Good morning, my name is Marcel Negret, Land Use Director at Regional Plan Association, an organization that researches and advocates for long-term planning across the New York City metro area. Thank you for the opportunity to testify regarding the proposed DOB rules for Ancillary Dwelling Units (ADUs).
We commend the various efforts and actions from local and state governments to support building and legalizing ADUs across New York City. This includes recent zoning changes, the One ADU state program, pilot exemptions for basement apartments from the state Multiple Dwelling Law, and new technical assistance for homeowners provided by city agencies.
While the zoning reforms adopted by the City of Yes initiative are a welcome and needed step to address the city’s affordable housing crisis, many of the specific provisions about ADUs – if left unaddressed – will maintain significant barriers that are creating confusion and limit the number of property owners interested in developing and legalizing ADUs.
An RPA analysis of the existing housing stock and zoning rules reveals that a substantial portion of the city’s single- and two-family homes will not be eligible for ADUs due to a combination of factors. Of the 565,424 total single- and two-family lots in the city, an estimated 460,087 would still be barred from adding an ADU, leaving only about 105,338 lots, or 18.6%, where an ADU is a possibility. Based on housing tenure, owner preferences, financial feasibility, insurance, and other factors, a much smaller fraction of these properties will likely materialize with an ADU.
The restrictions are not evenly distributed across building types:
Attached Buildings: The rules are most restrictive for attached buildings, with 0% of these lots (0 out of 219,902) being eligible.
Semi-detached Buildings: Only 14.0% of semi-detached buildings (22,403 out of 160,112) are potentially eligible.
Detached Buildings: The regulations are most permissive for detached buildings, with 44.7% of these lots (82,935 out of 185,410) being potential candidates for ADUs.
A deeper dive into the specific barriers shows that various zoning provisions contribute to the high rate of ineligibility. The most common barriers are those related to building type, dimensional criteria, and contextual zoning. For example, 53% of lots are likely deemed ineligible based on their building type. Dimensional criteria like lot size or setbacks will also block over half of the low-density stock from an ADU. About 18% of single and two-family lots will be restricted due to contextual zoning and historic districts. While necessary safety regulations related to fire, egress, and flood risk also apply, and in cases justified, the primary regulatory challenge to expanding ADUs are the zoning provisions related to building typology and dimensional criteria that will broadly define where they are allowed or not.
The intent behind the new initiative is clear: to increase the housing supply and provide homeowners with potential new revenue in ways that are safe and responsible. However, the practical application of these rules may mean that the number of new, legal ADUs created will fall short of the city’s ambitious goals. The stringent zoning provisions related to building types and dimensional criteria, which exclude a vast number of properties are the main factor limiting the impact of the zoning reforms. For the ADUs to truly have a transformative impact on the housing crisis, the city may need to re-evaluate the zoning rules that currently prevent most single- and two-family homeowners from creating these crucial housing units. Interagency collaboration and technical assistance will also be essential. For the implementation of the specific DOB rules in question, we recommend that the various city agencies involved (i.e., DOB, HPD, DCP, FDNY) take an expansive interpretation for the applicability of ADUs in building classes A9 and B3. This will ensure that more property owners of these building classes are considered for permitting an ADU.
