Early in the film, Dave's truck license plate says MATT 725, seen out the garage door during the hurricane. Matthew 7:25 in the Bible reads "The rain came down, the streams rose, and the winds blew and beat against that house; yet it did not fall, because it had its foundation on the rock." (NIV)
It was Kaya Scodelario's idea for her character to be barefoot for most of the movie. She fought to have her character barefoot because she knew, as a woman, if you step in poop or mud in flip flops, instinct is to take them off.
The last name of the main protagonists is 'Keller', which is the German word for 'basement'. The largest part of the film takes place in a basement. However, it remains arguable whether this was intended by the film makers.
This is the first horror film Sam Raimi produced in many years without his longtime producing partner Rob Tapert