1. (a)
   Subtitle A, Authority and Applicability; 
2. (b)
   Subtitle B, Definitions, Rules of Measurement, and Use Categories;
3. (c)
   Subtitle C, General Rules; and
4. (d)
   Subtitle U, Use Permissions.

1. (a)
   Provide for the orderly development and use of land and structures in areas predominantly characterized by low- to moderate-density residential development;
2. (b)
   Recognize and reinforce the importance of neighborhood character, walkable neighborhoods, housing affordability, aging in place, preservation of housing stock, improvements to the overall environment, and low- and moderate-density housing to the overall housing mix and health of the city;
3. (c)
   Allow for limited compatible accessory and non-residential uses;
4. (d)
   Allow for the matter-of-right development of existing lots of record;
5. (e)
   Establish minimum lot area and lot width for the subdivision and creation of new lots of record; and
6. (f)
   Discourage multiple dwelling unit development.

1. (a)
   Protect quiet residential areas now developed with detached houses and adjoining vacant areas likely to be developed for those purposes; and 
2. (b)
   Stabilize the residential areas and promote a suitable environment for family life.

1. (a)
   Height and number of stories;
2. (b)
   Density and lot occupancy;
3. (c)
   Yards and setbacks; and
4. (d)
   Environmental performance.
   
   
   
   

1. (a)
   In any of the R-1 or R-2 zones, the maximum permitted FAR for a public recreation and community center shall be 0.9; and
2. (b)
   In any of the R-3 zones, the maximum permitted FAR for a public recreation and community center shall be 1.8.
   

1. (a)
   “Time of application” shall mean the earlier of either:

   1. (1)
      The Department of Buildings officially accepts as complete the application for the building permit for the proposed construction; or
   2. (2)
      The Office of Zoning officially accepts as complete an application for zoning relief for the proposed construction;
2. (b)
   “Solar energy system” shall mean a solar energy system of at least 2kW in size that, at the time of application, is either:

   1. (1)
      Legally permitted, installed, and operating; or
   2. (2)
      Authorized by an issued permit; provided that the permitted solar energy system is operative within six (6) months after the issuance of the solar energy system permit, not including grid interconnection delays caused solely by a utility company connecting to the solar energy system;
3. (c)
   “Significantly interfere” shall mean that the proposed construction increases the shading incident on the solar energy system by more than five percent (5%) as determined by a comparative solar shading study acceptable to the Zoning Administrator; and
4. (d)
   All applications for the proposed construction, whether for a building permit or for zoning relief, must include one of the following:

   1. (1)
      An affidavit by the applicant stating that there is no solar energy system on an abutting property;
   2. (2)
      A comparative solar shading study which meets the minimum standard established by the Zoning Administrator for the purpose of determining the increased annual incident solar shading by percent; or
   3. (3)
      A written agreement executed by the owner of the impacted solar energy system accepting the interference with the solar energy system.

The Board of Zoning Adjustment may grant relief from the requirements of Subtitle D § 204.1 as a special exception pursuant to Subtitle X, Chapter 9, and subject to the following conditions:

Except as provided elsewhere in this title, the minimum required rear yard shall be as set forth in the following table:

Except as provided elsewhere in this title, the maximum permitted lot occupancy shall be as set forth in the following table:

Except as provided elsewhere in this title, the minimum required percentage of pervious surface of a lot shall be as set forth in the following table:

1. (a)
   Relief from the GFA limitations of Subtitle D § 201.2 and the FAR limitations of Subtitle D § 201.3 shall be limited to a maximum of 1.8 FAR; and
2. (b)
   Relief from the lot occupancy limitations of Subtitle D § 210.1 shall be limited to a maximum forty percent (40%) lot occupancy provided the applicant demonstrates to the Board’s satisfaction that the proposed increase is consistent with the Department of Parks and Recreation’s policy of preserving open space.
   

1. (a)
   Preserve and enhance the park-like setting of designated neighborhoods adjacent to streams or parks by regulating alteration or disturbance of terrain, destruction of trees, and ground coverage of permitted buildings and other impervious surfaces;
2. (b)
   Preserve the natural topography and mature trees to the maximum extent feasible in a residential neighborhood;
3. (c)
   Prevent significant adverse impact on adjacent open space, parkland, stream beds, or other environmentally sensitive natural areas; and
4. (d)
   Limit permitted ground coverage of new and expanded buildings and other construction, so as to encourage a general compatibility between the siting of new buildings and the existing neighborhood.

1. (a)
   Preserve and enhance the park-like setting of designated neighborhoods bounded by Connecticut Avenue and Thirty-Second Street on the west, Rock Creek Park on the east, Fort Circle National Park and Nevada Avenue, NW on the north, and Melvin C. Hazen Park and adjacent to streams and parks on the south, by regulating alteration or disturbance of terrain, destruction of trees, and the ground coverage of permitted buildings and other impervious surfaces. It includes Soapstone Valley Park as well as Melvin C. Hazen Park;
2. (b)
   Preserve the natural topography and mature trees to the maximum extent feasible in the Forest Hills neighborhoods;
3. (c)
   Prevent significant adverse impact on adjacent open space, parkland, stream beds, or other environmentally sensitive natural areas; and
4. (d)
   Limit permitted ground coverage of new and expanded buildings and other construction, so as to encourage a general compatibility between the siting of new buildings or construction and the existing neighborhood.

1. (a)
   Preclude enlargement of a principal building in existence as of May 18, 2007; or
2. (b)
   Create nonconformity of a structure as regulated by this title.

The base zone development standards in Subtitle D, Chapter 2 shall apply to the R‑1A/TS/NO zone except as specifically modified by this chapter. In the event of a conflict between the provisions of this chapter and other regulations of this title, the provisions of this chapter shall control.

1. (a)
   Promote the public health, safety, and general welfare on land adjacent to or in close proximity to the highly sensitive and historically important Naval Observatory in keeping with the goals and policies of the Federal and District elements of the Comprehensive Plan and the adopted Master Plan for that facility;
2. (b)
   Ensure that public land within the zone shall be used in a manner consistent with the historic or ceremonial importance and special missions of the Naval Observatory;
3. (c)
   Reflect the importance of the Naval Observatory to the District of Columbia and to the Nation;
4. (d)
   Protect Federal interest concerns, including the critical scientific mission performed at the Naval Observatory and the security needs of the Vice President's residence; and
5. (e)
   Reduce or eliminate any possible harm or restrictions on the mission of the Federal establishment within the zone. 

1. (a)
   The height of a building shall be the vertical distance measured from the level of the curb opposite the middle of the front of the building to the highest point of the roof or parapet; and
2. (b)
   The curb elevation opposite the middle of the front of the building shall be determined as the average elevation of the lot from its front line to its rear line.

1. (a)
   Present and proposed development within and adjacent to the R-1A/TS/NO zone;
2. (b)
   Goals, objectives, and policies pertaining to federal facilities, as found in the Comprehensive Plan and the Master Plans for the federal facilities within the R-1A/TS/NO zone; and
3. (c)
   Role, mission, and functions of the federal facilities within the R-1A/TS/NO zone, considering the effect that the proposed development would have on such facilities. 

1. (a)
   Office of Planning;
2. (b)
   District Department of Transportation;
3. (c)
   Department of Housing and Community Development;
4. (d)
   The Historic Preservation Office if a historic district or historic landmark is involved; and
5. (e)
   The National Capital Planning Commission. 

1. (a)
   Preclude enlargement of a principal building in existence as of May 18, 2007; or
2. (b)
   Create nonconformity of a structure as regulated by this title.

The base zone development standards in Subtitle D, Chapter 2 shall apply to the R‑1B/NO and R-3/NO zones except as specifically modified by this chapter. In the event of a conflict between the provisions of this chapter and other regulations of this title, the provisions of this chapter shall control.

1. (a)
   Promote the public health, safety, and general welfare on land adjacent to or in close proximity to the highly sensitive and historically important Naval Observatory in keeping with the goals and policies of the Federal and District elements of the Comprehensive Plan and the adopted Master Plan for that facility;
2. (b)
   Ensure that public land within the zone shall be used in a manner consistent with the historic or ceremonial importance and special missions of the Naval Observatory;
3. (c)
   Reflect the importance of the Naval Observatory to the District of Columbia and the Nation;
4. (d)
   Protect Federal interest concerns, including the critical scientific mission performed at the Naval Observatory and the security needs of the Vice-President's residence; and
5. (e)
   Reduce or eliminate any possible harm or restrictions on the mission of the Federal establishment within the zone. 

1. (a)
   The height of a building shall be the vertical distance measured from the level of the curb opposite the middle of the front of the building to the highest point of the roof or parapet; and
2. (b)
   The curb elevation opposite the middle of the front of the building shall be determined as the average elevation of the lot from its front line to its rear line.  

1. (a)
   Present and proposed development within and adjacent to the subject zone;
2. (b)
   Goals, objectives, and policies pertaining to federal facilities, as found in the Comprehensive Plan and the Master Plans for the federal facilities within the subject zone; and
3. (c)
   Role, mission, and functions of the federal facilities within the subject zone, considering the effect that the proposed development would have on such facilities. 

1. (a)
   The Office of Planning;
2. (b)
    The District Department of Transportation;
3. (c)
   The Department of Housing and Community Development;
4. (d)
   The Historic Preservation Office if a historic district or historic landmark is involved; and
5. (e)
   The National Capital Planning Commission.

1. (a)
   Preserve and enhance the low-density character of Wesley Heights by regulating construction and alteration of residential and other buildings in the area;
2. (b)
   Preserve in general the current density of the neighborhood;
3. (c)
   Allow reasonable opportunities for owners to expand their houses; and
4. (d)
   Preserve existing trees, access to air and light, and the harmonious design and attractive appearance of the neighborhood. 

1. (a)
   GFA shall not include:

   1. (1)
      The first two hundred square feet (200 sq. ft.) of an open porch, or total open porch space if there is more than one (1) open porch; and
   2. (2)
      The first six hundred square feet (600 sq. ft.) of a garage shall not count in GFA; and
2. (b)
   GFA shall include basement or cellar floor area with a finished floor and a floor-to-ceiling height in excess of six feet, six inches (6 ft., 6 in.); provided that this addition to GFA shall count only up to a floor area equal to five (5) times the total fenestration area for the entire basement or cellar floor area, including that with unfinished floor and floor-to-ceiling heights below six feet, six inches (6 ft., 6 in.). 

1. (a)
   Structures on lots between five thousand square feet (5,000 sq. ft.) and six thousand six hundred and sixty-seven square feet (6,667 sq. ft.) may occupy up to two thousand square feet (2,000 sq. ft.); and
2. (b)
   Structures on lots less than five thousand square feet (5,000 sq. ft.) may occupy up to forty percent (40%) of the area of the lot.  

1. (a)
   Promote the conservation, enhancement, and stability of the low-density, single dwelling unit neighborhood for housing and neighborhood-related uses;
2. (b)
   Control the expansion of nonresidential uses, and/or further conversion of residential housing to nonresidential uses in order to maintain the housing supply and minimize the external negative impacts of new nonresidential uses that are permitted in the R-1B/SH zone in order to preserve neighborhood quality; and
3. (c)
   Allow neighborhoods to continue to provide a range of health and social service facilities as well as private institutions that provide cultural and religious enrichment and economic vitality, but within the framework of improved public review and control over the external effects of nonresidential uses. The objective is to make more compatible the Comprehensive Plan's goals and policies for maintaining the quality and stability of residential neighborhoods with other policies related to the reasonable provision of human services throughout the District of Columbia. 

1. (a)
   Respond to concerns that over a period of years approximately one (1) in every ten (10) houses in the R-1B/SH zone north of Colorado Avenue, N.W. has been converted to a nonresidential use, a much higher ratio than has been identified for any other similarly zoned neighborhood in the District of Columbia; and south of Colorado Avenue, N.W., address concerns that more than twenty percent (20%) of the residentially zoned land is used for nonresidential purposes;
2. (b)
   Recognize that the neighborhood accommodates a significant number and range of human service facilities and private institutions to an extent that new and significantly expanded nonresidential use facilities should be governed by improved public review to ameliorate adverse impacts on immediate and nearby neighbors and to preserve a predominantly single dwelling unit residential character;
3. (c)
   Respond to the District of Columbia Comprehensive Plan’s identification of the number of nonresidential uses in the neighborhood as a problem; and
4. (d)
   Address the impacts of the number of nonresidential uses and the conversion of houses to these uses in the neighborhood as reflected in the Comprehensive Plan. 

The base zone development standards in Subtitle D, Chapter 2 shall apply to the R-3/FB zone except as specifically modified by this chapter. In the event of a conflict between the provisions of this chapter and other regulations of this title, the provisions of this chapter shall control.

1. (a)
   Enhance the residential character of the area by maintaining existing low-scale residential uses, human scale streetscape, and historic character;
2. (b)
   Enhance the human-scale streetscape by maintaining the public space in front of the buildings as landscaped green spaces and limiting future curb cuts;
3. (c)
   Require a scale of development consistent with the Comprehensive Plan; and the characteristics of the low scale residential row house neighborhood that formed the basis on which the area was designated a historic district;
4. (d)
   Protect the integrity of the historic district, its small scale, and open spaces; require compatibility of any development with the purposes of the Historic Landmark and Historic District Protection Act of 1978, effective March 3, 1979 (D.C. Law 2-144, as amended; D.C. Official Code §§ 6-1101 to 6-1115 (2012 Repl.), formerly codified at D.C. Official Code §§ 5-1001 to 5-1015 (1994 Repl. & 1999 Supp.)), and preclude demolitions or partial demolitions that would lead to an increase in height and density inappropriate to the area;
5. (e)
   Preserve areas planned as open backyards and alleyways that provide the only access to historic alley dwellings, and to protect the light, air, and privacy that they provide; and
6. (f)
   Encourage greater use of public transportation through use of the nearby Metrorail Station, so as to protect the narrow residential streets and alleys from the deleterious effects of disruptive excessive traffic. 

1. (a)
   Were nonconforming prior to April 17, 1992; and
2. (b)
   Not authorized by relief granted by the Board of Zoning Adjustment.  

The base zone development standards in Subtitle D, Chapter 2 shall apply to the R-1A/CBUT zone except as specifically modified by this chapter. In the event of a conflict between the provisions of this chapter and other regulations of this title, the provisions of this chapter shall control.

1. (a)
   Provide for areas predominantly developed with detached houses on large lots;
2. (b)
   Preserve and enhance the park-like setting of the area by regulating alteration or disturbance of terrain, destruction of trees, and ground coverage of permitted buildings and other impervious surfaces, and by providing for widely spaced residences;
3. (c)
   Preserve the natural topography and mature trees to the maximum extent feasible in a residential neighborhood;
4. (d)
   Prevent significant adverse impact on adjacent open space, parkland, stream beds, or other environmentally sensitive natural areas;
5. (e)
   Limit permitted ground coverage of new and expanded buildings and other construction, so as to encourage a general compatibility between the siting of new buildings or construction and the existing neighborhood; and
6. (f)
   Limit the minimum size of lots so as to prevent significant adverse impact on existing infrastructure, especially on traffic and pedestrian safety, and to achieve the other purposes listed in this subsection. 

1. (a)
   Preclude enlargement of a principal building in existence as of July 30, 1999; or
2. (b)
   Create nonconformity of a structure as regulated by Subtitle C, Chapter 2. 

1. (a)
   Protect the Georgetown National Historic Landmark District and its historic character, buildings, and open space in a manner consistent with the goals and mandates of the Historic Landmark and Historic District Protection Act of 1978, and the Old Georgetown Act, approved September 22, 1950 (64 Stat. 903; D.C. Official Code §§ 6-1201-1206);
2. (b)
   Protect the integrity of “contributing buildings,” as that term is defined by the Historic Landmark and Historic District Protection Act of 1978;
3. (c)
   Recognize the compatibility of any development with the purposes of the Old Georgetown Act and the Historic Landmark and Historic District Protection Act of 1978;
4. (d)
   Limit permitted ground coverage of new and expanded buildings and other construction to encourage a general compatibility between the siting of new or expanded buildings and the existing neighborhood; and
5. (e)
   Retain the quiet residential character of these areas and control compatible nonresidential uses. 

1. (a)
   Thirty-five feet (35 ft.) and three (3) stories, not including a penthouse or rooftop structure; or
2. (b)
   Forty feet (40 ft.), not including a penthouse or rooftop structure, only if a property adjacent on either side has a building height of forty feet (40 ft.) or greater.

1. (a)
   The portion of the building, excluding closed court, exceeding the lot coverage shall not exceed twenty feet (20 ft.) in height or two (2) stories; and
2. (b)
   The total lot occupancy shall not exceed seventy percent (70%) in all R-2and R-3 zones.

1. (a)
   Be subordinate to and located on the same lot as the building, to which it is accessory; provided, that an accessory building may contain a parking space accessory to, and required for, a use on another lot where specifically permitted under other provisions of this title;
2. (b)
   Be used for purposes which are incidental to the use of the principal building; provided that no more than one (1) accessory apartment shall be allowed;
3. (c)
   Be secondary in size compared to the principal building;
4. (d)
   Be constructed after the construction of a principal building on the same lot; and
5. (e)
   Not be constructed in front of the principal building.

1. (a)
   Set back at least seven and one-half feet (7.5 ft.) from the centerline of any alley; and
2. (b)
   Not occupying, in combination with all accessory buildings on a lot, more than thirty percent (thirty percent (30%)) of the area of a required rear yard.

1. (a)
   Lot occupancy subject to the following table:

1. (a)
   Lot occupancy as limited in Table D § 5201.1(a);

1. (a)
   Yards, including alley centerline setback; and
2. (b)
   Pervious surface.

1. (a)
   The light and air available to neighboring properties shall not be unduly affected;
2. (b)
   The privacy of use and enjoyment of neighboring properties shall not be unduly compromised;
3. (c)
   The proposed addition or accessory structure, together with the original building, or the new principal building, as viewed from the street, alley, and other public way, shall not substantially visually intrude upon the character, scale, and pattern of houses along the street or alley frontage; and
4. (d)
   In demonstrating compliance with paragraphs (a), (b), and (c) of this subsection, the applicant shall use graphical representations such as plans, photographs, or elevation and section drawings sufficient to represent the relationship of the proposed addition, new building, or accessory structure to adjacent buildings and views from public ways.

1. (a)
   District Department of Transportation (DDOT);

1. (a)
   Department of Public Works (DPW);
2. (b)
   Metropolitan Police Department (MPD);
3. (c)
   Fire and Emergency Medical Services Department (FEMS);
4. (d)
   DC Water (WASA); and
5. (e)
   If a historic district or historic landmark is involved, the Historic Preservation Office (HPO).

1. (a)
   Tree removal, grading, and topographical change shall be limited to the maximum extent possible, consistent with construction of a building permitted by the standards of this section;
2. (b)
   The applicant shall demonstrate that there are specific physical characteristics of the lot that justify the exception;
3. (c)
   The building and overall site plat of the lot for which the special exception is sought shall be generally consistent with the purpose of the R-1A/CBUT, R-1A/FH, R-1A/TS, R‑1A/TS/NO, R-1B/FH, R-1B/TS, and R-2/FH zones and will not adversely affect neighboring property; and
4. (d)
   The Board of Zoning Adjustment may impose requirements as to design, appearance, tree protection practices during construction, buffering, and other requirements as it deems necessary to achieve the purposes of this section and may vary side and rear yard requirements in order to achieve the purposes of this section.

1. (a)
   Office of Planning;
2. (b)
   District Department of Transportation, Urban Forestry Division;
3. (c)
   Department of Parks and Recreation;
4. (d)
   Department of Energy and Environment, Watershed Protection Division, Technical Services Branch; and
5. (e)
   National Park Service, U.S. Department of the Interior.

1. (a)
   A site plan for development, including computation and illustration of total lot occupancy and impervious surface ratio, and regulated trees proposed to be removed; and
2. (b)
   A plan and statement indicating how trees to be preserved on the lot will be protected during the construction period, including reference to proposed procedures to guard against long-term damage by such factors as soil compaction.