ab ▁at ▁grade . ▁They ▁can ▁also ▁be ▁built ▁to ▁multi - story ▁height s . ▁Mot els ▁and ▁other ▁multi - family ▁structures ▁have ▁been ▁built ▁using ▁mod ular ▁construction ▁techniques . ▁The ▁height ▁to ▁which ▁a ▁mod ular ▁structure ▁can ▁be ▁built ▁depends ▁on ▁juris diction , ▁but ▁a ▁number ▁of ▁countries , ▁especially ▁in ▁Asia , ▁allow ▁them ▁to ▁be ▁built ▁to ▁ 2 4 ▁flo ors ▁or ▁more . ▁ ▁Ex terior ▁wall ▁surfaces ▁can ▁be ▁final ized ▁in ▁the ▁plant ▁production ▁process ▁or ▁in ▁the ▁case ▁of ▁brick / stone ▁v ene ers , ▁field ▁applications ▁may ▁be ▁the ▁build ers ' ▁choice . ▁Ro of ▁systems ▁also ▁can ▁be ▁applied ▁in ▁the ▁field ▁after ▁the ▁basic ▁installation ▁is ▁completed . ▁ ▁U . S . ▁regional ▁differences ▁with ▁mod ular ▁construction ▁We ather , ▁population ▁density , ▁ge ographical ▁distances , ▁and ▁local ▁housing ▁architecture ▁play ▁a ▁role ▁in ▁the ▁use ▁of ▁mod ular ▁construction ▁for ▁home ▁building . ▁Because ▁mod ular ▁construction ▁is ▁so ▁adapt able , ▁it ▁has ▁begun ▁to ▁per me ate ▁every ▁region ▁of ▁the ▁U . S . ▁ ▁N ortheast ▁The ▁n ortheast ▁is ▁populated ▁with ▁fact ories ▁that ▁can ▁combine ▁mod ular ▁housing ▁design ▁with ▁other ▁construction ▁methods ▁such ▁as ▁panel ization ▁and ▁S IP s . ▁Mod ules ▁are ▁typically ▁limited ▁to ▁ 1 6 ' ▁width ▁and ▁up ▁to ▁ 7 0 ' ▁lengths ▁because ▁of ▁the ▁narrow ▁road ▁structure ▁and ▁dens ely ▁populated ▁areas ▁of ▁the ▁region