Adding dormers to a residential property in New York City requires compliance with specific regulations and obtaining necessary permits. The homeowner must adhere to local building codes and zoning ordinances, which may include height restrictions, setback requirements, and design guidelines. Typically, a construction permit and a work permit are essential for the dormer project. Additionally, obtaining approval from the local building department and, in some cases, neighborhood associations or community boards may also be required before commencing the construction.