the fha rules called the existence of stores, offices or rental housing as "adverse influences" and "undesirable community conditions", which reduced the investment and repair support provided in any neighbourhood that deviated from the preferred single family home use. land use reformers also passed zoning rules that indirectly reduced rooming houses: banning mixed residential and commercial use in neighbourhoods, an approach which meant that any remaining rooming house residents would find it hard to eat at a local cafe or walk to a nearby corner grocery to buy food. non-residential uses such as religious institutions (churches) and professional offices (doctors, lawyers) were still permitted under these new zoning rules, but working class people (plumbers, mechanics) were not allowed to operate their businesses.