D.C. Mun. Regs. tit. 11, r. 11-F205
The maximum permitted height of a penthouse or rooftop structure and number of stories, except as limited by Subtitle C § 1501 on the roof of a single household dwelling or flat, shall be as set forth in the following table:
TABLE F § 205.1: MAXIMUM PENTHOUSE AND ROOFTOP STRUCTURE HEIGHT AND NUMBER OF STORIES
Zones | Maximum Height | Maximum Number of Stories |
RA-1 | 12 ft. | 1 |
RA-2 | 12 ft., except 15 ft. for penthouse mechanical space | 1; Second story permitted for penthouse mechanical space |
RA-3 | 12 ft., except 18 ft. 6 in. for penthouse mechanical space | 1; Second story permitted for penthouse mechanical space |
RA-4 | 20 ft. | 1 plus mezzanine; Second story permitted for penthouse mechanical space |
RA-5 | 20 ft. | 1 plus mezzanine; Second story permitted for penthouse mechanical space |
Notwithstanding Subtitle F § 205.1, in any of the RA-1 and RA-2 zones, a mechanical penthouse or rooftop structure with a maximum height of eighteen feet, six inches, (18 ft. 6 in.) shall be permitted on a non-residential building constructed pursuant to Subtitle F §§ 203.3 through 203.6.
D.C. Mun. Regs. tit. 11, r. 11-F205