What is considered a residential building?

The term “residential building” includes:

  1. detached one-or-two family dwellings having not more than three stories above grade plane;
  2. buildings that consist of three or more attached townhouse units and have not more than three stories above grade plane;
  3. buildings that are classified in Group R-2, R-3 or R-4 and have not more than three stories above grade plane;