s , ▁urban ▁reform ers ▁began ▁working ▁on ▁modern izing ▁cities ; ▁their ▁efforts ▁to ▁create ▁" uniform ity ▁within ▁areas , ▁less ▁mixture ▁of ▁social ▁classes , ▁maximum ▁priv acy ▁for ▁each ▁family , ▁much ▁lower ▁density ▁for ▁many ▁activities , ▁buildings ▁set ▁back ▁from ▁the ▁street , ▁and ▁a ▁perman ently ▁built ▁order " ▁all ▁meant ▁that ▁housing ▁for ▁single ▁people ▁had ▁to ▁be ▁cut ▁back ▁or ▁elimin ated . ▁ ▁By ▁the ▁early ▁ 1 9 3 0 s , ▁urban ▁reform ers ▁were ▁typically ▁using ▁codes ▁and ▁z oning ▁to ▁en force ▁" uniform ▁and ▁protected ▁single - use ▁resident ial ▁district [ s ] ▁of ▁private ▁houses ", ▁the ▁reform ers ' ▁preferred ▁housing ▁type . ▁ ▁In ▁ 1 9 3 6 , ▁the ▁F HA ▁Property ▁Stand ards ▁defined ▁a ▁dwell ing ▁as ▁" any ▁structure ▁used ▁princip ally ▁for ▁resident ial ▁purposes ", ▁not ing ▁that ▁" com mer cial ▁room ing ▁houses ▁and ▁tour ist ▁homes , ▁san it ari ums , ▁tour ist ▁cab ins , ▁clubs , ▁or ▁frat ern ities ▁would ▁not ▁be ▁considered ▁dwell ings " ▁as ▁they ▁did ▁not ▁have ▁the ▁" private ▁kitchen ▁and ▁a ▁private ▁bath " ▁that ▁reform ers ▁viewed ▁as ▁essential ▁in ▁a ▁" pro per ▁home ". ▁▁ ▁The ▁F HA ▁rules ▁called ▁the ▁existence ▁of ▁stores , ▁offices ▁or ▁r ental ▁housing ▁as ▁" ad verse ▁influ ences " ▁and ▁" undes irable ▁community ▁conditions ", ▁which ▁reduced ▁the ▁invest ment ▁and ▁repair