Interpretation ZA-007: Roof Top Architectural Element is superseded in part by D.C. Municipal Regulations Title 11, Subtitle E, Section 204.1 and 204.2. 

Applicants should also be aware of the “three foot rule,” that an addition of a floor or penthouse, usually behind the protected architectural rooftop element, must be set back at least three feet from the element in order to help preserve its architectural integrity.