Basement Apartment Conversions
The legalization of basement apartments is a policy issue that lives at the intersection of housing, climate change, and social justice. As an accessory dwelling typology, they provide an affordable unit without public subsidy; they expand housing choice without significantly altering the physical character of the neighborhood; and they improve access to parts of the city that have historically excluded low-income New Yorkers.
Why Basements?
Basement apartments have always been a critical supplement to New York City’s housing stock. They are particularly advantageous because they create new rental units without the cost of acquiring land, rent for less than comparable above-grade units, and provide homeowners with a source of revenue to help pay a mortgage, maintain the property, or cover other expenses. Basement apartments offer housing options and financial stability to underserved groups such as new immigrants, elderly residents aging in place, and multi-generational households.
Most of New York City’s basement apartments exist within the informal market, due to the financial and regulatory barriers faced by homeowners wishing to undertake a conversion. Keeping these arrangements under the radar jeopardizes the safety and security of both tenants and homeowners, empowering neither with leasehold rights and allowing the potential for unsafe living conditions. Streamlining a pathway for the conversion of basements into safe, legal apartments would make these housing arrangements safer and more stable, for homeowners and tenants, and add to the housing stock during an affordable housing crisis.
For years, CHPC has been a leader in research and advocacy on basement conversions in New York City. In 2016, CHPCs Hidden Housing study found between 10,000 and 38,000 potential basement apartments citywide that could be brought into safe, legal use without changing the Zoning Resolution. Hidden Housing and CHPCs Basement Conversions Regulatory Checklist directly informed legislation passed by the New York City Council in 2018, creating the Basement Apartment Conversions Pilot Program (BACPP).
In 2019, CHPC hosted a half-day symposium called Housing Innovation Lab: Basements to explore innovative solutions in fire protection, lighting, and ventilation. When the pandemic constrained the government’s ability to subsidize housing programs, CHPC published the Basement and Cellar Regulator Reforms brief that proposed more than a dozen policies addressing some of the most challenging barriers that homeowners face when undertaking a conversion. In 2021, the New York City Council passed Int. 2261, which included two building code reforms submitted by CHPC to facilitate conversion. Currently, CHPC continues to work with the NYC Department of Housing Preservation and Development to evaluate the ongoing BACPP and its potential to be scaled citywide.
CHPC continues to illuminate the regulatory, administrative, and financial barriers that prevent homeowners from undertaking a conversion.
Featured publications
Basement Apartment Conversion Pilot Program Interim Report
The focus of this interim report is to describe why properties did or did not advance through the pilot and to outline additional changes that would enable the implementation of an effective legalization program at scale.
Home Truths
How well is the housing in low-density districts meeting the needs of residents? CHPC asked 805 New Yorkers to find out.
From Lot to Neighborhood to City: An Action Plan for Basement Flood Safety & Stormwater Equity
CHPC’s new report on basement flood safety & stormwater equity explores possible interventions designed for city-, neighborhood-, and lot-level accountability.
Regulatory Reform for Basement Apartments: Policy Brief
In this policy brief, CHPC identifies regulatory reforms that could facilitate basement apartment conversions by making them safer, easier, and more affordable.
BASEMENTS ALMANAC
CHPC’s Basements Almanac is a compendium of best practices and technology to help make basement apartments safer and more habitable.
Hidden Housing
In the Hidden Housing report, CHPC makes the case for basement apartments in New York City and provides six key recommendations for how a basement conversion program could be implemented
Basement Apartment Regulatory Checklist
CHPC created the Basement Apartment Regulatory Checklist as part of its ongoing efforts towards making it feasible for New York City homeowners to rent out a safe and lawful apartment in the basement of their homes.
Illegal Dwelling Units: A Potential Source of Affordable Housing in New York City
CHPC partnered with Chhaya CDC, a community based organization working with new immigrants in the borough of Queens, to estimate the number of such units in two specific geographic regions and to assess the potential for owners to legalize existing units.
Read about our Housing Innovation Lab: Basements event
Housing Innovation Lab: Basements
In February 2019, CHPC hosted Housing Innovation Lab: Basements to explore how best practices and new technology to enhance light, air quality, and fire safety could improve the safety and habitability of basement apartments.
Explore CHPC’s interactive map show the distribution of potential as-of-right basement apartments
Testimony and impact
Regulatory Barriers to Basement Legalization in NYC
Pilot for Basement Conversions
Flood Resilience Zoning Text Amendment
Initiative Sponsors
