Above we have a circa-1936 floor plan of a three-unit Greenbelt apartment building. On the left is its "Honeymoon Unit," with a single bedroom. The typical rent for such an abode would run from between $18-$25 a month for an apartment, and between $28-$41 a month for an individual house. In 1939, the typical green suburb family were paying around 90 cents per month for water and $3 per month for electricity.
Drawing from Library of Congress

Prospective housing designs for the Greenhills project. In all of the three planned cities, homes had a "service side" (for automobile access, deliveries, utility meters and garbage collection), and "garden side," which would open on a central green space. 
Drawing from Library of Congress