The high-density, mixed-used Downtown area of Washington, DC is covered by Subtitle I of the city’s new zoning regulations.

1. What You Need to Know about
DC’s New Zoning Regulations for
Downtown
Rachael Hesling

2. What You Need to Know about DC’s New
Zoning Regulations for Downtown
 A high-density mix of residential, office, retail, service, entertainment, and institutional uses, the area of Washington,
DC commonly known as Central Washington is covered by Subtitle I of the 2016 Washington, DC Zoning
Regulations.
 The overarching goal of Subtitle I is to ensure the orderly development and use of both land and buildings in the
busy and diverse Downtown area. Broadly speaking, Subtitle I aims to create a balanced mixture of land uses; protect
historic buildings, sites, and streets while keeping new development compatible with the existing character of the
area; and encourage the development of needed amenities, including public open spaces, affordable housing, and
adequate parking.
 Some of the strategies outlined in Subtitle I for achieving these goals include a blend of incentives and requirements
for retail, residential, and cultural land uses, as well as design guidelines and requirements for development in certain
retail, pedestrian, or historic areas. Subtitle I also allows for the creation of density credits and other flexible incentive
mechanisms to help meet goals for residential, historic, and open spaces. There’s also the possibility of selective
design review by the Zoning Commission in order to promote well-designed, mixed-used streetscapes in certain
areas.

3. Downtown provisions and regulations
 Property development in the Downtown area is governed by a mix of general development
standards and use regulations applicable to all D zones, and by location-specific regulations that
apply to individual D zones and other distinct sub-areas. D-zone boundaries can be found on
the District of Columbia Zoning Map. In addition, the regulations and provisions of Subtitle I
apply to all new building construction, as well as to existing buildings where alterations, repairs,
or additions made within the past 12 months exceed 100% of the assessed value of the building.

4. General development standards for D zones
 Chapter 2 of Subtitle I of DC’s new zoning regulations provides a comprehensive overview of the
general development standards that apply to all D-zone development. Specific design elements
and other property characteristics addressed in these general standards include:

5. Density and floor area ratio
 Many considerations for the floor area ratio (FAR) of D-zone buildings take into account the
status of historic landmarks or similar contributing buildings in historic districts. For example, a
historic landmark with an existing FAR of 6.0 or less is exempt from any minimum residential
requirements specified by the provisions of the lot’s particular zone, and may have the option of
generating density credits. Likewise, a historic landmark whose existing FAR is more than 6.0 may
not increase the FAR of the portion of the lot falling within the footprint of the historic structure,
but may have the option of occupying all existing floors of the building for uses permitted under
the zone’s provisions, and may similarly generate density credits.

6. Height
 Maximum permitted building heights are specified in zone-specific chapters of Subtitle I. In
addition, buildings on designated street segments in certain sub-areas may be subject to further
review; this includes buildings with frontage on Pennsylvania Avenue NW, the Massachusetts
Avenue corridor, South Capitol Street and North Capitol Street, Independence Avenue SW, and
the Mount Vernon Triangle Principal Intersection.

7. Lot occupancy
 Under Subtitle I, each building on any D-zone lot is permitted to occupy 100% of its lot.
(However, this permission may be limited by other regulations governing matters including side
and rear yards, front setbacks, easements, or historic preservation.)

8. Front build-to line
 Front build-to requirements, which broadly state that new buildings shall maintain a distance of
no more than four feet between each wall fronting a street and the property line between the lot
and the abutting street right-of-way, are applicable to walls facing either a designated primary
street segment or any avenue whose name is an official US state, commonwealth, or district.
These front build-to lines may be relaxed in special circumstances.

9. Rear yard
 All D zone structures must contain a rear yard, unless they are on a corner lot or on a through
lot, including lots that front at least three streets. Otherwise, the minimum rear yard depth is
measured as 2.5 inches per foot of building height. Regardless of building height, no rear yard is
to have a depth of less than 12 feet.

10. Side yard
 Side yards are not required for any principal structure located in a D zone. If a side yard is
provided, however, its minimum width must be at least four feet.

11. Green area ratio
 Buildings in zone D-2 must maintain a green area ratio of 0.30; buildings in all other D zones
must maintain a green area ratio of 0.20.

12. Accessory buildings
 It is possible for accessory buildings to be constructed in a D zone as long as the accessory
building and the principal building are situated on the same lot, the accessory building is both
smaller and subordinate to the principal building, and the purposes for which the accessory
building is used are incidental to the uses of the principal building. In addition, the accessory
building must comply with any zone-specific setback requirements.

13. Takoma (NC-2)
 A major focus of the NC-2 zoning regulations is to ensure that the Takoma Metro station and
surrounding neighborhood optimize open space in order to enhance retail and service uses and
encourage pedestrian traffic. Specific provisions aimed at accomplishing this goal include the
requirement of a minimum floor-to-ceiling height on ground floor developments; a limit on the
height of new buildings; and an emphasis on moderate-density development.

14. Cleveland Park (NC-3)
 Affordable housing and historic preservation are among the main purposes of the NC-3 zoning
regulations, whose provisions encourage development that is compatible with the 1978 Historic
Landmark and Historic District Protection Act. The zone also seeks to preserve existing housing in
order to avoid losing much-needed affordable residential units in the neighborhood.

15. Woodley Park (NC-4 and NC-5)
 The NC-4 zone permits moderate-density mixed-use development, while the NC-5 zone permits
compact, medium-density development that is mixed-use, but with an emphasis on residential
development. The primary intention of the NC-4 and NC-5 zoning regulations is to encourage
development on a scale compatible with existing buildings. In the Woodley Park area, this
involves a specific provision to limit the height of any new buildings.

16. Eighth Street Southeast (NC-6)
 Given the close proximity of the Eighth Street Southeast neighborhood to the Navy Yard, the
provisions of the NC-6 zoning regulations aim to encourage the development of new
neighborhood-serving businesses, particularly companies whose primary business will be with
the Navy. The zone will also maintain the neighborhood character by keeping building heights at
a low-level density that is compatible with the historic buildings around the Navy Yard entrance,
and improve pedestrian access to retail businesses by minimizing potential conflict areas with
vehicle traffic.

17. Georgia Avenue (NC-7 and NC-8)
 The regulations for both these zoning areas permit mixed-use development—NC-7 at a
moderate density, NC-8 at a medium density—including residential units located above ground-
floor commercial businesses. These regulations are intended to fulfill the objectives outlined in
the Georgia Avenue - Petworth Metro Station Area and Corridor Plan and the Great Streets
Framework Plan for 7th Street - Georgia Avenue, both approved and published in 2006.