The purposes of the D-3 zone are to promote high-density development of commercial and mixed uses in the eastern portion of the District’s traditional downtown and, through height restrictions, to respond to federal concerns for the security of the nearby U.S. Capitol and Union Station.

A building with frontage on a designated primary or secondary street shall meet the design requirements on Subtitle I § 602.

The following Downtown Sub-Areas are found within the D-3 zone: Capitol Security, Massachusetts Avenue Corridor and Mt. Vernon Square, North Capitol Street Corridor.

Development Standards
Floor Area Ratio (max.)1 Height (ft.)2 Penthouse Height (ft.)/Stories Lot Occupancy
Rear Yard (ft.) Side Yard (ft.) Green Area Ratio Zoning Regulation Reference
D-3 9.0 110 20 100 2.5 in. per 1 ft. of vertical distance from the mean finished grade at the middle of the rear of the
structure to the highest point of the main roof or parapet, but not less than 12 ft.
If provided, at least 2 in. wide for each 1 ft. of height of building but no less than 5 ft. 0.20 Subtitle I, Chapter 5
6.5 (non-residential) 1 plus mezzanine; Second story permitted for penthouse mechanical space


Use Permissions 4 Courts Parking 5 Loading Alley Lots Front Build-to
Subtitle U, Chapter 7 Subtitle I § 207 Subtitle C, Chapter 7 Subtitle C, Chapter 9 Subtitle I § 210 Subtitle I § 203

The D-3 zone is not subject to the Inclusionary Zoning provisions of Subtitle C, Chapter 10; however, a building in the D-3 zone may generate or use credits in accordance with Subtitle I, Chapters 8 and Chapter 9, which explains the credit system relating to Transferable Development Rights (“TDR”) or Combined Lot Development (“CLD”) rights.

1The maximum permitted FAR can be achieved if (a) all FAR is residential; (b) If all FAR exceeding the non-residential density permitted in Subtitle I 516.3 is residential; or (c) If conditions (a) or (b) are not satisfied, through the use of credits pursuant to Subtitle I, Chapters 8 and Chapter 9.
2 Maximum permitted building height, not including the penthouse in the D-3 zone, is limited to 90 ft. on the portion of the site occupied by a historic landmark or a contributing building within a historic district.
3 Subject to applicable regulations governing courts, side or rear yards, front setback or build-to lines, easements or historic preservation
4 Unless modified in in Subtitle I, Chapter 3 or by regulations governing a specific Downtown sub-area.
5 No parking is required in this zone, but parking spaces provided are subject to Subtitle C, Chapter 7