D.C. Mun. Regs. tit. 11-D, § 5201
5201.1 For an addition to a principal residential building with one (1) principal dwelling unit on a non-alley lot or for a new principal residential building on a substandard non-alley record lot as described by Subtitle C § 301.1, the Board of Zoning Adjustment may grant relief from the following development standards of this subtitle as a special exception, subject to the provisions of this section and the general special exception criteria at Subtitle X, Chapter 9:
(a) Lot occupancy subject to the following table:
TABLE D § 5201.1(a): MAXIMUM PERMITTED LOT OCCUPANCY BY SPECIAL EXCEPTION
| Zones | Type of Structure | Maximum Percentage of Lot Occupancy (%) |
|---|---|---|
| All R-3 zones except R-3/GT | All Structures | 70 |
| R-3/GT | Row | |
| R-3/GT | Detached Semi-detached | 50 |
| All other R zones | All Structures |
(b) Yards, including alley centerline setback; and
(c) Pervious surface.
5201.2 For a new or enlarged accessory structure to a residential building with only one (1) principal dwelling unit on a non-alley lot, the Board of Zoning Adjustment may grant relief from the following development standards as a special exception, subject to the provisions of this section and the general special exception criteria at Subtitle X, Chapter 9:
(a) Lot occupancy as limited in Table D § 5201.1(a); -
(b) Maximum building area of an accessory building;
Yards, including alley centerline setback; and
(d) Pervious surface.
5201.3 For a new or enlarged principal building on an Alley Record Lot, the Board of Zoning Adjustment may grant relief from the following development standards as
a special exception, subject to the provisions of this section and the general special exception criteria at Subtitle X, Chapter 9:
Yards, including alley centerline setback; and
(b) Pervious surface.
5201.4 An application for special exception relief under this section shall demonstrate that the proposed addition, new principal building, or accessory structure shall not have a substantially adverse effect on the use or enjoyment of any abutting or adjacent dwelling or property, specifically:
5201.5 The Board of Zoning Adjustment may require special treatment in the way of design, screening, exterior or interior lighting, building materials, or other features for the protection of adjacent and nearby properties.
5201.6 This section shall not be used to permit the introduction or expansion of a nonconforming use, lot occupancy beyond what is authorized in this section, height, or number of stories as a special exception.
5201.7 Where an application requests relief from the alley centerline setback requirements under this section, the Office of Zoning shall refer the application to the following agencies for their review and recommendations, to be filed in the case record within the forty- (40) day period established by Subtitle A § 211:
(a) District Department of Transportation (DDOT);
(b) Department of Public Works (DPW);
(c) Metropolitan Police Department (MPD);
(d) Fire and Emergency Medical Services Department (FEMS);
(e) DC Water (WASA); and
(f) If a historic district or historic landmark is involved, the Historic Preservation Office (HPO).
SOURCE: Final Rulemaking published at 63 DCR 2447, 2834 (March 4, 2016 – Part 2); as amended by Final Rulemaking published at 64 DCR 8596 (September 1, 2017); as amended by Final Rulemaking published at 66 DCR 2337 (February 22, 2019); as amended by Final Rulemaking published at 67 DCR 8068 (July 3, 2020); as amended by Errata Notice published at 68 DCR 5013 (May 7, 2021); as amended by Final Rulemaking published at 69 DCR 000896 (February 4, 2022); as amended by Final Rulemaking published at 70 DCR 011297 (August 25, 2023).