WO2014056024A1

WO2014056024A1 - A building unit assembly

Info

Publication number: WO2014056024A1
Application number: PCT/AU2013/001150
Authority: WO
Inventors: Epaminondas Katsalidis
Original assignee: UNITISED BUILDING Ltd
Current assignee: UNITISED BUILDING Ltd
Priority date: 2012-10-09
Filing date: 2013-10-07
Publication date: 2014-04-17
Anticipated expiration: 2015-04-09

Description

A building unit assembly

Field of the invention

The present invention relates to building unit assemblies that are assembled to be structurally self supporting prior to positioning to form a building, as well as elements, structures and methods used in their construction. The invention is applicable to high rise buildings, low rise buildings and single storey buildings, in various embodiments.

Background of the invention

There have been many proposals to utilise prefabricated building methodologies in order to enable inexpensive and fast construction of buildings. Many of these constructions are modular in their approach so that there is an inherent inflexibility that limits their application.

Typically, prefabricated modules are mostly or fully assembled in a factory and transported to site, where they are lifted into position by a crane.

It is a desired object of the present invention to provide an alternative building unit assembly with an improved rnanufacturability, and that reduces labour and component numbers and thus cost.

Reference to any prior art in the specification is not, and should not be taken as, an acknowledgment or any form of suggestion that this prior art forms part of the common general knowledge in Australia or any other jurisdiction or that this prior art could reasonably be expected to be ascertained, understood and regarded as relevant by a person skilled in the art. Summary of the invention

Reference to prefabrication or assembly is reference to being a structurally self supporting unit prior to being positioned as part of the building. Such assembly may occur prior to the construction of the building, or units may be assembled once construction of the building has commenced.

The present invention provides a building unit assembly of a rectilinear box frame construction, which is structurally independent and self supporting in terms of its own weight and the live loads it will carry, and is also able to, when stacked, carry the load of the unit(s) above. According to a first aspect, there is provided a self supporting building unit assembly for use in constructing a building, including floor formwork and a plurality of structurally supporting columns for attachment to a vertically adjacent building unit assembly, whereby the floor formwork is able to receive and support a poured infill material.

According to a second aspect, there is provided a self supporting building unit assembly for use in constructing a building, whereby the building unit assembly includes floor formwork and at least two closed frame segments formed from two upright columns joined by upper and lower tie beams, whereby the floor formwork is able to receive and support a poured infill material and whereby the closed frame segments provide structural support to the constructed building. According to a third aspect, there is provided a self supporting building unit assembly having structure defining a rectilinear box including floor formwork and a plurality of structurally supporting columns or studs, wherein the floor formwork is able to receive and support a poured infill material, and whereby the infill material is poured about the feet of the columns or studs. Preferably, two studs are formed integrally with a sheet section extending therebetween to create a panel member. According to a fourth aspect, there is provided a building unit assembly including floor formwork and a plurality of vertically extending panel members including two spaced apart vertical studs formed with a sheet section extending therebetween, whereby the floor formwork is able to receive and support a poured infill material and whereby the studs are capable of structurally supporting another building unit assembly placed on top.

Preferably, the two studs are integrally formed with the sheet section and may be folded or roll-formed from sheet steel.

The vertically extending panel members may be spaced apart along opposing side walls of the building unit assembly creating spaced rectangular openings or voids. Alternatively, they could abut or join together to create a continuous wall.

The floor formwork advantageously comprises a plurality of adjacent floor panel members. The floor panel members preferably abut against each other to create a continuous surface. According to a fifth aspect, there is provided a self supporting building unit assembly including floor formwork created from a plurality of panel members that abut or join together, whereby the upper surface of the formwork is substantially level such that the subsequent poured infill material self levels.

The floor panel members preferably include a sheet section with two depending wall sections to create a top-hat configuration. The depending walls preferably include outwardly extending flanges. Advantageously, the sheet section and walls extend further at each end than the flanges. The sheet section preferably includes one or two undercut bends in the sheet section, to create a lateral groove or grooves into which the infill material can flow and set to form a positive engagement between the floor formwork and the infill material. The grooves may open inwardly or outwardly.

The depending wall sections preferably create a channel between two abutting panel members. A void may be created under the sheet section between the two wall sections into which the infill material cannot penetrate. The infill material is preferably concrete or gypsum, or another suitable material to create a floor slab. The infill material advantageously casts-in the vertical columns, closed frame segments and/or vertical panel members and locks them to the floor and floor formwork. The building unit assemblies of the first, second and fifth aspects preferably include at least two opposing side walls including a plurality of vertically extending panel members spaced apart from each other, the panel members including two spaced apart vertical studs formed with a sheet section extending therebetween, whereby the panel members are connected through the sheet section at their upper and lower ends to longitudinal members running the length of the side walls of the building unit assembly, such that a rigid joint is created and the building unit assembly is structurally self supporting. Preferably, the two spaced apart vertical studs are integrally formed with the sheet section.

According to any of the first to fifth embodiments, typically, the panel members would be folded or roll-formed from sheet steel. Advantageously, the studs would include at least a first portion extending substantially perpendicularly to the sheet section, and at least one flange section extending from the first portion, preferably substantially perpendicularly, such that the flange section is parallel to the sheet section. Such configuration may form what is known as a top-hat shape. The first portion may be inclined outwardly from the sheet section to the flange, such that a plurality of top-hat shaped panel members may be stacked in a nested configuration.

Advantageously, the distance between the centres of the two flange sections is in the range of 350mm to 750mm, more preferably 600mm. When positioned in the building unit assembly, preferably the first portion extends inwardly from the sheet section, with the sheet section forming the outer wall of the building unit assembly.

The wall panel members are spaced apart such that respective studs on adjacent panel members are spaced apart a distance of 350 to 750mm measured from the centre of each stud, more preferably 600mm. The building unit assembly preferably further includes roof panel members extending horizontally between the two upper longitudinal members. The roof panel members may include two spaced apart joists integrally formed with a sheet section extending therebetween. Advantageously, the vertical studs of the wall panel members align with corresponding roof and floor horizontal joists or side walls of the floor panel members to create a rigid loop around the building unit assembly. In some aspects, the vertically extending panel members support the weight of another building unit assembly placed on top. In a preferred embodiment, the roof panel members and the wall panel members are positioned in an alternating configuration. In alternative embodiments the panels may not alternate. The wall panels may be spaced or omitted to create openings for doors e.g. to create open living spaces, corridors, rooms etc spanning two adjoining units. The floor panel members may also be positioned in an alternating configuration to the vertical panel members, or more preferably are abutting to create a continuous floor surface.

The longitudinal members are preferably corner angles having a first plate and a perpendicular second plate. The sheet section of the wall panel members abuts against the first plate of the upper and lower longitudinal members, typically on the outer side of the first plate, for connection across the length of the aligned flat surfaces. Preferably, the sheet sections are connected at two or more, preferably three, points along the width of the sheet section. Such connection may be spot welding or alternative connections such as taxing, riveting or MIG welding. The sheet section of the wall panel members forms the bracing element for the vertical studs to create said rigid joint, thereby forming a Vierendeel truss construction. The lower longitudinal members could also be channel sections or angles having a return lip along their top edge.

The building unit assembly according to the fourth aspect of the invention is typically applicable to single storey or low rise buildings. Such a construction can be strengthened for high rise application by the addition of structurally supporting columns. The structurally supporting columns of the first and third aspects may be in the form of columns having a rectangular tubular cross-section or an I-beam. Such columns on either side of the building unit assembly may or may not be joined by tie beams extending across the width of the assembly. The structurally supporting columns may include an upper tie beam, and additionally a lower tie beam. The columns and upper and lower tie beams may be prefabricated to form a closed frame segment of rectangular configuration.

According to a sixth aspect, there is provide a method of assembling a building unit assembly for use in constructing a building, including: positioning a floor formwork having at least two tie beams extending across the width of the floor formwork; pouring infill material into the floor formwork; positioning at least two structurally supporting column assemblies including two upright columns joined by an upper tie beam; affixing respective column assemblies to a respective formwork tie beam to create a closed frame segment such that the building unit assembly is structurally self supporting.

According to a seventh aspect, there is provided a method of building a building using a plurality of building unit assembles according to the first aspect of the invention, wherein the infill material has been poured into the floor formwork during assembly of the building unit assemblies, the method including the steps of: lifting the building unit assemblies into position in the building so that each level of the building includes a predetermined number of units; connecting adjacent units to one another in each level; and connecting units in one level to corresponding units in at least one adjacent level that is vertically above or below the one level. According to a eighth aspect, there is provided a method of building a building using a plurality of building unit assemblies according to any one of the first to fifth aspects of the invention, the method including the steps of: lifting the building unit assemblies into position in the building to create at least one level of a predetermined number of units; connecting adjacent units to one another in each level; pouring infill material into the floor formwork of each unit to create the floor(s) of the building.

Where the building includes more than one level, there is a further step of connecting units in one level to corresponding units in at least one adjacent level that is vertically above or below the one unit.

The pouring of the infill material may be performed level by level, as the building is erected, for example a level of units is constructed and the infill material is poured for the floor of that level before the next level of units are positioned above the first level. Alternatively, all of the units in a building are positioned and connected to create the building's skeleton and then all of the floors are poured successively.

The building may include at least one core, whereby units adjacent to a core are connected to the core. The vertical loads between adjacent levels are preferably transmitted mainly through the building unit assemblies and the lateral loads may be transmitted to the core.

According to a ninth aspect, the present invention provides a building unit assembly having at least two opposing side walls including a plurality of vertically extending panel members spaced apart from each other, the panel members including two spaced apart vertical studs formed with a sheet section extending therebetween, whereby the panel members are connected through the sheet section at their upper and lower ends to longitudinal members running the length of the side walls of the building unit assembly, such that a rigid joint is created and the building unit assembly is structurally self supporting.

Preferably, the two spaced apart vertical studs are integrally formed with a sheet section. The building unit assembly of the ninth aspect may further include a plurality of structurally supporting columns for supporting another building unit assembly placed on top. The structurally supporting columns may include upper tie beams, and additionally may include lower tie beams. The columns and upper and lower tie beams may be prefabricated to form a closed frame segment of rectangular configuration. Preferably, the two spaced apart vertical studs are integrally formed with the sheet section. Typically, the panel members would be folded or roll-formed from sheet steel. However, it will be appreciated that in certain embodiments the panel members can be produced by alternate methods and using other materials. Advantageously, the studs would include at least a first portion extending substantially perpendicularly to the sheet section, and at least one flange section extending from the first portion, preferably substantially perpendicularly, such that the flange section is parallel to the sheet section. Such configuration may form what is known as a top-hat shape. The first portion may be inclined outwardly from the sheet section to the flange, such that a plurality of top-hat shaped panel members may be stacked in a nested configuration. The building unit assembly preferably further includes floor panel members extending horizontally between two lower longitudinal members. The floor panel members may include two spaced apart joists integrally formed with a sheet section extending therebetween.

According to a tenth aspect, there is provided a method of assembling a building unit, including: positioning an end frame, having two upright columns joined by at least one tie beam, with respect to two longitudinal members that extend perpendicularly to the tie beam; progressively assembling the building unit by positioning a plurality of vertically extending panel members in spaced apart relation along the two longitudinal members, the panel members including two spaced apart vertical studs formed with a sheet section extending therebetween; connecting the panel members through the sheet section at their upper and lower ends to the longitudinal members, such that a rigid joint is created and the building unit assembly is structurally self supporting.

The length of the building unit is determined by the length of the longitudinal members. The longitudinal members are preferably held in a jig until the rigid joints are formed and the unit is structurally self supporting.

Preferably, roof and floor panel members are progressively inserted parallel to the tie beam along the length of the longitudinal members and connected thereto through a sheet section that separates two spaced apart joists. The roof panel members are preferably positioned in alternate spacing to the wall panel members. A second end frame may be positioned at the second end of the unit.

According to an eleventh aspect, there is provided a method of building a building having a plurality of levels using a plurality of building unit assemblies according to the ninth aspect, the method including the steps of: lifting the building unit assemblies into position in the building so that each level of the building includes a predetermined number of units; connecting adjacent units to one another in each level; and connecting units in one level to corresponding units in at least one adjacent level that is vertically above or below the one level.

According to a twelfth aspect, the present invention provides a building unit assembly for stacking with other building unit assemblies to create a building, each building unit assembly having a plurality of prefabricated closed frame segments formed from two upright columns joined by an upper and a lower tie beam.

Preferably, the closed frame segments define the shape of the unit. The building unit assembly may include closed frame segments at the two ends of longitudinal members that define the internal length of the unit. Additional facades, such as a balcony, may project from one end of the unit, and may be integrated into an end closed frame segment. Additional closed frame segments may be spaced along the length of the unit. The building unit assemblies may include one or more amenity pods to create an internal room, e.g. a bathroom, kitchen, laundry or other utility room. Two closed frame segments may be spaced apart to define the position of the amenities pod. The pod may be inserted into the unit during assembly. The closed frame segments preferably support the weight of the units stacked above.

The closed frame segments preferably include tie plates built into the upper and lower ends of the columns. At least two closed frame segments in adjacent vertical and/or horizontal units align, such that the adjacent units can be connected together with a connection bracket.

The connection bracket preferably includes at least one pair of upper and lower aligned protrusions that are inserted into aligned apertures provided in the tie plates of a vertically aligned unit. The connection bracket may have two or four pairs of upper and lower aligned protrusions to connect horizontally adjacent units. Alternatively, for horizontally adjacent units, slots may be provided in the sides of the tie plates to allow for a bolted connection between abutting tie plates of horizontally adjacent units. The slots preferably lead from the apertures in the tie plates with a tapered section; such that suitably tapered nuts and bolts are provided that allow the tie plates to self align the adjacent closed frame segments upon tightening of the nut on the bolt.

The closed frame segments according to the twelfth aspect of the invention may be spaced apart along the length of the unit by horizontal elements, which may also be structural components: The horizontal elements may be elements that extend the full length of the unit with spaced apart attachment points for the closed frame segments, or may only extend between two adjacent closed frame segments. The horizontal elements could be floor formwork located at a lower end of the closed frame segments, e.g. between adjacent lower tie beams. The horizontal element could be floor formwork, with a first section located between adjacent lower tie beams and second sections located between adjacent upper tie beams. The first and/or second sections can include reinforcing bars. The second sections could include a channel with a reinforcing bar assembly, which may be precast into the channel with concrete. Advantageously the top of the reinforcing bar assembly extends above the height of the closed frame segments. In an alternative embodiment, the horizontal elements could be precast floor slabs and/or beams.

In the embodiments where floor formwork is used, the upper and/or lower tie beams could be channels and receive concrete during pouring of the floor. The upright columns may be hollow and also receive concrete during pouring.

According to a thirteenth aspect of the invention there is provided a method of assembling a building unit, including: providing a first prefabricated closed frame segment formed from two upright columns joined by an upper and a lower tie beam; positioning said first closed frame segment with respect to longitudinal members that extend perpendicularly to the tie beams; progressively assembling the building unit including positioning at least one other closed frame segment along the length of the longitudinal members using the positioned first closed frame segment as a datum.

In one embodiment, the longitudinal members are elements of a jig that is used to assemble the building unit assemblies. The first prefabricated closed frame segment is positioned in a predetermined location in the jig, with subsequent closed frame segments positioned along the longitudinal members of the jig at predetermined positioned that are measured with respect to the first closed frame segment. One or more horizontal elements are then positioned between adjacent closed frame segments and fastened between the closed frame segments to form a fully self supporting unit.

In another embodiment, the two longitudinal members are lower members of the unit that extend the length of the unit. Advantageously, after positioning the first prefabricated closed frame segment, floor panels are progressively positioned extending between the two lower longitudinal members. Additional closed frame segments are inserted in succession with the floor panels.

After the floor panels and closed frame segments are inserted, two upper longitudinal members may be inserted across the top of the corners of the closed frame segments, running parallel to the lower longitudinal members, thus defining the boundaries of the unit.

In some embodiments, roof panel members and side wall panel members are progressively positioned along the length of the longitudinal members.

The floor, roof and wall panels members are progressively connected to the longitudinal members, preferably by spot welding, toxing riveting or bolting.

According to a fourteenth aspect, there is provided a building unit assembly, including at least two structurally supporting closed frame segments, assembled according to the method of the thirteenth aspect of the present invention.

According to a fifteenth aspect, there is provided a formwork assembly for a structural surface of a building, said formwork assembly including at least one pair of building unit assemblies, each building unit assembly including: a first formwork portion defining a form to create a planar structure and a second formwork portion defining part of a form to create a beam structure; wherein the building unit assemblies are positioned to abut such that the second formwork portions of the abutting building unit assemblies correspond to form a formwork for creating a common beam or beam portion. The formwork assembly of the fifteenth aspect could be used in conjunction with any of the first to fifth and twelfth aspects in particular.

The building unit assemblies are structurally self supporting units that preferably include at least two prefabricated closed frame segments formed from two upright columns joined by an upper and a lower tie beam.

The second formwork portion may be positioned at the top of the building unit assemblies, extending across or between upper tie beams. In this embodiment, the second formwork is used to create a beam structure for the floor of units positioned above said building unit assemblies. Alternatively, the second formwork portion may be positioned at the bottom of the building unit assemblies, extending across or between lower tie beams. In this embodiment, the second formwork is used to create a beam structure for the floor of those units.

According to a sixteenth aspect, there is provided a building, the building including a plurality of building unit assemblies according to any one of the first to fifth or ninth or twelfth aspects of the invention, with infill material, such as concrete, being poured into the floor formwork creating the floors of the building.

Brief description of the drawings

The invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a building unit assembly according to a first embodiment of the present invention;

Figure 2 is a cross-sectional perspective end view of a wall panel member and an end view of several in a nested configuration;

Figure 3 is a perspective end view (showing partial length) of a roof panel member and an end view of several in a nested configuration; Figure 4 is a perspective end view (showing partial length) of a floor panel member and an end view of several in a nested configuration;

Figure 5 is a perspective end view (showing partial length) of a lower longitudinal member; Figure 6 is a perspective end view (showing partial length) of an upper longitudinal member;

Figure 7a is a cross-sectional perspective side view of a side wall of a building unit assembly according to a second embodiment of the present invention for constructing low rise buildings; Figure 7b is a cross-sectional perspective side view of a side wall of a building unit assembly according to a third embodiment of the present invention for constructing high rise buildings;

Figure 8a is a perspective view of two floor panel members positioned with respect to a lower longitudinal member; Figure 8b is a perspective view similar to Figure 8a with a wall panel member in position;

Figure 9 is an aerial view of a building unit assembly according to another embodiment of the present invention being stacked on top of another building unit assembly;

Figures 10a through 10e are perspective end views of a structurally supporting column, a lower tie beam, an upper tie beam, a base plate and a top plate, respectively, that form a closed frame segment;

Figure 11a is a cross-sectional end view of a building unit assembly according to an embodiment of the present invention; Figure 1 b is a cross-sectional side view of the building unit assembly shown in Figure 7a;

Figure 11c is a cross-sectional side view of the building unit assembly shown in Figure 7b; Figure 12 is a perspective view of a closed frame segment according an embodiment of the present invention;

Figure 13 is a cross-sectional end view of the closed frame segment of Figure 12;

Figure 14 is a perspective view of the closed frame segment of Figure 12 positioned with respect to two upper and two lower longitudinal members; Figure 15 is an exploded perspective view of a connection of two adjacent building unit assemblies;

Figure 16 are plan and section views of a top plate and base plate; Figure 17 is a top and side view of a connection plate;

Figure 18 is an exploded end view of a connection of two adjacent closed frame segments;

Figure 19 is an end view of four connected closed frame segments;

Figure 20 is a cross-sectional side view of a floor section of a building;

Figure 21 is a cross-sectional side view of a section of a building;

Figure 22 is a side view of floor formwork, with other components omitted; Figure 23 is a side view of the floor formwork of Figure 22 with infill material being poured; Figure 24 is a perspective view of a building unit assembly according to another embodiment of the present invention;

Figure 25 is an exploded perspective view of the building unit assembly of Figure 24;

Figure 26 is a perspective view of a building unit assembly according to another embodiment;

Figure 27 is a perspective view of a building unit assembly according to another embodiment;

Figure 28 is a perspective assembled view of a building unit assembly according to another embodiment; Figure 29 is a perspective exploded view of the building unit assembly of Figure 28;

Figure 30 is a perspective view of two building unit assemblies of Figure 24 being stacked;

Figure 31 is a perspective view of a plurality of building unit assemblies of Figure 24 being stacked to form a building; Figure 32 is a perspective view of a plurality of building unit assemblies of Figure 28 being stacked on top of a level that has had a continuous concrete floor poured;

Figure 33 is an end view of a tie plate, a top view of two adjacent tie plates with the closed frame segments out of alignment, a top view of the tie plates with the nut tightened and the closed frame segments secured and in alignment, an exploded side view of the fasteners and a perspective view of two adjacent tie plates according to one embodiment;

Figure 34 is a top view of an alternative connection plate, an end view of the connection plate, a side view of the connection plate and a perspective view of the connection plate Figure 35a is a cross-sectional view of the floor formwork of two adjacent units according to another embodiment;

Figure 35b is a view similar to Figure 35a with concrete being poured to form the floor;

Figure 36a is an exploded cross-sectional end view of upper and lower corners of two stacked units;

Figure 36b is a cross-sectional end view of the two stacked units of Figure 36a with concrete floor poured for the upper unit;

Figure 37a is an exploded cross-sectional side view of the two stacked units of Figure 36a; Figure 37b is a cross-sectional side view of the two stacked units of Figure 37a with concrete floor poured for the upper unit;

Figure 38a is an exploded cross-sectional end view of upper and lower corners of two stacked units and a cross-section end view of the two stacked units;

Figure 38b is an exploded cross-sectional end view of upper and lower corners of four stacked units and a cross-sectional end view of the four stacked units;

Figure 39a is a cross-sectional view through the poured floor between columns;

Figure 39b is a cross-sectional view through the poured floor at the columns;

Figure 40 is an aerial view of two building unit assemblies being assembled;

Figures 41a through to 41p show the successive assembly of a building unit assembly according to one embodiment of the present invention;

Figure 42 is an aerial view of a building unit assembly being craned into position to form a building; Figure 43 is a ground view of the underneath of the building unit assembly of Figure 42;

Figure 44 is an axonometric view of an assembly jig;

Figure 45 is a perspective end view of the assembly jig of Figure 44;

Figure 46 is an exploded perspective view of a portion of the assembly jig of Figure 44; Figure 47 is an end view of the assembly jig with a closed frame segment in position;

Figure 48 is a perspective view of a building unit assembly being constructed according to another embodiment of the invention;

Figure 49 is a perspective view of the building unit assembly of Figure 48 prior to transporting into position; Figure 50 is a perspective view of the building unit assembly of Figure 49 positioned on a truck for transport from the assembly site to the building site;

Figure 51 is a perspective view of the building unit assembly of Figure 49 being craned into position to create a building;

Figure 52 is a perspective view of a floor formwork according to another embodiment; Figure 53 is a perspective view of the floor formwork of Figure 52 with reinforcing mesh in position;

Figure 54 is a perspective view of the floor formwork of Figure 52 filled with concrete to create a floor slab for a building unit assembly;

Figure 55 is the floo^slab of Figure 54 with structurally supporting columns connected; Figure 56 is the building unit assembly of Figure 55 with walls added; and Figure 57 is the building unit assembly of Figure 56 with roof added. Detailed description of the embodiments

A building unit assembly 100 according to a first embodiment of the invention is shown in Figure 1 that is a prefabricated or preassembled unit that is fully self supporting. The unit 100 is able to be used to create a building of its own, be horizontally stacked to create a single storey building, or be stacked horizontally and vertically to create either a low rise or high rise building.

According to a first embodiment, the unit 100 includes two parallel lower longitudinal members 102 that are spaced apart the width of the unit, typically being around 4.5m or in the range of 3m to 5.5m, and run the entire internal length of the unit 100. The length of the unit is variable from job to job to suit the building design; the length illustrated is around 15m. Two upper parallel longitudinal members 104 are spaced in parallel alignment with the lower longitudinal members 102.

Spaced apart along the two sides of the unit 100 is a plurality of vertically extending panel members 106, illustrated as having a length of 3m to define a unit of 15m by 4.5m by 3m. The wall panel members 106 extend between, and are internal to, upper and lower longitudinal members 102, 104. The spaced apart wall panel members 106 create rectangular openings 107 therebetween, which may be used as a doorway. Alternatively a wall panel may be omitted or spacing may vary to create openings for doorways of the desired size. Extending perpendicular to and between the two upper longitudinal members 104 are spaced apart roof panel members 108. In the embodiment of Figure 1 , the roof panel members 108 are positioned in an alternating arrangement with the wall panel members 106, such that they alternate along the length of the upper longitudinal members 104. There are fourteen roof panels 108 and fourteen wall panels 106 illustrated along each side in Figure 1. Extending perpendicular to and between the two lower longitudinal members 102 are floor panel members 110, which butt up against each other to provide a continuous floor surface 112. It will be appreciated that in accordance with different embodiments of some of the aspects of the present invention, the wall panels and roof panels may also be abutted to create a continuous surface, or, in some aspects, omitted. In the embodiment shown in Figure 1 , which is in accordance with several aspects of the present invention, there is provided at either end of the unit 100 prefabricated closed frame segments 114, 116, the details of which will be discussed further below. Integrated into the first closed frame segment 114 is glazing and a balcony 118 that extends outwardly from the unit 100. Integrated into the second closed frame segment 116 is a wall with door aperture 120. Central to the unit 100 is an amenities pod 122 that is defined by two spaced apart closed frame segments 124, 126.

Details of the panel members will now be described with reference to Figures 2 to 8b, and can be defined as profiled steel sheeting panels. Vertically extending wall panel members 106 are shown in Figure 2 and include two spaced apart vertical studs 128 formed with a sheet section 130 extending therebetween. These wall panels 106 are formed by folding or roll forming from sheet steel such that the studs 128 are integrally formed with the sheet section 130. The studs 128 include a first portion 132 that extends generally perpendicularly, with a slight outward angle from the sheet section 130 to allow for nesting during transport and storage, as shown in Figure 2. The corner 134 has an inward bend to create a groove 135 that increases the strength of the panel 106, increases its ability to take vertical loads when vertically orientated and prevents binding when stacked. Flange sections 136 extend outwardly from the first portion 132 to create a top-hat configuration. The wall panels in the embodiment shown in Figure 2 have an overall width of 650mm, but may typically be in the range of 620-670mm. The sheet section is 508mm wide between the corner bends 134. The flange sections are each around 50mm wide, therefore the width from top of the corner bends 34 to the flange is 21mm. The depth of the wall panels 106 is around 75mm, and the sheet steel is around 1.6mm thick, but may be in the range of 1.2mm to 2.4mm. Whilst the first section 132 does not need to be perpendicular to either the flange sections 136 or the sheet section 130, the flange section 136 and the sheet section 130 do run in parallel. This creates two flat areas for the connection of inner and outer wall cladding. The centres of the two flange sections 136 are preferably spaced around 600mm apart. Additionally, each wall panel 106 is spaced apart from adjacent wall panels 106 by around 600mm from the centre of the flange sections 136. This results in a stud surface 136 spaced every 600mm along the side walls of the unit that meets the requirements for standard plaster board fixing. The sheet section 130 provides a flat surface for external cladding. With two studs 128 being integrally formed with a sheet section 130, at least half the number of components is required to meet the spacing requirements of plaster board. As can be seen in Figure 2, the sheet sections 130 may extend further than the studs 128 in the length, creating a flat end section 178, which assists in connection as discussed further below.

Figure 3 shows an embodiment of the roof panels 108, which are of a similar top-hat configuration as the wall panels, having a sheet section 140 separating two spaced apart joists 138. The first portions 142 are slightly longer than the first portions 132 in the wall panels to create an overall greater depth of 100mm, with the width being the same at 650mm. The sheet section is 504mm wide with the flange sections being 50mm wide, therefore the width from the top of the corner bends 144 to the flange is 23mm.

The floor panel members 110 include two joists 148 that depend from a central sheet section 150. The joists 158 include two first portions 152 each depending from a corner 154. At the end of the first portions are outwardly extending flanges 156 with a downward portion 157 to stiffen the structure as it takes downward loading. The sheet section 150 and first portions 152 extend further than the flanges 156 to create areas 176 for affixing to the second plate 162 of lower longitudinal member 102 (see Figure 8a). In the sheet section 150 there are two outwardly opening grooves 155 spaced inwardly from the corners 154. It will be appreciated that the grooves may be inwardly opening. In various embodiments, the floor panel members 110 create a continuous floor surface 112 creating a floor formwork for the pouring of infill material. The grooves 155 are created from undercut bends in the sheet section; such that infill material 161 can flow into the grooves 155 and when set form a positive engagement between the floor formwork 112 and the infill material 161. The first portions 152 are angled slightly outwardly to allow for nesting, as shown in Figure 4, with the grooves 155 preventing the panel members from locking together during nesting.

The grooves 155 illustrated are inward of the corners 154 by 70mm such that the central sheet section 150 is 370mm wide between the grooves 155. The length of the first portions 152 is such that the resulting overall depth is 175mm, and the flange sections 156 are 25mm wide with the downward portion 157 being 20mm. The overall width of the floor panel member is 600mm. It will be appreciated that these dimensions are adaptable for the specific requirements of a job. Figure 5 shows the cross-sectional shape of the lower longitudinal members 102, which are L-section channels and comprise a first plate 160 and a perpendicular second plate 162, being formed by folding sheet steel of 3-6mm thickness. First plate 160 is wider at 225mm than second plate 162 at 150mm. Figure 6 shows the cross-sectional shape of the upper longitudinal members 104, again having a first plate 164 and a second plate 166, with the first plate 164 being slightly wider at 150mm than the second plate 166 at 100mm.

Assembly of one embodiment of a building unit assembly is shown in Figure 7a, which is applicable for single storey buildings or low rise buildings of up to four storeys. As shown, a first end of the unit is bounded by a vertically extending column 170 that may or may not be structurally supporting depending on the application. Columns 170 are made from 3mm thick steel in the illustrated embodiment. In the embodiment shown in Figure 7a, the panel members 106 are structurally supporting and can withstand the vertical loads of the one to three units stacked on top, becoming internal studs that form the load bearing structure of the building. Structurally supporting columns are required for buildings over four units high (this is shown in Figure 7b). The columns 170 are joined by upper and lower tie beams 172, 174. Both the columns and the tie beams are C-channels. The column 170 sits in the lower longitudinal member 102, with second plate 162 lying horizontally. At the upper end of the columns 170 is the upper longitudinal member 104, with the first plate 164 lying horizontally. The longitudinal members 02, 104 extend perpendicular to the tie beams 172, 174.

For high rise buildings, a closed frame segment 114 may be incorporated into the assembly, as shown in Figure 7b and discussed further below. According to certain aspects of the invention, the closed frame segment can be utilised without the longitudinal members or panel members. In the embodiment shown in Figures 8a and 8b, the end of the floor panels 110 slide into the lower longitudinal members 102, locking into the corner. This provides two areas 176 where the flange sections 156 engage against the second plate 162. The floor panels 110 abut against each other to create a continuous floor 112 that can become formwork for infill material such as concrete or gypsum. As shown in Figure 11c, the downward portions 157 of adjacent panels may be joined together and create channels 167 into which infill material such as concrete or gypsum flows, with a layer of infill extending over the sheet sections. The top-hat configuration creates a void 169 underneath the floor, reducing the amount of concrete required and provides space for underfloor wiring or heating. The floor panel members 110 of Figures 4, 8a and 8b differ to those shown in Figures 7a, 7b, 11b and 11c. In the latter construction, additional inwardly opening grooves 155a are provided given an additional undercut for the infill material to lock into.

Alternatively, in some aspects, plywood panels could be attached to the sheet sections 50 or the panel members could be inserted in an inverted orientation where the downward portions 157 are omitted and the plywood is affixed to the flange sections 156.

Figures 7a and 8b show the connection of the wall panels 106 that sit on the lower longitudinal members 102 and are positioned to slot between the roof panels 108. The projecting area 178 lies flat against the outer surface of first plate 160 where the two components can be connected together, preferably by three spot welds 180 spaced along the width of the sheet section 130 (as shown in Figure 8b). The sheet section 130 connected in this way creates a rigid joint, being a joint that is capable of resisting bending movement, due to the connection at at least two spaced locations. A narrower sheet section with only one spot weld or rivet would result in a non-rigid joint that was unable to resist movement under lateral loads. The sheet section 130 creates a bracing element for the two studs, which together with the rigid joint, creates a Vierendeel truss construction. The roof panels 108 are inserted from underneath (see Figures 7a and 7b) such that their sheet sections 140 abut against the first plate 164 of the upper longitudinal members 104. Spot welds or rivets are used to connect them together.

Figures 7a and 7b show how the roof and floor panel's joists 138, 148 align with the wall studs 128, with the wall panels 110 typically being in offset arrangement to the roof panels 108 (best shown in Figure 1). The alignment of the studs 128 and joists 138, 148 creates rigid rings around the unit 100 increasing the unit's ability to withstand lateral and compressive loads. Figures 11a and 11b show cross-sections through the side and end of the unit further illustrating how the panels 106, 108, 110 interact with the longitudinal members 102, 104 and the columns 170 and tie beams 172, 174.

An alternative embodiment of the first aspect of the invention is shown in Figure 9, where the building unit assemblies are stacked for low rise buildings, such that there are no additional structurally supporting columns. The vertically extending panel members 106 with vertical studs 128 and sheet section 130 are load bearing and support the weight of the units above by spreading the load across the length with the longitudinal members 104. According to various embodiments, the addition of structurally supporting columns can make units suitable for high rise constructions.

The embodiment illustrated in Figures 12 through 21 relate to a unit 100 that can be used for high rise buildings, as it includes structurally supporting columns 182 that are integrated into prefabricated closed frame segments 114. The closed frame segment 114 is prefabricated (typically off-site, but may be done onsite prior to assembly) as a rectangular ring (of height 3m and width 4.5m, see Figures 12 and 13) and is illustrated in this embodiment with two spaced apart parallel columns 182 being of rectangular tubular form (of 150x150mm of 5mm thick steel, Figure 10a) joined together by a lower tie beam 184 of rectangular tubular form (of 150x150mm of 5mm thick steel, Figure 10b) and an upper tie beam 186 also of rectangular tubular form (of 100x150mm of 5mm thick steel, Figure 10c). Integrated into the closed frame segment 114 are tie plates (of 240x150mm of 25mm thick steel) being two upper top plates 188 and two base plates 190 that sit at the top and bottom of the columns 182 and extend into cut out sections 192 in the tie beams 184, 186. As shown in Figure 14, the closed frame segments 114 define the shape of the unit, with the longitudinal members 102, 104 being positioned at their corners and projecting perpendicularly to the tie beams 184, 186. These closed frame segments are internal to the unit 100 and form the load bearing structure of the building. Alternative embodiments of the closed frame segments are shown in Figures 24-32 and 48-56, to be described further below.

When building unit assemblies 100 are stacked upon each other, at least two closed frame segments 114 are aligned. Figure 15 shows an exploded view of two units being stacked, with the tie beams 184, 186 being omitted to improve visibility of the other components. The longitudinal members 102, 104 include aligned apertures 194 in their horizontally oriented plates 162, 164. These apertures 194 align with apertures 196 provided in the tie plates 188, 190. A connection bracket 198 is used to join adjacent units together. The connection bracket 198 includes at least two upper protrusions 200 and two lower protrusions 202, being aligned, such that one upper protrusion 200 projects through the aperture 194 in the lower longitudinal member 102 and into the aperture 196 in the base plate 190. The lower protrusion 202 projects through the aperture 194 in the upper longitudinal member 104 and into the aperture 196 in the top plate 188. Fasteners 204 are used to secure the connection bracket 198 to the tie plates 188, 190. Additional fasteners 206 secure from one tie plate 188, through connection bracket 198, to the other tie plate 190. As shown in Figure 19, the one connection bracket 198 can join adjacent vertical and horizontal units.

Figures 20-33b illustrate alternative embodiments, where floor formwork is integrated into the building unit assembly 100. As can be seen from Figure 21 , the vertical first plate 160 of the lower longitudinal members 102 form the side walls that extend above the upper surface of the sheet section 150 of the floor panel members 110 to create the side of the formwork for the pouring of infill 161. As seen in Figures 20 and 21 , when the formwork 112 is in position it creates voids 169 which are not penetrable by the infill 161. As the upper surfaces 150 are horizontal, once craned into position (see Figures 22 and 23) the formwork allows the infill 161 to flow over the surface, into the channels 167 and self level to create a horizontal surface. The panels 110 take the weight of the wet infill 161.

In the embodiment shown in Figure 21 , lower longitudinal members 102 create the edge of the formwork. Therefore, as the infill 161 is poured, it casts-in the lower longitudinal members 102 and any internal structurally supporting columns, locking them to the formwork 112 and floor 161; this includes the lower portion 178 of wall panel members 106. Once set, the loading applied to the floor 161 is taken through the infill and filled channels 167.

According to this embodiment, a building unit assembly 100 is provided that is structurally self supporting and once positioned can be filled with infill material without having to subsequently erect formwork or remove it after the floors are formed. The top- hat panel configuration to create the formwork creates voids to reduce the amount of infill required, and allows for the on-site assembly by the progressive insertion of the plurality of panels to any length required by the unit. Alternative embodiments of a number of aspects of the present invention are shown in Figures 24 through 39b. A building unit assembly 400 is shown that includes a plurality of prefabricated closed frame segments 414, which are formed from two upright columns 482 joined by an upper tie beam 484 and a lower tie beam 486. These prefabricated closed frame segments 414 are spaced apart along the length of the unit 400 by horizontal elements. In the embodiment illustrated in Figures 24 and 25, the horizontal spacing elements are sections of floor formwork 403 that extend between adjacent lower tie beams 486, and upper beam formwork 405 that extend between adjacent upper tie beams 484.

Referring to Figures 28a through 39b, the upper beam formwork 405 is illustrated as a channel 407 for receiving longitudinal sections of reinforcing bars 409 that form a cage structure. The reinforcing bar assembly 409 sits within the channel 407 and can be set in place by pre-pouring a thin layer of concrete 411 around the base of the reinforcing bar assembly 409 fully or partly filling the channel 407 either prior to assembly or during assembly on the ground. This is shown in more detail in Figures 35a, 35b and 36a. These reinforcing bar assembly 409 extend above the height of the upper tie beams 484, as shown in Figure 36a. The floor formwork 403 is inset laterally from the upright columns 482 and do not meet the floor formwork of a horizontally adjacent module in use. This spacing creates voids 483. When another unit 400a is stacked on top of the first unit 400, as shown in Figure 36b, the reinforcing bar assemblies 409 of the lower unit extend into the voids 483a of the upper unit and become part of the formwork for the upper unit's floor, sitting flush with the top surface of the formwork 403. The channels 407 complete the bottom of the formwork and together define a beam. When poured (Figure 35b and 36b) the concrete for the upper floor 412a sets around the reinforcing wire 409, further locking the upper and lower units 400a, 400 together. The adjacent reinforcing bar assemblies 409 (see Figures 35b) create a single unified reinforcing beam 417 for the floor (see Figure 39a). The reinforcing bar assemblies 409 do not extend over the top of the closed frame segments 414 so that the closed frame segment 414a of the upper unit can sit flat on top of the lower closed frame segment 414, allowing them to be connected by connection brackets 498 (shown best in Figures 24 and 30). As described in relation to earlier embodiments, the connection brackets 498 include upper and lower protrusions 500, 502 (see Figures 33 and 34) that extend out from a central plate and engage in apertures 496 in the tie plates 488, 490 in the closed frame segments 414. A recessed portion 499 is provided in the underside of the closed frame segment 414 to accommodate the depth the connection bracket 498.

One of the advantages of this construction is that many different types of flooring can be utilised with these units. As shown in Figure 27, precast concrete slabs 415 can be utilised for the floor, with each being a horizontal element extending between closed frame segments 4.14. The pouring of concrete about the reinforcing bar assemblies 409 both lock the floors together and allow for any tolerance issues with the precast slabs 415 or formwork where customised formwork has not been used in the assembly.

Connection of adjacent horizontal units 400 is achieved through slots 501 in the sides of the tie plates 488. The slots 501 lead from the apertures 496 with a tapered section 503. A bolt 505 is used, onto which a tapered spacer 507 is placed; with the spacer's taper matching the taper direction of the tapered section 503 (see Figure 33). Qnce the bolt 505 is pushed through the two slots 501 , a tapered nut 509 is threaded onto the end of the bold 505. As shown in Figure 33, the tie plates (and therefore closed frame segments 414 and units 400) are out of alignment, with the width of the slot allowing for the bolt to sit at an angle. When the nut 509 is tightened on the bolt 505, the corresponding tapers on the spacer 507 and the nut 509 slide into the tapered sections 503, drawing the two tie plates 488 together and into alignment.

Figure 31 shows a plurality of units being stacked together and joined horizontally to form a building. As can be seen, each unit 400 is a volumetric structural unit, which is self supporting after assembly on the ground. Assembly could be achieved either on site or off-site. Once assembled, the units 400 can be lifted by crane into position. Figure 31 shows the building being constructed before pouring the concrete floors, however, as shown in Figure 32, it is more common for a first floor to be constructed and the concrete poured for the floor before or whilst the second floor units 400a are being craned into position and connected together. The second floor units 400a then have their concrete poured; see Figures 35a, 35b, which shows how the reinforcing bar assemblies 409 from the unit 400 below with pre-poured thin layer of concrete 411 become part of the formwork 412 for the floor above. Additional floor reinforcing mesh

413 is used, which can be inserted before pouring or during assembly of the units 400, see Figure 29. Figure 31 illustrates the edge construction 401 of the formwork of a unit sitting at the outer edge of the building. The edge construction 401 defines the borders of trie floor being poured.

The upper and lower tie beams 484, 486 of the prefabricated closed frame segments

414 are constructed as channels in the embodiments illustrated in Figures 24 to 32. The columns 482 may also be constructed as a hollow tubular member, such that when the floor of an upper unit 400a is poured, concrete flows into the lower tie beam 486a of the upper unit 400a (see Figure 37b) and through apertures spaced along the bottom surface of the lower tie beam 486a into the channel of the upper tie beam 484 of the lower unit 400. The concrete then flows along the channel of the upper tie beam 484 and into the upright columns 482, flowing underneath the upper tie plates 488. This concrete flow occurs for each level as constructed, such that the pouring of the upper level floor fills the upper tie beam 484 and columns 482 of the lower unit 400. Figures 39a and 39b show end and side cross-sectional views through the finished structural construction of the building levels. The prefabricated closed frame segments 414 are still visible in the construction and form structurally supporting elements for the building together with the floor slabs.

An alternative building unit assembly 400 is shown in Figure 26, which is constructed from spaced apart closed frame segments 414, spaced apart by floor formwork sections 403 that include side channels 419. Header rails 421 are then inserted between and welded to the closed frame segments 414 to complete the construction of the structurally self supporting building unit assembly 400. The side channels 419 can become part of the floor formwork and filled with concrete. Alternatively, the channels 419 can receive wall panels or shear walls to be infilled with concrete once lifted onto the building. Where the building unit assembly 400 is to be located at an edge of the building, the channels 419 may be used to receive the building facade.

The method of assembling the units 100 according to one embodiment will now be described, as illustrated in Figures 40 through 47, which illustrate one embodiment that includes closed frame segments. As can be seen from Figures 40 and 44 to 47, a jig 110 could be used to provide alignment locations for the upper and lower longitudinal members. Figures 41a and 41b show how a first prefabricated closed frame segment 114 is positioned with respect to two lower longitudinal members 102. As shown in Figure 41c, the first closed frame segment 114 may be pre-fitted with a facade, such as glazing and a balcony 118.

The floor panel members 110 are then successively laid, abutting against each other, as shown in Figures 41 d to 41 f to create a solid floor surface 112, which can become a floor formwork. Second and subsequent closed frame segments may be inserted along the length of the longitudinal members 102, with the positioned first closed frame segment 114 being used as a datum to ensure accurate alignment of all components of the unit. As shown in Figure 41g, an amenities pod 122 may be constructed from two spaced apart closed frame segments 124, 126, with wall, floor and roof cladding 125 being used to create a room, such as a bathroom. The amenities pod could be fully assembled and fitted out prior to installation in the unit. As the closed frame segments 114, 124, 126 are of uniform predetermined dimensions, the amenities pod 122 simply slots into place between" the lower longitudinal members 102 against a floor panel 110. Subsequent floor panels 100 are then progressively slotted in to complete the floor. A second closed frame segment T16, which includes an end wall with door opening 120 is positioned at the end of the longitudinal members 102, defining the length of the unit 100 (see Figure 41 i). Any number of other closed frame segments can be positioned between the first and second closed frame sections 114, 116.

As shown in Figure 41j, the two upper longitudinal members 104 are positioned, extending between the first closed frame segment 114 and the second closed frame segment 116. Roof panel members 108 are then progressively inserted in between the upper longitudinal members 104 to create the roof (Figure 41m). Wall panel members 106 are then aligned on the two sides and progressively inserted and affixed by spot welding robots 112 (Figures 41 n to 41 p) that progressively move along the length of the unit. It will be appreciated that the unit could be manually assembled.

A building unit assembly 100 is produced that is structurally self supporting such that it may be lifted into position by a crane, see Figures 42 and 43. The method of manufacturing allows for assembly to occur on site, whereby an assembly plant can be set up either on site or in close proximity, reducing or eliminating the transport costs associated with fully assembled units. The folding of the sheet steel may also be conducted on site. An assembly jig 600, similar to that shown in Figure 40, is illustrated in Figures 44 through 47. The assembly jig 600 includes two spaced apart sides 602, 604, each having an upper level 606, 608 and a lower level 610, 612. The two sides 602, 604 are spaced apart by lower spacing elements 614 and at least one overhead gantry crane 616 with hooks 618 arranged to travel along the cross beams 620, with the cross beams 620 able to travel along the side rails 622. This jig arrangement allows for successive assembly of the units. Along the lower levels 610, 612 are longitudinal members 624 that are raised by frames 626. Spaced along the longitudinal member 624 are support plates 628 that are positioned prior to assembly at the desired locations for the closed frame segments 414 for the unit's 400 requirements. They can be individually adjusted, such that the specific requirements for each unit can be preset. Similarly, once preset, accurate positioning of closed frame segments in subsequent assembled units will be achieved to ensure alignment of closed frame segments in vertically and horizontally adjacent units during construction of a building. Once the support plates 628 are positioned and locked in place, clamping devices 630 (see Figure 47) can be positioned on the support plates 628 and connected to the side frames 632. A first closed frame segment 11^*4 can then be positioned in the clamp 630, with clamping elements 634 locking over the top of the closed frame segments 114. A second closed frame segment (not shown) is then positioned in a subsequent clamping device (not shown) with the position being taken using the first closed frame segment 1 4 as a datum. Horizontal elements, such as floor formwork 103 and upper beam formwork 105 are positioned between and attached to adjacent spaced closed frame segments. This process is repeated until the unit 100 is fully assembled as a volumetric self supporting structure element, ready to be craned into position to form a building or into a storage area prior to positioning. Another alternative building unit assembly 800 is shown in Figures 48 to 51 , which utilises a precast floor slab 812 that extends the full length of the assembly 800. The slab may include cut out sections 813 at spaced locations along the edge of the slab 812 and at the corners for receiving the lower ends 815 of upright columns 882. Upright columns 882 are joined by an upper tie beam 886 to create a structurally supporting column assemblies 814 being of an arch nature. The lower ends 815 may either be affixed, by bolting or welding, or may be cast in place when the slab 812 is poured. The column assemblies 814 together with the slab 812 define the shape of the structure. At least one end of the slab may include a stepped down section 817 adapted to receive a facade, such as glazing 818, as shown in Figure 49. Upper longitudinal members 804 are positioned and affixed across the top corners of the tie beam 886. Components and material may be stacked in the unit for transport, to be fitted out once in position. As can be seen from Figure 50, a building unit assembly 800 can be placed on the tray of a truck and transported from the assembly location to the building site, where it can be craned into position, as shown in Figure 51. Another alternative building unit assembly 900 is shown in Figures 52 to 56, which is constructed by creating a floor slab 961 using a floor formwork 9 2 having at least two tie beams 984 extending across the width of the floor formwork 912. These tie beams 984 are linked by longitudinal members 902. As can be seen in Figure 53, the floor formwork 912 is fitted out with internal reinforcing mesh 913 and relevant plumbing and is then filled with concrete to form slab 961. Structurally supporting column assemblies 914 are provided, that may consist of two upright columns 982 and an upper tie beam 986. The assembly 914 may include an additional lower tie beam; but in the embodiment illustrated the lower tie beam 984 affixes to the lower ends 915 of the columns 982 to create a closed frame segment of rectangular construction. Upper longitudinal members 904 are then added with wall panels 906 of any suitable construction to form the building unit assembly 900 that is ready for incorporation into a building.

The various aspects and embodiments of the present invention provide building unit assemblies that are structurally self supporting with reduced components and reduced labour costs, which can be assembled on site. The assembly time for these building units is greatly less than known systems, which assists in reducing the overall build time for a building. A building unit assembly made in accordance with the various aspects of the present invention is a rectilinear box frame which is structurally independent and self supporting in terms of its own weight and the live loads it will carry, and is also able to, when stacked, carry the load of the unit(s) above. Flexibility in the building design is provided, as the size of the unit is dictated by the dimensions of the components, not by transport restrictions. The longitudinal members may be shorter or longer and adapted to the need. Indeed, a building can be designed utilising different length units in its constructions, with the same equipment being used to assemble units of different lengths. Other benefits of the invention include greater flexibility to meet original architectural intent/design compared to known modular alternatives, and the ability to achieve very high levels of accuracy/precision compared with in situ assembly and traditional construction techniques. It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.

Claims

1. A self supporting building unit assembly for use in constructing a building, including floor formwork and a plurality of structurally supporting columns for attachment to a vertically adjacent building unit assembly; whereby the floor formwork is able to receive and support a poured infill material.

2. A self supporting building unit assembly for use in constructing a building, whereby the building unit assembly includes floor formwork and at least two closed frame segments formed from two upright columns joined by upper and lower tie beams, whereby the floor formwork is able to receive and support a poured infill material and whereby the closed frame segments provide structural support to the constructed building.

3. A self supporting building unit assembly having structure defining a rectilinear box including floor formwork and a plurality of structurally supporting columns or studs, wherein the floor formwork is able to receive and support a poured infill material, and whereby the infill material is poured about the feet of the columns or studs.

4. A self supporting building unit assembly according to claim 3, wherein two studs are formed integrally with a sheet-section extending therebetween to create a panel member.

5. A self supporting building unit assembly including floor formwork and a plurality of vertically extending panel members including two spaced apart vertical studs formed with a sheet section extending therebetween, whereby the floor formwork is able to receive and support a poured infill material and whereby the studs are capable of structurally supporting another building unit assembly placed on top.

6. A self supporting building unit assembly according to claim 4 or 5, wherein the vertically extending panel members are spaced apart along opposing side walls of the building unit assembly creating spaced rectangular openings or voids.

7. A self supporting building unit assembly according to any one of the preceding claims, wherein the floor formwork comprises a plurality of adjacent floor panel members.

8. A self supporting building unit assembly according to claim 7, wherein the floor panel members abut against each other to create a continuous surface.

9. A self supporting^* building unit assembly including floor formwork created from a plurality of panel members that abut or join together, whereby the upper surface of the formwork is substantially level such that the subsequent poured infill material self levels.

10. A self supporting building unit assembly according to any one of the preceding claims, wherein the floor panel members include a sheet section with two depending wall sections to create a top-hat configuration.

11. A self supporting building unit assembly according to claim 10, wherein the depending walls include outwardly extending flanges.

12. A self supporting building unit assembly according to claim 10 or 11, wherein the sheet section includes at least one undercut bends in the sheet section, to create a lateral groove or grooves into which the infill material can flow and set to form a positive engagement between the floor formwork and the infill material.

13. A self supporting building unit assembly according to any one of claims 10 to 12, wherein the depending wall sections create a channel between two abutting panel members.

14. A self supporting building unit assembly according to any one of claims 10 to 13, whereby a void is created under the sheet section between the two wall sections into which the infill material cannot penetrate.

15. A self supporting building unit assembly according to any one of the preceding claims, wherein the infill material casts-in the vertical columns, closed frame segments and/or vertical panel members and locks them to the floor and floor formwork.

16. A self supporting building unit assembly according to claim 1 , 2 or 9, further including at least two opposing side walls including a plurality of vertically extending panel members spaced apart from each other, the panel members including two spaced apart vertical studs formed with a sheet section extending therebetween, whereby the panel members are connected through the sheet section at their upper and lower ends to longitudinal members running the length of the side walls of the building unit assembly, such that a rigid joint is created and the building unit assembly is structurally self supporting.

17. A self supporting building unit assembly according to claim 16, wherein the two spaced apart vertical studs are integrally formed with the sheet section.

18. A self supporting building unit assembly having at least two opposing side walls including a plurality of vertically extending panel members spaced apart from each other, the panel members including two spaced apart vertical studs formed with a sheet section extending therebetween, whereby the panel members are connected through the sheet section at their upper and lower ends to longitudinal members running the length of the side walls of the building unit assembly, such that a rigid joint is created and the building unit assembly is structurally self supporting.

19. A self supporting building unit assembly according to claim 18, wherein the two spaced apart vertical studs are integrally formed with a sheet section. 20. A self supporting building unit assembly according to claim 16, 18 or 19, wherein the studs include at least a first portion extending substantially perpendicularly to the sheet section, and at least one flange section extending from the first portion, substantially perpendicularly, such that the flange section is parallel to the sheet section. 2 . A self supporting building unit assembly according to claim 20, wherein the first portion is inclined outwardly from the sheet section to the flange, such that a plurality of top-hat shaped panel members may be stacked in a nested configuration.

22. A self supporting building unit assembly according to claim 20 or 21 , wherein the distance between the centres of the two flange sections is in the range of 350mm to 750mm.

23. A self supporting building unit assembly according to any one of claims 20 to 22, wherein, when positioned in the building unit assembly, the first portion extends inwardly from the sheet section, with the sheet section forming the outer wall of the building unit assembly.

24. A self supporting building unit assembly according to any one of claims 18 to 23, further including a plurality of structurally supporting columns for supporting another building unit assembly placed on top.

25. A self supporting building unit assembly according to any one of claims 18 to 23, further includeing floor panel members extending horizontally between two lower longitudinal members.

26. A self supporting building unit assembly according to any one of the preceding claims, further including roof panel members extending horizontally between two upper longitudinal members.

27. A self supporting building unit assembly according to any one of claims 8 to 25, further including roof panel members extending horizontally, wherein the vertical studs of the wall panel members align with corresponding roof and floor horizontal joists or side walls of the floor panel members to create a rigid loop around the building unit assembly.

28. A self supporting building unit assembly according to any one of claims 18 to 25 and 27, wherein the vertically extending panel members support the weight of another building unit assembly placed on top. 29. A self supporting building unit assembly according to any one of claims 18 to 25, wherein the sheet sections are connected at two or more points along the width of the sheet section to create a rigid joint. O 2014/056024

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30. A self supporting building unit assembly for stacking with other building unit assemblies to create a building, each building unit assembly having a plurality of prefabricated closed frame segments formed from two upright columns joined by an upper and a lower tie beam. 31. A self supporting building unit assembly according to claim 30, wherein the closed frame segments define the shape of the unit.

32. A self supporting building unit assembly according to claim 30 or 31 , wherein facades may be integrated into an end closed frame segment.

33. A self supporting building unit assembly according to claim 30, 31 or 32, wherein two closed frame segments are spaced apart to define the position of an amenities pod, which is inserted into the unit during assembly.

34. A self supporting building unit assembly according to any one of claims 30 to 33, whereby the closed frame segments support the weight of the units stacked above.

35. A self supporting building unit assembly according to any one of the preceding claims, wherein structurally supporting columns include tie plates built into the upper and lower ends of the columns, such that the adjacent units can be connected together.

36. A self supporting building unit assembly according to claim 35, wherein a connection bracket can be used to connect the adjacent units together, the connection bracket includeing at least one pair of upper and lower aligned protrusions that are inserted into aligned apertures provided in the tie plates of a vertically aligned unit.

37. A self supporting building unit assembly according to claim 36, wherein the connection bracket has two or four pairs of upper and lower aligned protrusions to connect horizontally adjacent units.

38. A self supporting building unit assembly according to claim 35, wherein, for horizontally adjacent units, slots are provided in the sides of the tie plates to allow for a bolted connection between abutting tie plates of horizontally adjacent units.

39. A self supporting building unit assembly according to claim 38, wherein the slots lead from the apertures in the tie plates with a tapered section, such that suitably tapered nuts and bolts are provided that allow the tie plates to self align the adjacent closed frame segments upon tightening of the nut on the bolt. 40. A self supporting building unit assembly according to claim 30, wherein closed frame segments are spaced apart along the length of the unit by horizontal structural components.

41. A self supporting building unit assembly according to claim 40, wherein the horizontal elements are floor formwork located between adjacent lower tie beams. 42. A self supporting building unit assembly according to claim 40, wherein the horizontal elements are floor formwork, with a first section located between adjacent lower tie beams and second sections located between adjacent upper tie beams.

43. A self supporting building unit assembly according to claim 42, wherein the first and/or second sections include reinforcing bars. 44. A self supporting building unit assembly according to claim 42, wherein the second sections include a channel with a reinforcing bar assembly.

45. A self supporting building unit assembly according to claim 44, wherein the reinforcing bar assembly is precast into the channel with concrete.

46. A self supporting building unit assembly according to claim 44 or 45, wherein the top of the reinforcing bar assembly extends above the height of the closed frame segments.

47. A self supporting building unit assembly according to any one of the preceding claims, wherein where floor formwork is used, the upper and/or lower tie beams are channels that receive concrete during pouring of the floor.

48. A self supporting building unit assembly according to any one of the preceding claims, wherein upright columns are hollow and receive concrete during pouring.

49. A formwork assembly for a structural surface of a building, said formwork assembly including at least one pair of building unit assemblies, each building unit assembly including: a first formwork portion defining a form to create a planar structure and a second formwork portion defining part of a form to create a beam structure; wherein the building unit assemblies are positioned to abut such that the second formwork portions of the abutting building unit assemblies correspond to form a formwork for creating a common beam or beam portion.

50. A formwork assembly according to claim 49, wherein the building unit assemblies are structurally self supporting units that include at least two prefabricated closed frame segments formed from two upright columns joined by an upper and a lower tie beam.

51. A formwork assembly according to claim 49 or 50, wherein the second formwork portion is positioned at the top of the building unit assemblies, extending across or between upper tie beams.

52. A formwork assembly according to claim 51, wherein the second formwork portion is used to create a beam structure for the floor of units positioned above said building unit assemblies. 53. A formwork assembly according to claim 49 or 50, wherein the second formwork potion is positioned at the bottom of the building unit assemblies, extending across or between lower tie beams.

54. A formwork assembly according to claim 53, wherein the second formwork is used to create a beam structure for the floor of those units.

55. A formwork assembly according to any one of claims 49 to 54, used in conjunction with any of the self supporting building unit assemblies of claims 1 to 48.

56. A method of assembling a building unit assembly for use in constructing a building, including: positioning a floor formwork having at least two tie beams extending across the width of the floor formwork; pouring infill material into the floor formwork; positioning at least two structurally supporting column assemblies including two upright columns joined by an upper tie beam; affixing respective column assemblies to a respective formwork tie beam to create a closed frame segment such that the building unit assembly is structurally self supporting.

57. A method of building a building using a plurality of building unit assembles according to claim 1, wherein the infill material has been poured into the floor formwork during assembly of the building unit assemblies, the method including the steps of: lifting the building unit assemblies into position in the building so that each level of the building includes a predetermined number of units; connecting adjacent units to one another in each level; and connecting units in one level to corresponding units in at least one adjacent level that is vertically above or below the one level.

58. A method of building a building using a plurality of building unit assemblies according to any one of claims 1 to 48, the method including the steps of: lifting the building unit assemblies into position in the building to create at least one level of a predetermined number of units; connecting adjacent units to one another in each level; pouring infill material into the floor formwork of each unit to create the floor(s) of the building.

59. A method of assembling a building unit, including: positioning an end frame, having two upright columns joined by at least one tie beam, with respect to two longitudinal members that extend perpendicularly to the tie beam; progressively assembling the building unit by positioning a plurality of vertically extending panel members in spaced apart relation along the two longitudinal members, the panel members including two spaced apart vertical studs formed with a sheet section extending therebetween; connecting the panel members through the sheet section at their upper and lower ends to the longitudinal members, such that a rigid joint is created and the building unit assembly is structurally self supporting.

60. A method according to claim 59, wherein the longitudinal members are held in a jig until the rigid joints are formed and the unit is structurally self supporting.

61. A method according to claim 59 or 60, wherein roof and floor panel members are progressively inserted parallel to the tie beam along the length of the longitudinal members and connected thereto through a sheet section that separates two spaced apart joists.

62. A method according to claim 61 , wherein the roof panel members are positioned in alternate spacing to the wall panel members.

63. A method according to any one of claims 59 to 62, wherein a second end frame is positioned at the second end of the unit.

64. A method of building a building having a plurality of levels using a plurality of building unit assemblies according to any one of claims 18 to 29, the method including the steps of: lifting the building unit assemblies into position in the building so that each level of the building includes a predetermined number of units; connecting adjacent units to one another in each level; and connecting units in one level to corresponding units in at least one adjacent level that is vertically above or below the one level.

65. A method of assembling a building unit, including: providing a first prefabricated closed frame segment formed from two upright columns joined by an upper and a lower tie beam; positioning said first closed frame segment with respect longitudinal members that extend perpendicularly to the tie beams; progressively assembling the building unit including positioning at least one other closed frame segment along the length of the longitudinal members using the positioned first closed frame segment as a datum.

66. A method according to claim 65, wherein the longitudinal members are elements of a jig that is used to assemble the building unit assemblies.

67. A method according to claim 66, wherein the first prefabricated closed frame segment is positioned in a predetermined location in the jig, with subsequent closed frame segments positioned along the longitudinal members of the jig at predetermined positioned that are measured with respect to the first closed frame segment.

68. A method according to claim 65, wherein the two longitudinal members arelower members of the unit that extend the length of the unit.

69. A method according to claim 68, whereby, after positioning the first prefabricated closed frame segment, floor panels are progressively positioned extending between the two lower longitudinal members.

70. A method according to claim 69, wherein additional closed frame segments are inserted in succession with the floor panels. 71. A structurally self supporting building unit assembly, including at least two structurally supporting closed frame segments, assembled according to the method of any one of claims 65 to 70.

72. A building, the building including a plurality of building unit assemblies according to any one of claims 1 , 2 or 18, with infill material, such as concrete, being poured into the floor formwork creating the floors of the building.