members extends to a second distance below the upper surface of the respective top part which is greater than the first distance; and in which the ceiling support portion is connected to the perimeter frame, and the lower surface of the ceiling support portion is disposed a third distance below the upper surfaces of said perimeter frame member top parts, the third distance being greater than the first distance and less than the second distance.

The ceiling frame assembly may comprise a ceiling support portion comprising a plurality of ceiling frame members having lower surfaces configured to support a ceiling structure.

The ceiling frame assembly may comprise at least one mounting/spacing member, and may comprise a plurality of mountmg/spacmg members. Said mounting member may serve for mounting a further (e.g. upper) modular building unit on the modular building unit Said mounting member may protrude or extend from an upper surface (or extent) of a ceiling perimeter frame member or members. Said mounting member may extend upwardly and/or in a generally vertical direction, optionally away from the upper surface/extent of the ceiling frame perimeter member(s). The at least one mounting member may take the form of a block, post, stub, pin or P^eg-

According to a seventh aspect of the present invention, there is provided a structural frame comprising the ceiling frame assembly of the sixth aspect.

According to an eighth aspect of the present invention, there is provided a modular building unit comprising the structural frame of the seventh aspect and a ceiling structure.

According to a ninth aspect of the present invention, there is provided a building comprising the modular building unit of the eighth aspect

According to a tenth aspect of the present invention, there is provided a method of constructing a hybrid building comprising the steps of: constructing a first building section at a final location for the building; at a location away from the final location, constructing a modular building unit according to the eighth aspect of the invention to a substantially assembled form; transporting the modular building unit to the final location in the substantially assembled form, and arranging the modular building unit to form at least part of a second building section of the building; and connecting the first and second building sections to form the building. Further features of the ceiling frame assembly, structural frame, modular building unit, building and method of the sixth to tenth aspects may be derived from the text set out elsewhere in this document, including in or with reference to any one or more of the first to fifth aspects.

According to an eleventh aspect of the present invention, there is provided a floor frame assembly for a structural frame of a modular building unit, the floor frame assembly comprising: a floor support portion comprising an upper surface configured to support (or define) at least part of a floor structure of the modular building unit; and a perimeter frame comprising a plurality of perimeter frame members, at least some of the perimeter frame members having a generally L-shaped or generally U-shaped structure comprising: a base part configured to support a bottom of a side structure of the modular building unit; and a side part disposed transverse to the base part and connected to it, the side part comprising a side surface configured to support a side of the side structure; in which the floor support portion is connected to the perimeter frame, and optionally in which the upper surface of the floor support portion is disposed above the base parts of said perimeter frame members; and optionally in which at least a portion of the side part of each of said perimeter frame members extends above the upper surface of the floor support portion.

The base part and the side part may together define a channel configured to receive the side structure The side part may be a first side part, and the side surface may be a first side surface. Said perimeter frame members may each comprise a second side part, which may define a second side surface configured to support a further (e g. second) side of the side structure. The second side part may be disposed transverse to the base part. The second side part may be connected to the base part. The second side part may be spaced apart, suitably laterally and/or horizontally, relative to the first side part. The base part may extend between and connect the first side part to the second side part. The channel may be formed, described or defined by the base part and the first and second side part. The first side part may form a first side of the channel. The second side part may form a second side of the channel. The base part may form a base or bottom of the channel The first and second side parts may be configured to capture the side structure between them, so as to restrict lateral movement of the side structure relative to the floor frame assembly.

Further features of the floor frame assembly may be derived from the text set out elsewhere in this document, including in or with reference to any one or more of the first to fifth aspects.

In further aspects of the present invention, there may be provided: a structural frame comprising the floor frame assembly of the eleventh aspect, a modular building unit comprising the structural frame, a building comprising the modular building unit, and/or a method of constructing a hybrid building comprising the modular building unit.

According to a twelfth aspect of the present invention, there is provided a ceiling frame assembly for a structural frame of a modular building unit, the ceiling frame assembly comprising: a ceiling support portion comprising a lower surface configured to support (or define) at least part of a ceiling structure of the modular building unit; and a perimeter frame comprising a plurality of perimeter frame members, at least some of the perimeter frame members having a generally inverted L-shaped or generally inverted U-shaped structure comprising: a top part configured to support a top of a side structure of the modular building unit; and a side part disposed transverse to the top part and connected to it, the side part configured to support a side of the side structure; in which the ceiling support portion is connected to the perimeter frame, and optionally in which the lower surface of the ceiling support portion is disposed below the top parts of said perimeter frame members; and optionally in which at least a portion of the side part of each of said perimeter frame members extends below the lower surface of the ceiling support portion

Further features of the ceiling frame assembly may be derived from the text set out elsewhere in this document, including in or with reference to any one or more of the first to fifth aspects.

In further aspects of the present invention, there may be provided: a structural frame comprising the ceiling frame assembly of the twelfth aspect, a modular building unit comprising the structural frame, a building comprising the modular building unit, and/or a method of constructing a hybrid building comprising the modular building unit.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Fig. 1 is an isometric view of a modular building unit, comprising a floor frame assembly, according to an embodiment of the invention;

Fig. 2 is a view of the modular building unit which is similar to Fig. 1 , but with parts of a side structure of the modular building unit removed, for illustration purposes;

Fig. 3 is an isometric view of a modular building assembly comprising the modular building unit shown in Fig. 1, and a further modular building unit;

Fig. 4 is an enlarged isometric view of the modular building unit shown in Fig. 2, showing the floor frame assembly in more detail;

Fig. 5 is a further enlarged isometric view of the floor frame assembly shown in Fig. 2, with the side structure of the unit removed;

Fig. 6 is a yet further enlarged end view of the floor frame assembly, taken in the direction of the arrow A in Fig. 4; Figs 7 and 8 are front and side views respectively of a hybrid building according to an embodiment of the invention, comprising the modular building assembly of Fig. 3, and drawn to a smaller scale;

Fig. 9 is a view of the building corresponding to Fig. 4, sectioned in a vertical plane along the line B-B in Fig. 8;

Figs 10 and 11 are plan views of lower and upper storeys respectively of the hybrid building shown in Figs. 7 to 9, drawn to a larger scale;

Fig. 12 is a vertical cross-sectional view of part of a foundation for the building, and of the modular building unit shown in Fig 1;

Fig. 13 is enlarged end view of a ceiling frame assembly of the modular building unit, taken in the direction of the arrow A in Fig. 4;

Fig 14 is a wire -frame isometric view of a plurality of modular building assemblies, configured to form part of a building according to an alternative embodiment of the invention; and

Figs 15 and 16 are views corresponding to Fig. 13 but showing ceiling frame assemblies of modular building units according to further embodiments of the invention.

Turning firstly to Fig. 1, there is shown an isometric view of a modular building unit according to an embodiment of the invention, the unit illustrated generally by reference numeral 10. The modular building unit 10 is also shown in Fig. 2, which is a view corresponding to Fig 1 but with parts of a side structure of the modular building unit removed, so that a structure of the unit can be better seen. Fig. 3 is also referred to, which is an isometric view of a modular building assembly comprising the modular building unit shown in Fig. 1. The modular building assembly is indicated generally by reference numeral 12, and comprises the modular building unit 10, and a further modular building unit, which is indicated by numeral 14.

The modular building unit 10 comprises a structural frame, indicated generally by numeral 16. The structural frame 16 comprises a floor frame assembly 18 configured to support at least part of a planar floor structure (which will be described below). The structural frame additionally comprises a ceiling frame assembly 20, and a side structure 22 extending between and connecting the floor frame assembly 18 to the ceiling frame assembly.

The floor frame assembly 18 is shown more clearly in the enlarged isometric view of Fig. 4, which is based on Fig. 2. The floor frame assembly 18 generally comprises a floor support portion 24, and a perimeter frame 26. The floor support portion 24 comprises an upper surface 28 configured to support at least part of a floor structure of the modular building unit 10, part of the floor structure shown separately in Fig. 4 and indicated by numeral 30. The perimeter frame 26 comprises a plurality of penmeter frame members which together form the frame These comprise first and second side frame members 32 and 34, and first and second end frame members 36 and 38 (which are not shown in Fig 2, but can be seen in Fig. 1). The first and second side frame members 32 and 34 respectively form left and right side frame members The first and second end frame members 36 and 38 respectively form front and back frame members. These frame members 32 to 38 typically have the same general structure (which will be described below), although one or more of the frame members may have a different structure

The structure of the perimeter frame members 32 to 38 will now be described, with reference also to Fig 5, which is an enlarged view of the floor frame assembly 18 shown in Fig. 4, and Fig. 6, which is an enlarged end view taken in the direction of the arrow A in Fig 4. Reference will be made to the second side frame member 34, although it will be understood that the description of its features also applies to the other frame members 32, 36 and 38.

As can be seen, the second side member 34 comprises a base part 40 comprising a lower surface 42, and an upper surface 44 which is configured to support a bottom 46 of the side structure 22. The second side member 34 also comprises a side part 48 disposed transverse to the base part 40 and connected to it, the side part comprising a side surface 50 configured to support a side 52 of the side structure 22. The upper surface 44 of the base part 40 is disposed at a first height Hi above its lower surface 42, and at least a portion 54 (Fig 5) of the side part 48 extends to a second height H2 above the lower surface. As can be seen, the second height H2 is greater than the first height Hi . The floor support portion 24 is connected to the perimeter frame 26, and the upper surface 28 of the floor support portion is disposed at a third height H3 above the lower surface 42 of the base part 40 (and so the lower surfaces of base parts of the other perimeter frame members 32, 36 and 38, which rt wrll be understood are at a common herght/rn a common plane to the base part 40 lower surface 42). The thrrd height H3 is greater than the first height Hi, and less than the second height H2.

A floor frame assembly having these features may provide numerous advantages. The upper surface 44 of the base part 40 supports the bottom 46 of the side structure 22, whilst the side support surface 50 of its side part 48 supports the side 52 of the side structure. This provides lateral rigidity to the modular building unit 10, the side part 48 resisting lateral loading that could otherwise cause the side structure 22 to deflect or twist relative to the floor frame assembly 18. As can be seen particularly in Fig. 6, the side part 48 effectively extends from the base part 40 along or over a portion of the side 52 of the side structure 22 (in particular a surface of said side), to brace the side structure against such loading.

The arrangement of the base part upper surface 44, side part 48 and floor support portion surface 28 at these heights Hi, H2 and H3 relative to the lower surface 42 has the result that an effective depth Di of the floor support portion 24 (defined between the lower surface 42 of the base part 40 and the upper surface 28 of the floor support portion, and so equivalent to the third height H3) can be minimised. This is because the side structure 22 is effectively seated below the level H3 of the upper surface 28 of the floor support portion 24, on the upper surface 44 of the base part 40 (and not on a top surface of a perimeter frame member which is at or above the same height as floor frame member upper surfaces, as in prior modular building units). As will be described below, the lower surface 42 of the base part 40 rests on a prepared foundation, and so directly supports the side structure 22 on the foundation. As a result of this, the floor support portion 24 may not be required to support the same loads as in prior floor frame assemblies, and can have a smaller depth. This can facilitate construction of a building comprising the modular building unit 10, especially a hybrid (e.g residential) building of a type that will be described below. In particular, it may facilitate matching a floor level of a building section formed from the modular building unit 10 with a floor level formed by a section constructed at a final building location.

Numerous options for forming the structural frame 16 exist. Preferred options include a metallic frame, which can be of a cold-formed metal or metal alloy (e g. light gauge steel), a hot formed metal or metal alloy (e.g hot rolled steel), or combinations of the two A hot-formed metallic frame may provide a sufficiently rigid structure so that support posts and bracing struts can be dispensed with (or the number of posts/struts reduced). Other options could include timber-based frames. In the illustrated embodiment however, the structural frame 16 is formed from cold-formed steel. Connection methods for structural components of the frame can include welding (metallic frames), bonding and mechanical fixations such as nut and bolt assemblies and rivets, and screws (particularly self-tapping screws, often referred to as ‘tek screws’)

Figs 7 and 8 will now be referred to, which are front and side views of a hybrid building 56 according to an embodiment of the invention, comprising the modular building unit 10, and the modular building assembly 12, of Figs. 1 and 3. The hybrid building 56 is also shown in Fig. 9, sectioned in a vertical plane along the line B-B in Fig. 8. In the illustrated embodiment, the hybrid building 56 is a residential building in the form of a house, and in particular a detached house The principles of the invention can however apply to other types of house, including semi-detached and terraced, as well as single storey houses (bungalows). In addition, the principles of the invention can apply to other residential buildings such as flats/apartments and hotels, and indeed to non- residential buildings, e.g industrial or commercial buildings

The hybrid building 56 comprises a first building section 58 and a second building section 60. The first building section 58 is an on-site construction at a final location 62 for the building 56, and is generally L-shaped m plan view (although not restricted to that shape). This can be seen particularly in Figs. 10 and 11, which are plan views of lower 63 and upper 65 storeys respectively of the hybrid building 56, drawn to a larger scale. The second building section 60 comprises the modular building unit 10, which is generally rectangular shape in plan view. The unit 10 is constructed to a substantially assembled form away from the final location 62, for example in a dedicated factory or facility. The unit 10 is transported to the final location 62 in its substantially assembled form, and arranged to form at least part of the second building section 60. In the illustrated embodiment, the second building section 60 is effectively formed by the modular building assembly 12, and so comprises both the modular building unit 10, and the further modular building unit 14. The further unit 14 is preferably a unit according to the invention, and so has similar features to the unit 10, which share the same reference numerals with the addition of the suffix'. As explained in detail in International patent publication nos. WO2022/243696, WO2022/243695, WO2022/243694, WO2022/243693 and WO2023/222853, the hybrid building 56 is formed by connecting the first and second building sections 58 and 60 together at the final location 62. As can be seen from the drawings, the second building section 60 fits with the generally L-shaped first building section 58 in order to form a building having a generally rectangular shape in plan view Other shapes are of course possible. The modular building unit 10 can have any suitable dimensions, with the proviso that it will generally be required to be transported e.g. by road or rail from the factory to the final location 40. The illustrated unit 10 is around 5300 to 5400mm in length, and around 2500 to 2600mm in width, which is particularly suited to such transportation. The unit 10 is smaller than many conventional modular building units, which can facilitate transportation and handling. This can also facilitate provision of the relatively thin floor described herein, and provides material, weight and cost savings. Although the illustrated unit 10 extends only part way between the front and back of the building 56, other units according to the invention may extend the full length of the building, and so may e g have a greater length dimension

The modular building units 10 and 14 define a circulation space configured to provide one or more access function for the hybrid building 56. This is best shown in Figs 10 and 11, the circulation space indicated by numeral 64, and shown in broken outline and cross-hatched in the drawings. In the illustrated embodiment, the circulation space 64 provides three access functions

One such function is access between lower 66 and upper 68 living spaces of the building 56, provided respectively by the lower and upper storeys 63, 65. This is achieved by means of a staircase 70 in the modular building unit 10 (but could be achieved e.g. via a lift shaft and lift). The living space 66 forms a lounge or sitting room, whilst the living space 68 forms a main or master bedroom, and the circulation space 64 therefore provides access between these different living spaces

Another such function is access between a first living space and at least one further living space of the building 56, the living spaces being isolated from one another within another part of the building (in this case the first building section 58). This is illustrated in Fig. 11, in relation to the further modular building unit 14. The first building section 58 comprises the living space 68 (master bedroom), and a further living space 72, which forms a second bedroom. The circulation space 64 provides access between these living spaces 68 and 72, by means of walkway openings 74, 76 and a landing 78. It will be noted here that the precise configuration of walkway openings shown in Figs. 10 and 11 are slightly different to those shown in the drawing Figs. 1 to 3, of the units 10 and 14. This illustrates alternative possible positions for the walkway openings. This applies particularly to the unit 10, which in Fig 1 comprises internal walkway openings 80 and 82, whereas Fig. 10 shows an open plan area 84 of the unit 10, which effectively forms part of the living space 66 in the completed building 56.

The circulation space 64 additionally provides access between the lower living space 66 and the upper living space 68, which are effectively isolated from one another within the first building section 58 The circulation space 64 can also, in some configurations, provide access between the lower living space 66 and a further living space 86 in the lower storey 63 (forming a kitchen/dmer), which may be isolated from one another within the first building section 58, and accessed via the unit 10 (when it has the configuration of walkway openings 80 and 82 of Fig. 1). Also, in addition to providing access between the further living spaces 68 and 72 (bedrooms), access to/from a further living space 88 (providing a third bedroom) is also provided in the upper storey 65 The circulation space 64 provides access both between these bedroom living spaces 68, 72 and 88, and between the lower living spaces 66/86 and these bedroom living spaces.

Another such function is access into the building 56 from an exterior 90 of the building, via a doorway or walkway 92 of the unit 10, which in this case forms a front doorway for the building 56 The doorway 92 opens on to a hallway 94 to provide access to the staircase 70 (for access to upper living spaces 68, 72 and 88), and the internal walkways 80 and 82 (for access to the lower living spaces 66 and 86, where the unit 10 is configured as in Fig. 1).

Whilst the illustrated modular building assembly 12 comprises modular building units 10 and 14 comprising a circulation space 64 which provides all three access functions described above, it will be understood that variations may provide only one or only some of the stated functions.

The floor frame assembly 18 will now be described in more detail. Referring again to Figs. 4 to 6, the lower surface 42 of the base part 40 of the perimeter frame member 34 defines part of a base of the floor frame assembly 18, and so of the modular building unit 10. In the illustrated embodiment, each of the left side, front end 36 and rear end 38 perimeter frame members similarly comprise a base part having a lower surface Referring for example to the left side frame member 32 shown in Fig. 4, said frame member comprises a base part 40a and a side part 48a. Like components of the base and side parts 40a, 48a with the base and side parts 40, 48 share the same reference numerals, with the addition of the suffix ‘a’

As shown, the base part 40a comprises a lower surface 42a and an upper surface 44a. The lower surface 42a, together with the lower surface 42 of the base part 40, and the lower surfaces of base parts of the front and back end frame members 36 and 38, define the base of the unit 10. These lower surfaces are provided lowermost on the floor frame assembly 18 and rest on the foundation, as mentioned above. The upper surface 44a similarly supports a bottom of the side structure 22, as do the upper surfaces of the further base parts. The base part 40 is provided integrally with the side part 48. Effectively, the perimeter frame members 32-38 are each provided as a single or unitary component comprising or defining the base and side parts (thus the right side frame member 34 comprises both the base part 40 and the side part 48).

The perimeter frame members 32-38 each comprise or define a channel shaped to receive the side structure.

This can be seen particularly in Fig 6, in relation to the right side frame member 34, which comprises a channel 96 defined by the base part 40 and the side part 48. As can be seen, the channel 96 is open at an upper end, for receiving the side structure 22.

The side part 48 restricts lateral movement of the side structure 22 relative to the floor frame assembly 18 in at least one direction, which is a generally horizontal direction (in use). This is achieved through contact between the side surface 50 of the side part 48 and the side 52 of the side structure 22. The side part 48 is connected to the side structure 22 at its side surface 52 A number of options exist including welding, bonding and mechanical connectors In the illustrated embodiment, self-tapping screws (known as ‘tek screws’) are used to achieve connection, as indicated generally at 98 in the drawing. Other mechanical connectors can include rivets or nut and bolt assemblies. The screws 98 pass laterally (generally horizontally) through the side part 48 and into the side structure 22. This provides the benefit that, during handling of the modular building unit 10 (particularly when suspended e.g. from a crane), the threaded connectors 98 are placed under shear loads which are accommodated by shanks 100 of the fasteners The side part 48, by extending to the height H2, provides support to the side structure 22 to resist lateral movement in the direction of the arrow C in Fig 6 Connection of the side part 48 to the side structure 22 additionally serves to resist lateral movement in the direction of the arrow D.

The side part 48 effectively forms a first side part of the frame member 34, and the side surface 50 forms a first side surface. The perimeter frame member 34 (and indeed the remaining perimeter frame members 32, 36 and 38) comprises a second side part 102, which defines a second side surface 104 configured to support a second side 106 of the side structure 22. The second side part 102 is disposed transverse to the base part 40 and again connected to the base part. The second side part 102 is spaced apart laterally and/or horizontally relative to the first side part 48, the base part 40 extending between and connecting the first side part to the second side part The channel 96 is defined by the base part 40 and the first and second side parts 48, 102. The first side part 48 forms a first side of the channel 96, the second side part 102 forms a second side of the channel, and the base part 40 forms a base or bottom of the channel. The first and second side surfaces 50 and 104, and the upper support surface 44 of the base part 40, define boundaries of the channel 96 The first and second side parts 48 and 102 are effectively configured to capture the side structure 22 between them, so as to restrict lateral movement of the side structure relative to the floor frame assembly 18 (in both the directions C-D). The second side part 102 can extend to the second height H2, although in the illustrated embodiment, it extends to a height H4 above the lower support surface 42 of the base part 40 which is less than the second height. This may provide reasonably good support for the side structure 22, whilst facilitating positioning of the side part in the channel 96, e.g by moving the side part into the channel from the side (in the direction C) until it contacts the side surface 50, and then lowering the side structure down to rest upon the upper support surface 44 of the base part 40.

The side perimeter frame member 34 is effectively generally L-shaped in cross-section, but other shapes are possible, depending for example upon whether it comprises a second side part 102, and the height of part (options then including generally U-shaped or generally C-shaped in cross section) As can be seen, the side parts 48 and 102 of the side perimeter frame member 34 are disposed generally perpendicular to the base part 40. The upper support surface 44 of the base part 40 is disposed generally horizontally during use of the unit 10, and the side surfaces 50 and 104 generally vertically. The first and second side surfaces 50 and 104 are generally parallel to one another. The upper surface 28 of the floor support portion 24 is effectively disposed above the base parts 40 of the perimeter frame members 32-38 At least a portion of the side part 48 of each of the perimeter frame members 32-38 extends above the upper surface 28 of the floor support portion 24. As explained above, the modular building unit 10 comprises internal walkway openings 80 and 82, and a walkway opening 92 which forms a main/front doorway for the building 56. The floor frame assembly 18 comprises doorway or walkway areas which define locations for these walkway openings 80, 82 and 92 in the modular building unit 10. This is best shown in Figs. 4 and 5, in relation to the internal walkway opening 80. The side perimeter frame member 34 comprises a walkway opening portion 108. As can be seen, the side part 48 in the region of the walkway opening portion 108 extends to a height J Is (above the base part lower surface 42) which is less than the second height H2, and which may be less than or equal to the third height H3. In the illustrated embodiment however, the height Hs is either the same as the height H3, or the same as a height of an upper support surface 110 of the floor structure 30. In this way, the floor structure 30 can easily match up with a floor height in the first building section 58. The walkway opening portion 108 is effectively formed by providing an aperture in the side part 48, e g by cutting away or removing a section of said side part, or by folding a section of said side part over.

As discussed above, a particularly suitable material for the structural frame is a metallic material, which could be cold-formed. The base part 40 of the side perimeter frame member 34 extends continuously between its lower surface 42 and its upper surface 44 The first height Hi therefore represents a depth of the base part 40, and may be in the range of about 3mm (~0.118") to about 5mm (~0.197"), in the case of metallic materials

The second height H2 is suitably at least around 200mm (-7.874”), but can be up to around 600mm (-23.622"). A particularly preferred option for the second height H2 may be up to around 400mm (-15.748"), optionally in a range of about 200mm to about 400mm. Providing the side part 48 of the perimeter frame member 34 with a second height H2 in this range may provide effective support for the side structure 22 without adding significant bulk or weight to the floor frame assembly 18. Factors impacting on the second height H2 may include a thickness of material forming the side part 48.

Referring now to Fig 12, there is shown a vertical cross-sectional view of part of a foundation 112 for the building 56, showing part of the modular building unit 10. The foundation 112 will be described in more detail below. The third height H3 of the floor support portion 24 may be up to about 70mm (-2.756"). This may provide the floor support portion 24 with an effective depth which is relatively shallow, and which may be significantly shallower than in conventional modular building units. In the hybrid building 56 comprising the first section 58 (constructed at the final location 62) and the second section 60 (comprising the modular building unit 10), the first section comprises a floor 114. A level of the floor 114 of the first section 58 can be brought up to that of the second section (i.e. H3) by applying e g. a cementitious screed 116 to a floor support structure 118 of the first section 58 (provided by the foundation 112). It may be preferred to restrict the third height I F, to no more than around 70mm, which may be a maximum optimal height for such a screed 116. The third height H3 may however be up to around 50mm (-1.968”), optionally in a range of about 50mm to about 70mm, and a height in the region of around 50mm may be preferred. As can be seen from Fig. 12, the floor support structure 30 brings the height of the floor in the module 10 up to the level Hs, and a corresponding floor structure 120 is positioned on the screed 116, and matches up with the floor support structure 30 (and so is at the height Hs). Typically, a decorative floor finish (not shown) will be provided on the floor structures 30 and 120, which can take one of many different forms, including but not limited to carpet, tiles, composite floor laminate, and a wood-based floor material.

Referring back to Fig. 5, the floor support portion 24 comprises a plurality of floor frame members which together form the portion, the floor frame members taking the form of joists 122. Thejoists 122 each have an upper surface 124, and together form the upper surface 28 which supports the floor structure 30, each surface 124 supporting a part of the floor structure. Where the structural frame 16 is of a metallic material (particularly cold-formed), thejoists 122 will typically be generally box-shaped in cross-section, or of an inverted U-shape, or C-shape. In a variation however, the floor support portion may be defined by a single or unitary structure which forms the upper surface. Options include a slab or plate, which may for example be of a cementitious material Referring to Fig 12, instead of thejoists 122, a slab 124 e g of concrete may therefore be provided which forms the floor support portion 24.

In a variation, at least part of the floor support portion 24 (not shown) may comprise an upper surface 28 which is at a fourth height above the lower surfaces 42 of said perimeter frame member base parts 40. The fourth height may be different to the third height Ha, and may for example be less than the third height Another and more preferred option however would be to provide a part of the floor structure 30 with a reduced depth, or to arrange the floor structure 30 so that it does not extend over a part of the floor support portion 24. Either option may provide e.g a depression or recessed area which may be configured to receive a pod having an integral floor (the pod e.g. containing a wet facility such as a bathroom, W/C or washroom, utility room or ensuite) One example of this can be seen in Figs. 9 and 10, where a W/C or washroom 126 can be provided as a pod (or module) which comprises an integral floor 128 that rests on the floor support portion 24. In this way, it may be possible to match a level of said integral floor 128 with the floor of the modular building unit 10.

Reference is made to various heights of features of the floor frame assembly 18. It will be understood that these heights should be taken in a generally vertical sense, and in normal use of a modular building unit 10 comprising the floor frame assembly 18. The heights are all taken with reference to the lower surfaces 42 of the base parts 40, which should be understood to be generally in a same plane, and so providing a common reference point The features whose heights are referred to should not necessarily be taken to be positioned vertically above said lower surfaces 42, and so could be displaced e.g. laterally relative to one or more of said lower surfaces.

In the illustrated embodiment, the side structure 22 forms external walls of the modular building unit 10, comprising left and right side walls 130 and 132, and front and back end walls 134 and 136. As can be seen particularly from Fig 1, these walls 130-136 are provided at a perimeter of the unit 10. The side structure 22 also comprises support posts or columns which extend between and connect the floor frame assembly 18 to the ceiling frame assembly 20. A support post is provided at each comer of the modular building unit 10, the posts indicated by numerals 138, 140, 142 and 144. Typically the posts 138-144 will be of a metallic material, which could be a hot or cold-formed metallic material Particularly where the comer posts 138-144 are of a cold- formed metallic material, at least one support post/column (not shown) may be provided at a location on the perimeter of the floor frame assembly 18 which is spaced from one or more of the comer posts The posts can be box-shaped, or U/C-shaped in cross section.

The support posts 138-144 each have a lower end which forms part of the bottom 46 of the side structure 22. Referring for example to the corner post 140, this comprises a lower end 146 which is located in the channel 96 defined by the right side perimeter frame member 34 The support posts 138-144 each have a side which forms part of the side of the side structure 22, and so is supported by the base part 48. Again referring to the post 140, see post side 148. The side structure 22 also comprises wall panels, at least some of which are coupled to a support post or posts 138-144 to form a wall, or part of a wall. Referring to the right side wall 132, wall panels 150-158 are shown. The wall panels 150-158 each have a lower end which forms part of the bottom 46 of the side structure 22, and a side which forms part of the side 52 of the side structure Referring to the wall panel 150, see bottom 160 and side 162 (Fig. 2). Other options for the side structure 22 exist, including structural insulated panels (SIPs), and other panels e.g. of a cement-based material. Such panels may form at least part of the bottom of the side structure, and at least part of the side Either way, the panels are intended to provide structural support to the modular building unit 10, which helps to reduce the complexity of the structural frame 16

Where the side structure 22 comprises or is defined by such panels 150-158, the panels comprise top and bottom frame members, and columns or posts extending between and connecting said frame members. Referring again to the panel 150 (see Fig 2), top and bottom frame members 164 and 166, plus first and second side posts 168 and 170 are shown in broken outline The top and bottom frame members 164, 166 may be of a first material, and the posts 168, 170 of a second material which is different to the first material. The first material may be the same as a material of the floor and ceiling frame assemblies 18 and 20, e.g where said frame assemblies are of a metallic material then the top and bottom frame members of the panel may also be of that metallic material. The second material may be a timber or timber-based material. This may provide an advantage of matching e.g. vertical shrinkage rates of timber materials used to form the first building section 58. It will be understood in such a case that vertical support posts e.g 140 may similarly be of the second material

Variations on the above include non-panel based options, which may for example comprise transverse bracing members provided between adjacent pairs of support posts. This is illustrated in Fig. 2, where first and second transverse bracing members are shown schematically at 171 and 173, extending between the adjacent posts 168 170. The bracing members 171 and 173 are arranged generally as a ‘K-brace’, and extend at a non- perpendicular angle between the posts 168, 170. Other transverse bracing members could extend between the posts 168 and 170 at different angles, e.g. substantially perpendicularly. Different bracing members may be provided between different pairs of posts.

Referring now to Fig 13, there is shown a further enlarged end view of the ceiling frame assembly 20, taken in the direction of the arrow A in Fig. 4. The ceiling frame assembly 20 comprises a ceiling support portion 172 comprising a plurality of ceiling frame members in the form of joists 174 having lower surfaces 176 configured to support a ceiling structure 178 The ceiling frame assembly 20 also comprises a perimeter frame 180 comprising a plurality of perimeter frame members which together form the frame These comprise first and second side frame members 182 and 184, and first and second end frame members 186 and 188 (Fig. 1). The first and second side frame members 182 and 184 respectively form left and right side frame members. The first and second end frame members 186 and 188 respectively form front and back frame members. As with the floor frame assembly 18, these frame members 182 to 188 typically have the same general structure, although one or more of the frame members may have a different structure Referring therefore to the right side frame member 184 shown in Fig.13, this comprises a top part 185 comprising an upper surface 187, and a lower surface 190 configured to support a top 192 of the side structure 22. The top part 185 is of a generally inverted L-shaped, or generally inverted U-shaped, structure. A first side part 194 is disposed transverse to the top part 188 and connected to it, and comprises a side surface 196 configured to support the side 52 of the side structure 22 A second side part 197 is spaced apart from the first side part 194 and parallel to it In the same way as the floor frame assembly 18, a channel 199 is defined, which receives the top 192 of the side structure 22. The frame member 184 is generally of an inverted L -shape, and so essentially an inverted version of the floor side frame member 132.

The ceiling support portion 172 is connected to the ceiling perimeter frame 180 Again the ceiling support portion can optionally be formed as a single or unitary structure, e.g. of a cementitious material. The modular building unit 10 can support the first building section 58, for example by connecting floor joists 198 of the first building section 58 to the ceiling frame assembly 20. Fig. 16 in particular shows a mounting lip or tongue 200 of a joist 198 positioned on the upper support surface 188 of the side perimeter frame member 184

The ceiling frame assembly 20 also comprises a plurality of mounting or spacing members, four shown and given the numeral 202 (Fig. 1) These mounting members 202 serve for mounting the further modular building unit 14 on the modular building unit 10, the unit 10 forming a lower unit and the unit 14 an upper unit The mounting members 202 protrude or extend from the upper surfaces of the ceiling perimeter frame members 182- 188, upwardly and/or in a generally vertical direction, away from the upper surface/extent of the ceiling frame perimeter members. These mounting members 202 take the form of a block, post, stub, pin or peg, and are connected to one of the perimeter frame members 182-188. In a variation, one or more of the ceiling frame perimeter members 182-188 may themselves be arranged to define at least one mount.

As can be seen particularly in Fig. 3, apertures are formed between adjacent mounting members 202, one such aperture indicated by numeral 204. This provides a pathway for utilities/buildmg services equipment (such as sewerage, ventilation, power and/or communication conduits) to pass into a void, space or gap between the stacked modular building units 10, 14. This may also provide the advantage that a void, space or gap 206 (Fig. 13) is formed between the two modular building units 10 and 14, which can accommodate e.g. utilities/building services equipment, such as sewerage pipes or conduits, ventilation pipes or ducts, power cables, and/or communication cables. The location of such building services equipment is shown generally in broken outline in Fig. 9, and indicated generally by numeral 208. These conduits 208 may connect to wet facilities in the upper modular building unit 14, which will be described below, and may ultimately pass through a service module 210 (Fig. 10) in the unit 10 to a sewer (not shown) The void 206 can be created with minimal additional structure, and so affords cost and weight savings The mounting members 202 each have an upper surface 212 (shown in broken outline in Fig 13) which is configured to contact a lower surface of the upper modular building unit 14 seated on the lower modular building unit 10, in particular a lower surface of a floor frame assembly 18' of the upper unit

The floor support portion 24 of the floor frame assembly 18 defines the first depth Di, as described above The ceiling support portion 172 defines a second depth D2, which is greater than the first depth Di A ratio of the first depth Di of the floor support portion 24 relative to the second depth Dzof the ceiling support portion 172 is at least about 1 :3. The second depth D2 of the ceiling frame portion 20 is defined between the upper surfaces 212 of the mounting members 202 and the lower surface 176 of the ceiling support portion 172 (defined by its frame members 174) The ratio of the first depth Di relative to the second depth D2inay be up to about 1 :6, and may be in a range of between about 1 :3 to about 1 :6 A ratio falling within this range may provide a good balance of a relatively thin floor frame assembly 18, and a ceiling frame assembly 20 that can provide a majority of the structural strength for the modular building unit, and/or space to accommodate e.g. utilities/building services equipment. The second depth D2of the ceiling frame assembly 20 may be at least about 150mm (~5.906"), may be up to about 300mm (~11 8H"), and may be in a range of about 150mm to about 300mm A depth in the region of about 250mm (~9 843 ") may be preferred. A modular building unit having such floor and ceiling frame assembly first and second depths may provide a good balance of benefits, e.g. in terms of minimising disruption to accommodate the floor frame assembly and/or minimising a depth of structure at a transition between lower and upper modular building units, whilst providing a sufficiently strong ceiling frame assembly and/or depth in the ceiling frame assembly to accommodate utilities/building services equipment

The floor structure 30 is generally planar, and is positioned on the joists 28, as indicated by the arrow E in Fig. 4. The floor structure 30 defines a floor of the modular building unit 10, and is typically defined by one or more planar floor panel. Many options for forming the floor structure 30 exist, but preferred options include timberbased materials for the panel(s), such as oriented strand board (OSB), chipboard, fibreboard and plywood. The first depth Di of the floor support portion 24 does not include the floor structure 30, other structural or insulative material positioned on said floor structure, and/or any decorative floor finish or covering (e g. carpet or tiles) positioned on the floor structure. The ceiling frame assembly 20, in particular its ceiling support portion 172, is configured to support the ceiling structure 178, which is also generally planar. The ceiling structure 178 defines a ceiling of the modular building unit 10, and is defined by one or more planar ceiling panel. Many options for forming the ceiling structure 178 exist, but preferred options include plasterboard panels or sheets. The second depth D2 of the ceiling frame assembly 20 does not include the ceiling structure 178, other structural or insulative material connected to the ceiling structure, and/or any decorative finish or covering (such as a cementitious coating) applied to the ceiling structure.

As can be seen in Figs. 10 and 11, the modular building unit 10 defines a plurality of rooms within the building 56, at least some of which provide wet facilities in the form of a W/C or washroom 126, and a utility room 210. The unit 10 is arranged so that it comprises internal walls which define a boundary or boundaries of the washroom 126 and utility room 210. Referring for example to the washroom 126, in a variation on the pod options discussed above, the unit 10 can include internal walls 214 and 216 which, together with the front end wall 134 and left side wall 130, define a space that forms the washroom. The washroom 126 and utility room 210 are accessed from the hallway 94 and open plan area 84 of the circulation space 64.

In a similar fashion, the upper modular building unit 14 comprises rooms providing wet facilities in the form of a bathroom 218 which is accessed via the landing 78 of the circulation space 64 As explained above, sewerage conduits 208 connecting to washing and toilet facilities in the bathroom 218 can be accommodated at least partly in the void 206 between the units 14 and 10. This can include, for example, sewerage connections for a toilet 220, bath 222 and sink 224

In the illustrated building 56, the modular building units 10 and 14 are enclosed within an external layer 226, which can be of any suitable form, as described in the International patent applications referred to above Options include panels, cladding, and/or brick/block. One particularly preferred option may be to form the second building section 60 from structural insulated panels (SIPs) which effectively enclose or envelope the modular building assembly 12 (comprising the units 10, 14) forming the first building section 58. The modular building units 10, 14 can however be arranged to define at least part of a perimeter of the building, in particular an external perimeter. This can be achieved by arranging panels forming at least some of the walls as external cladding panels.

The provision of a modular building unit 10 having the depth relationship between its structural frame floor and ceiling assemblies 18 and 20 (which effectively requires that D2> 3Di) may provide particular benefits in the context of the hybrid building 56 described above. This includes facilitating matching the floor level of the second building section 60 with the floor level of the first section 58 constructed at the final location 62. In particular, the first and second building sections 58 and 60 may rest on a common foundation, provided by the foundation 112 (Fig. 12) The foundation 112 supports both the second building section 60 (defined by the modular building assembly 12), and the first building section 58.

It can be desirable to maintain common (or uniform) floor levels within the constructed building 28, to avoid a change in floor height between the building sections 58 and 60 Providing the modular building unit structural frame 16 with floor 18 and ceiling 20 frame assemblies having the stated depth relationship may have the result that the floor frame assembly depth Di can be relatively shallow, so that only a small height difference need be accommodated by the first building section 58. This may provide benefits in terms of material and cost savings. In addition, arranging the floor 18 and ceiling 20 frame assemblies so that they have depths Di and D2 in the stated ratio may have the result that the ceiling frame assembly can be relatively deep, without adversely impacting the depth of the floor frame assembly. This may enable the ceiling frame assembly 20 to provide a majority of the structural strength for the modular building unit 10, and space to accommodate utilities/building services equipment. The shallow floor frame assembly may also help to reduce a depth of structure at the intersection between the ceiling frame assembly 20 of the (lower) modular building unit 10, and the floor frame assembly 18' of the upper unit 14 (said depth defined between an upper surface 28' of a floor support portion 24' of the floor frame assembly 18', and the lower surface 176 of the ceiling frame assembly 20). This can facilitate extension of the staircase 70 from the lower unit 10 into the upper unit 14, by reducing a depth of structure that an upper step (or steps) of the staircase must accommodate as it passes from the ceiling frame assembly 20 of the lower unit through the floor frame assembly 18' of the upper unit 14.

The foundation 1 12 is an insulated foundation, comprising the floor structure 118 (which provides a load bearing structure for the building 56) and thermal insulation 228 The modular building unit 10 is located on the foundation 112 so that the load bearing structure 118 provides structural support for the unit, and so that the thermal insulation 228 thermally insulates the modular unit relative to the ground 72.

Numerous options for forming the thermal insulation 228 exist, including constructing it from a series of shaped blocks (not shown) of a suitable insulating material which can bear the load of the completed building 56 Examples include Isoquick® insulation blocks commercially available in the UK from Build Homes Better Ltd, which can be arranged to form an insulation raft or pad. The blocks are formed from a water-resistant polymeric foam material, in particular Peripor® available from BASF SE. The blocks forming the thermal insulation 228 are typically arranged in two interlocking layers (not shown), with interlocking features such as protrusions and recesses provided at an interface between the layers

The thermal insulation 228 provides a surface 230 on which the load bearing structure 118 can be positioned, and in the illustrated embodiment, provides a substantially continuous surface. The load bearing structure 118 is located on the surface 228 following positioning of the thermal insulation 228 on the ground 232. The load bearing structure 118 is insulated relative to the ground 232 by the thermal insulation 228, so that thermal energy transfer between the load bearing structure and the ground is resisted. This in turn insulates the modular building unit 10 (located on the foundation 112) relative to the ground 232, reducmg/preventmg thermal bridging between the unit and the ground

The load bearing structure 118 can take the form of a layer of reinforced concrete, which can be formed at the final location 62 for the building, in a conventional fashion. Moisture barrier layers (not shown) can be positioned below the thermal insulation 228, and between the upper surface 230 of the thermal insulation and a lower surface of the load bearing structure 118. The moisture barriers may take any suitable form known in the field of the invention Particularly suitable options may include: a moisture resistant sheet, which may be a substantially impermeable membrane e.g. of a polymeric material such as polyethylene.

The various frame members forming the perimeter frame 26 can be arranged to transfer loads directly to the foundation 112, and may be arranged so that they are line-loaded, so as to more evenly distribute such loads across the foundation (in comparison e g. to a point-loaded structure, such as a light gauge structure). In particular, each of the side and end frame members 32-38 can be arranged in contact with the load bearing structure 118 of the foundation, to more evenly transfer loading from the modular building unit 10 to the foundation. This can most suitably be achieved by constructing the perimeter frame 26 of e.g a hot-formed metallic material as described above, loading imparted on the beams being distributed more evenly along their lengths than in a point loaded structure Thus loads not only of the modular building unit 10 itself, but loads applied to it e g by the upper modular building unit 14, can be transferred more evenly to the foundation load bearing structure 118. This can also apply to the joists 124, which may similarly be of a hot-formed metallic material, and arranged in contact with the load bearing structure 188 of the foundation.

Optionally, one or more support beam may be provided, which may be separate from the joists 124. A first support beam 231 (shown in broken outline in Fig 4) can be provided extending e g in a direction between the first and second end frame members 36 and 38, and disposed between the side frame members 32 and 34. At least one further e.g second support beam 233 can be provided, extending e.g. between the left side frame member 32 and the first support beam 231 The support beams 231 and 233 provide additional structural rigidity, and can support internal wall structures in the modular building unit 10.

At least some of these joists 124, and/or one or more the support beams 231 and 233, may further be arranged so that they are substantially aligned with structural features of or in the upper modular building unit 14, in particular similar support beams in a floor frame portion of the upper unit, and/or internal walls of the upper unit (which may transfer loads through the upper unit’s floor frame assembly to the lower modular building unit 10) Arranging the floor frame assembly 18 in this way may have the advantage that a material forming the thermal insulation 228 can be less dense, and/or can have a lower compressive strength. This can be beneficial because, generally speaking, insulation materials which are more dense, and/or which have a higher compressive strength, tend to be more costly.

In a variation for, the foundation 112 may be formed by positioning the load bearing structure 118 on or in the ground 232, with the thermal insulation 228 positioned on the load bearing structure and supporting the modular building unit 10 (and the first building section 58). It will be understood that the thermal insulation will then be required to have sufficient load bearing capacity to bear structural loads imparted upon it by the modular building unit 10, and indeed by a remainder of the building 56. In a further variation, the load bearing structure may be formed from pre-cast blocks or beams (not shown).

As mentioned above, the upper modular building unit 14 can be a unit according to the invention. The unit 14 thus comprises a structural frame 16' having the floor frame assembly 18', a ceiling frame assembly 20', and a side structure 22'. The depth of the structure at the intersection between the lower unit ceiling frame assembly 20 and the upper unit floor frame assembly 18' is typically in the range of 200mm to 300mm, bearing in mind the optional depth ranges for Di and D2 discussed above. This can be particularly beneficial in terms of material savings, and reducing complexity of a transition for the staircase 70 as it passes between the two units 10, 14. The upper unit 14 is mounted on the lower unit 10 at the final location 62, following location of the lower unit on the foundation 1 12. The upper modular building unit 14 is connected to the lower unit 10 to form the assembly 12, in order to resist particularly lateral movement of the units relative to one another. Various options exist for connecting the units 10 and 14, including welding, bonding and mechanical fixings. Suitable mechanical fixings can include nut and bolt assemblies, pms and locating sockets, and threaded fasteners such as self-tapping screws, and the like. Reference is made in this document to a ceiling frame assembly of the modular building unit 10, and to a ceiling of the unit Reference to a ceiling frame assembly 20 (and a ceiling) should be taken to mean an upper structure which covers or encloses an internal volume of the modular building unit 10. It will be understood that the ceiling frame assembly 20 of the modular building unit 10 will not typically provide a weather-resistant roof structure intended to prevent e.g. water ingress into the modular building unit. To this end, and referring to Fig. 7, a separate roof structure 234 is shown which is constructed e g from a plurality of roof trusses (not shown) The roof structure 234 bridges across the first and second building sections 58 and 60, and weatherproofs the building 56 However, the modular building unit 10/14 could optionally provide such a roof, for example by arranging the ceiling frame portion to additionally provide or define an external or outer roof for the unit. This may be an option particularly e.g. for single storey buildings comprising the modular building unit, or where the unit forms an uppermost storey of a building Suitable options can include a flat roof structure

In a variation on the illustrated embodiment, the building may be a modular building comprising a plurality of modular building units which form all (or at least a majority) of an internal volume of the building This is illustrated in Fig. 14, which is a wire -frame isometric view of a plurality of modular building assemblies, configured to form part of a building 56" Like components of the building 56'' with the building 56 share the same reference numerals, with the addition of the suffix ". The building 56" comprises a plurality of modular building units, at least one of which is a modular building unit according to the invention. In a particularly preferred option, all of the modular building units are units according to the invention.

The modular building units are arranged in assemblies stacked as discussed above in relation to the modular building assembly 12. Thus a modular building assembly 12" comprises a lower modular building unit 10" and an upper modular building unit 14" stacked on the lower unit. A further modular building assembly 12a" similarly comprises a lower modular building unit 10a" and an upper modular building unit 14a" stacked on the lower unit Between them, the modular building units of the assemblies 12" and 12a" define the entire internal volume of the building 56", with the exception of an upper or outer roof of the building (not shown), which may be formed at a final location for the building (as for the roof structure 234), or formed as a modular (transportable) structure.

Turning now to Fig. 15 there is shown a ceiling frame assembly 20"' of a modular building unit 10'" according to another embodiment of the invention. The ceiling frame assembly 20'" differs in that it comprises a ceiling perimeter frame 180"' having perimeter frame members of a different shape/structure Only the differences will be described here Like components of the ceiling frame assembly 20'" with the ceiling frame assembly 20 will be described. In this case, a right side frame member 184"' of the ceiling frame assembly 20'" is shown, which has a different shape to the right side frame member 184 of the assembly 20. In this instance, the right side frame member 184'" comprises a second side part 197"' which includes a protrusion in the form of a support ledge, flange or the like 236 on which the joists 198 of the first building section 58 rests.

Fig. 16 shows a ceiling frame assembly 20^IV of a modular building unit 10 ^IV according to a further embodiment of the invention. The ceiling frame assembly 20^IV again differs in that it comprises a ceiling perimeter frame 180^IV having perimeter frame members of a different shape/structure Only the differences will be described here Like components of the ceiling frame assembly 20 ^IV with the ceiling frame assembly 20 will be described. In this case, a right side frame member 184^IV of the ceiling frame assembly 20^IV is shown, which has a different shape to the right side frame member 184 of the assembly 20. In this instance, the right side frame member 184^IV comprises first and second side parts 194^IV and 197 ^IV which each includes protrusions in the form of support ledges, flanges or the like 238 and 240 Ceiling frame members 174^IV of a ceiling support portion 172^IV of the ceiling frame assembly 20^IV rest on the support ledge 238, whilst the joists 198 of the first building section 58 rests on the support ledge 240.

Variations on the illustrated ceiling frame assemblies of Figs. 13, 15 and 16 can share features of the various embodiments

The invention extends to the following features of a ceiling frame assembly. Referring to the ceiling frame assembly 20 shown in Fig. 13, the assembly comprises the ceiling support portion 172, having the lower surface 176 configured to support (or define) at least part of a ceiling structure of the modular building unit 10. The ceiling frame assembly also comprises the perimeter frame 180, which comprises the plurality of perimeter frame members 182-188 Referring to the side frame member 184, this comprises the top part 185, comprising upper surface 187, and lower surface 190 (configured to support the top 192 of side structure 22). The side frame member 184 also comprises the side part 194, which is disposed transverse to the top part 185 and connected to it, and which comprises the side surface 196 configured to support the side 52 of the side structure 22. The lower surface 190 of the top part 185 is disposed a first distance Da below the upper surface 187. At least a portion of the side part 194 extends to a second distance D4 below the upper surface 187, which is greater than the distance Da. The ceiling support portion 172, which is connected to the perimeter frame 180, is arranged so that its lower surface 176 is disposed a distance Ds below the upper surface 187 of the top part 185, which is greater than the distance D3 but less than the distance D4. As can be seen therefore, the lower surface 176 of the ceiling support portion 172 is disposed below the top parts 185 of the perimeter frame members 182- 188. At least a portion of the side part 194 of each of said perimeter frame members 182-188 extends below the lower surface 176 of the ceiling support portion 172.

Various modifications may be made to the foregoing without departing from the spirit or scope of the present invention.

Further aspects and/or embodiments of the invention may combine the features of one or more aspect and/or embodiment disclosed in this document. Accordingly, such further aspects and/or embodiments may comprise one or more feature selected from one or more aspect or embodiment of the invention disclosed in this document.

Unless explicitly implied by context or stated in the document, the features of any method or process disclosed in this document need not necessarily be performed in the precise order set out in the relevant text and/or drawings Accordingly, any method or process disclosed in this document may be capable of being performed in an order other than that specifically set out in the relevant text/drawings, if circumstances permit.

Features disclosed in this document (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise Accordingly, features disclosed in this document may represent only one example of a generic series of equivalent or similar features.

Claims

1. A floor frame assembly for a structural frame of a modular building unit, the floor frame assembly comprising: a floor support portion comprising an upper surface configured to support at least part of a floor structure of the modular building unit; and a perimeter frame comprising a plurality of perimeter frame members, at least some of the perimeter frame members comprising: a base part comprising a lower surface, and an upper surface configured to support a bottom of a side structure of the modular building unit; and a side part disposed transverse to the base part and connected to it, the side part comprising a side surface configured to support a side of the side structure; in which the upper surface of the base part of each of said perimeter frame members is disposed at a first height above the lower surface; in which at least a portion of the side part of each of said perimeter frame members extends to a second height above the lower surface of the respective base part which is greater than the first height; and in which the floor support portion is connected to the perimeter frame, and the upper surface of the floor support portion is disposed at a third height above the lower surfaces of said perimeter frame member base parts, the third height being greater than the first height and less than the second height.

2. A floor frame assembly as claimed in claim 1, in which the lower surfaces of the base parts of said perimeter frame members are configured to define at least part of a base of the floor frame assembly, the lower surfaces provided lowermost on the floor frame assembly.

3. A floor frame assembly as claimed in either of claims 1 or 2, in which the base part is provided integrally with the side part.

4. A floor frame assembly as claimed in any preceding claim, in which said perimeter frame members each define a channel shaped to receive the side structure, the channel being defined at least partly by the base part and the side part, the channel being open at least at an upper end, for receiving the side structure

5. A floor frame assembly as claimed in any preceding claim, in which the side part is configured to restrict lateral movement of the side structure relative to the floor frame assembly in at least one direction, which direction is a generally horizontal direction in use, through contact between its side surface and the side of the side structure

6. A floor frame assembly as claimed in any preceding claim, in which the side part is a first side part, the side surface is a first side surface, and said perimeter frame members each comprise a second side part which defines a second side surface configured to support a further side of the side structure

7 A floor frame assembly as claimed in claim 6, in which the second side part is disposed transverse to and connected to the base part, and spaced apart laterally relative to the first side part.

8. A floor frame assembly as claimed in claim 7, in which said perimeter frame members each define a channel shaped to receive the side structure, and in which the channel is defined by the base part and the first and second side part, the first and second side parts configured to capture the side structure between them so as to restrict lateral movement of the side structure relative to the floor frame assembly

9. A floor frame assembly as claimed in any one of claims 6 to 8, in which the second side part extends to a height above the lower support surface of the base part which is less than the second height.

10. A floor frame assembly as claimed in any preceding claim, in which said perimeter frame members are generally L-shaped or generally U-shaped in cross-section.

11. A floor frame assembly as claimed in any preceding claim, in which the floor frame assembly comprises one or more walkway area defining a location for a walkway in the modular building unit

12. A floor frame assembly as claimed in claim 11, in which one or more portion of one or more of the side parts extends to a height which is less than the second height, said portion defining the walkway area.

13. A floor frame assembly as claimed in any preceding claim, in which the second height is in a range of about 200mm to about 400mm.

14. A floor frame assembly as claimed in any preceding claim, in which the third height is in a range of about 50mm to about 70mm.

15. A floor frame assembly as claimed in any preceding claim, in which at least part of the floor support portion comprises an upper surface which is at a fourth height above the lower surfaces of said perimeter frame member base parts, the fourth height being less than the third height, to define a depression or recessed area which is optionally configured to receive a pod having an integral floor.

16. A floor frame assembly as claimed in any one of claims 1 to 14, in which a part of the floor structure has a reduced depth, or the floor structure is arranged so that it does not extend over a part of the floor support portion, to define a depression or recessed area which is optionally configured to receive a pod having an integral floor.

17. A structural frame comprising the floor frame assembly of any one of claims 1 to 16, a ceiling frame assembly and the side structure, the side structure extending between and connecting the floor frame assembly to the ceiling frame assembly.

18 A modular building unit comprising a structural frame and a floor structure, the structural frame comprising a floor frame assembly, a ceiling frame assembly, and a side structure extending between and connecting the floor frame assembly to the ceiling frame assembly, in which the floor frame assembly comprises: a floor support portion comprising an upper surface configured to support at least part of the floor structure; and a perimeter frame comprising a plurality of perimeter frame members, at least some of the perimeter frame members comprising: a base part comprising a lower surface, and an upper surface configured to support a bottom of the side structure; and a side part disposed transverse to the base part and connected to it, the side part comprising a side surface configured to support a side of the side structure; in which the upper surface of the base part of each of said perimeter frame members is disposed at a first height above the lower surface; in which at least a portion of the side part of each of said perimeter frame members extends to a second height above the lower surface of the respective base part which is greater than the first height; and in which the floor support portion is connected to the perimeter frame, and the upper surface of the floor support portion is disposed at a third height above the lower surfaces of said perimeter frame member base parts, the third height being greater than the first height and less than the second height.

19. A modular building unit as claimed in claim 18 in which the side structure forms one or more external wall of the modular building unit, said one or more wall provided at a perimeter of the unit.

20. A modular building unit as claimed in either of claims 18 or 19, in which the side structure comprises support posts provided at one or more comer of the modular building unit, and one or more wall panel coupled to a support post or posts to form at least part of a wall; in which the support posts have: a lower end which forms part of the bottom of the side structure; and a side which forms part of the side of the side structure; in which the one or more wall panel has a lower end which forms part of the bottom of the side structure and a side which forms part of the side of the side structure.

21. A modular building unit as claimed in any one of claims 18 to 20, in which the side structure comprises or is defined by a panel, the panel comprising top and bottom frame members, and columns or posts extending between and connecting said frame members.

22. A modular building unit as claimed in any one of claims 18 to 21, in which the ceiling frame assembly comprises: a ceiling support portion comprising a plurality of ceiling frame members having lower surfaces configured to support a ceiling structure; and a perimeter frame comprising a plurality of perimeter frame members, at least some of the perimeter frame members comprising: a top part comprising an upper surface, and a lower surface configured to support a top of the side structure; and a side part disposed transverse to the top part and connected to it, the side part comprising a side surface configured to support a side of the side structure; in which the ceiling support portion is connected to the ceiling perimeter frame

23. A modular building unit as claimed in claim 22, in which the ceiling frame assembly comprises a plurality of mounting members which serve for mounting a further modular building unit on the modular building unit, the mounting members each extending from an upper surface or extent of a ceiling perimeter frame member

24. A modular building unit as claimed in claim 23, in which one or more aperture is formed between adjacent mounting members, which may provide a pathway for building services equipment.

25 A modular building unit as claimed in either of claims 23 or 24, in which the mounting members comprise an upper surface configured to contact a lower surface of a further modular building unit seated on the modular building unit.

26. A modular building unit as claimed in claim any one of claims 18 to 25, in which the floor support portion defines a first depth, and the ceiling support portion defines a second depth which is greater than the first depth, a ratio of the first depth of the floor support portion relative to the second depth of the ceiling support portion be at least about 1 :3.

27. A modular building unit as claimed in claim 26, in which the ratio of the first depth relative to the second depth is up to about 1 :6.

28. A modular building unit as claimed in either of claims 26 or 27, in which the second depth of the ceiling frame assembly is in a range of about 150mm to about 300mm.

29. A modular building unit as claimed in claim any one of claims 18 to 28, in which the modular building unit defines a circulation space configured to provide at least one access function for a building comprising the modular building unit, the access function selected from the group comprising: access between upper and lower living spaces of the building; access between a first living space and at least one further living space of the building, said living spaces being isolated from one another within another part of the building; and access into the building from an exterior of the building.

30. A building comprising the modular building unit of any one of claims 18 to 29

31 A building as claimed in claim 30, in which the building is a hybrid residential building comprising a first building section and a second building section, the first building section being an on-site construction at a final location for the building, and the second building section comprising the modular building unit, the first and second building sections configured to be connected at the final location to form the building

32 A building as claimed in claim 31 , comprising a plurality of modular building units according to any one of claims 18 to 28.

33. A method of constructing a hybrid building comprising the steps of: constructing a first building section at a final location for the building; at a location away from the final location, constructing a modular building unit according to any one of claims 18 to 29 to a substantially assembled form; transporting the modular building unit to the final location in the substantially assembled form, and arranging the modular building unit to form at least part of a second building section of the building; and connecting the first and second building sections to form the building.

34. A method as claimed in claim 33, comprising constructing a foundation for the building, including providing the foundation with a load bearing structure and thermal insulation, the method further comprising locating the modular building unit on the foundation so that the load bearing structure of the foundation provides structural support for the modular building unit, and so that the thermal insulation of the foundation thermally insulates the modular building unit relative to the ground.