DC’s Rowhouse Neighborhoods

The Zoning Commission (ZC) and Office of Planning (OP) have heard concerns voiced by residents about two issues impacting the District’s residential rowhouse neighborhoods – conversions of rowhouses to multi-family buildings, and additions to existing buildings, often called “pop ups” or “pop-outs”. The rowhouse areas are generally zoned R-4, which the Zoning Code defines as “those areas now developed primarily with row dwellings, but within which there have been a substantial number of conversions of the dwellings into dwellings for two (2) or more families.” In the R-4 or residential flat zone district, two dwelling units are permitted as a matter of right, although the R-4 zone is unique in that it also includes a provision that allows for the conversion, within set limits, of existing buildings into multi-family units. Even so, the Zoning Code goes on to state that “the R-4 District shall not be an apartment house district as contemplated under the General Residence (R-5) Districts, since the conversion of existing structures shall be controlled by a minimum lot area per family requirement.”


Many R-4 neighborhoods have seen an increasing number of conversions of buildings – both by right, and through variance requests to allow conversions with less than 900 square feet of land area per unit. This has had the effect of putting upward price pressures on single family housing stock with 3 or more bedrooms, pricing them out of the range of many families in many R-4 zoned areas.

OP looked carefully at the issues of conversions and inappropriate additions. We examined all of the R-4 zoned area and completed a detailed study of lot areas and building forms. Based on our discussions with R-4 residents and this research, OP submitted the following text amendments to the Zoning Commission on Tuesday, June 24th for consideration and possible set down (ZC Case 14-11).

1) Reduce Building Height:
OP has proposed that the regulations be amended to reduce the by-right height for a detached, semi-detached, rowhouse, or flat building in the R-4 district from 40 feet to 35 feet, but allow up to 40 feet by special exception subject to conditions. Our research found that the overwhelming majority of rowhouses in R-4 are less than 35’ feet in height.

2) Mezzanine Definition:
OP is proposing to change the definition of mezzanine so it is included in the number of stories. A mezzanine is a partial floor and under the current regulations, it does not count as one of the three permitted stories in R-4. However, adding this partial floor space can cause the building to rise higher than would otherwise be the case, so adds to the volume of the building.

3) Rowhouse / Flat Conversion to Multi-Family:

OP is proposing to eliminate the provision that allows for the conversion of rowhouses to multi-family buildings. The existing regulations limit the R-4 rowhouses to one dwelling unit or two units which is defined as a “flat”. However, there is also a provision that allows a conversion of a building or structure to multi-family units subject to a required minimum lot area of 900 square feet per unit. So, for example, a 2,700 sq.ft. lot would permit the rowhouse to be divided into 3 units; a 3,600 sq.ft. lot would permit the rowhouse to be divided into 4 units. In addition, there has been a large upswing in BZA cases requesting relief from this provision, to allow buildings on smaller lots to be subdivided into multi-family, or to allow more multi-family units than the regulation would permit. This is often accompanied by additions, sometimes extensive, to the existing building by adding new floors or extending floors to accommodate more units.

So, in a time when the demand for housing is great in DC, why would OP propose this? In addition to being inconsistent with the intent of the R-4 zone and sometimes the character of the neighborhood, this is having an impact on the diversity and the relative affordability of our family housing stock. The Comprehensive Plan provides substantial policy guidance directed at providing a diversity of housing options including family housing and protecting single-family neighborhoods.

Buildings with one and two dwelling units represent approximately 38 percent of the District’s housing stock, but only about 4 percent of the units in the housing pipeline over the next 15 years. Conversely, the District has a large supply of multi-family or mixed use zoned land and developments in the housing pipeline for multi-family housing that is appropriate to meet the demand of smaller households.

Few new multifamily buildings are being delivered with three or more bedrooms, unless they are part of housing planned to replace similarly-sized public housing units. Over the past three years, three-bedroom units have risen in price almost three times as fast as one-bedroom units – a reflection of the limited supply, subsequent demand pressure, and rapidly escalating prices. Families seeking to purchase relatively affordable homes are competing with developers who can pay more for a larger house than a family because they can profit by splitting up the building and selling smaller units. Ensuring that the R-4 zone remains a single-family rowhouse or flat zone can begin to address this pressure.

4) Conversion of Larger Non-Residential Buildings, by Special Exception
OP is proposing that the R-4 zone regulations continue to allow for the conversion of larger non-residential buildings, like a closed school or church, to facilitate the adaptive reuse of these non-residential buildings. OP is proposing that such a conversion be by special exception to allow for neighborhood input.

There is little if any implication on the production of Inclusionary Zoning (IZ) affordable units because the IZ requirements don’t apply in the R-4 zone until a project is 10 units or more and the conversion cases that would be limited by the proposed changes are typically 3 to 4 units. The larger projects such as school or church conversions will continue to be subject to the Inclusionary Zoning requirements.

OP believes that the combination of proposed amendments work to limit inappropriate additions while respecting the property rights of owners and preserving the character of the District’s residential rowhouse neighborhoods. The proposed amendments do not, however, stand alone. OP has also submitted the following proposals to the Zoning Commission through the Zoning Regulations Review (ZRR) (ZC Case 08-06A) process that work in tandem with the R-4 text amendments to accommodate new dwelling units:

1) Allow Accessory Apartments as a matter of right in low to moderate density residential zones;
2) Limit the height of a rooftop penthouse, currently allowed to be 18’6” tall, to 10’; and
3) Create two new zones that allow three (3) units per building and four (4) units per building. Although OP is not proposing to map these zones on any neighborhood, they would be zones available to a neighborhood if they wished to pursue a rezoning.