Pratt Center Project

Building Resilient Communities

Basement Apartments Safe for Everyone (BASE) Campaign

A community-based coalition advocating for a legal pathway to convert basement and cellars into safe, healthy and affordable apartments.


Basement Apartments Safe for Everyone (BASE) is a community-based coalition, led by Chhaya CDC, that has been working to tackle one of the most common-sense issues in affordable housing in New York: converting basements and cellars into safe, legally recognized rental units. Current estimates show more than 114,000 “informal units” citywide, referring to housing that is not legally considered a dwelling unit, but that is occupied nonetheless. Typically, these units are located in the basement or cellar of one- to three-family homes. Legal basement conversions represent a crucial strategy for maximizing existing housing stock in small homes to provide safe, healthy, and affordable housing.


Since 2006, our research and advocacy has supported BASE in advancing a proposal for these units, one that is rooted not only in technical feasibility, but in meeting a critical social need for lower-income homeowners who are under threat of foreclosure and low-income tenants, who desperately need safe and affordable places to live. In 2009, we published Housing Underground: A Refuge and Resource, which documents the neighborhoods with the greatest need and articulates some of the basic components of a successful policy in New York City. These include:

  • Working closely with community-based stakeholders who know the community best, and have deep relationships and expertise with homeowners
  • Maximizing the universe of eligible units to include 2-family homes
  • Incorporating affordable housing mechanisms to protect existing tenants and prevent displacement
  • Working neighborhood-wide in communities with high numbers of informal units to make sure that infrastructure planning and service levels take into the account the actual population of the neighborhood

Mayor de Blasio endorsed the effort in his Housing New York Plan in 2014, but in response to local organizing, deepened his commitment substantially when he committed $12 million to explore and implement a pilot as part of the 2016 rezoning of East New York. Pratt Center worked closely with Cypress Hills LDC and other community-based partners, agencies, Council Members, and the mayor’s office to shape the design of a pilot program to fulfill this commitment.

The East New York Basement Apartment Conversion Pilot is just one step on the way to meeting the BASE Campaign’s goal of a citywide basement conversion program. We will continue to advocate with and support our community-based partners in the fight to see communities across New York City benefit from the opportunity that basement apartments bring to keep housing affordable and neighborhoods stable.

Over the years our work has been supported by distinguished alumni, students, and professors from Pratt Institute’s School of Architecture, which houses the Graduate Center for Planning and the Environment.  In particular, Louis Céspedes (who served as a Pratt Center Fellow in the 1990s early in his career!) and Deborah Gans have been extremely generous with their expertise and critical to our efforts to document existing basements and cellars and craft solutions to retrofit them that comply with applicable codes.