A method of appraising rental properties is provided that provides guidelines for government agency when determining rental subsidies to be paid to landlords and property owners. The method comprises cataloging and storing data related to the property and the tenants themselves, wherein the condition of the property, its amenities, the anticipated utilities for the property, and the local real estate market are accounted for in determining a reasonable rent to be paid to the landlord or property owner offering subsided housing to low income families. In carrying out the these objects, the present invention provides an application layer executed on a computer or other like programmable apparatus, a network, and a storage database for cataloging external data from public sources and from agency personnel directly. The method provides a reasonable rent calculation that is adapted to incentivize property owners to maintain their property and to prevent government agency waste.