space is defined between the two surfaces an embodiment of this may be seen more clearly in fig1 a between building module 102 and building module 104 in some embodiments the junction space may comprise utility hookups or connections between a building module 102 and building module 104 or between a first housing unit 100 and second vertically positioned housing unit 100 as discussed above shown in fig3 c is a floor plan of an embodiment of a prefabricated building module 104 briefly a building module 104 may comprise one or more extendable partitions 112 c and one or more storage spaces 300 302 and 308 in some embodiments an area 310 of building module 104 may comprise inter floor utility connections as discussed above in some embodiments storage spaces 300 302 and 308 may comprise a door or doors which may be hinged or sliding doors for example in one embodiment storage space 300 may be used for coats and or shoes by an entry to housing unit 100 and may not include a door alternately a storage area 308 may comprise a closet for a bedroom of housing unit 100 and may include a door or doors in some embodiments a storage area 302 may comprise shelves for use as a pantry in other embodiments a storage area 302 may comprise an appliance such as a refrigerator a washing machine a clothes dryer or a combination washing machine and clothes dryer in a further embodiment storage area 302 may comprise electrical and plumbing connections for appliances in another further embodiment storage area 302.