Zoning classifications are confusing but might make the difference between a run of the mill row home and a development opportunity. Philadelphia has recently updated the code to make it simpler but the old designations are still listed in public records so you have to translate the old code into the updated designation in order to know what can be done on the property by right. One important type of designation allows for a multi-family property, the most common being RM1. With a multi-family designation the property owner has the right to convert the property into condos, a duplex, triplex, or any number of units that the building code will allow depending upon square footage. This is hardly cut and dry  and a professional should be consulted to make sure you get the right answer, but the city offers a quick reference guide here. When selling your property be sure to understand how your zoning could effect it’s market value.