So What is the Minimum Size of a Dwelling Anyway?

By Brian Redlein

(Update:  As of the March 22, 2016 rezoning Quality Housing regulations no longer requires dwellings to have a minimum size.  The minimum size of a dwelling in the vast majority of instances now is determined by the Building Code.)

So called “micro-units” have been coming to the fore recently.  With housing demand through the roof and affordable supply more constrained than ever, the City is increasingly looking towards downsizing to meet future housing needs.  The problem is, in new buildings dwellings usually need to be a minimum of 400 square feet. But where does this number come from?  The answer is more complicated and nuanced than most would realize.

In real estate, square footage determines price so even in the cheaper parts of the City a 400 square foot condo dwelling could easily cost a relative fortune.  So for single people or couples with no concept of privacy capable of living in a shoe-box studio, the City is increasingly looking towards dwellings that fall below the 400 square foot number.  The trouble is on most development sites in Manhattan the zoning simply does not allow it.

The Quality Housing Program was created as a response to Open Space Ratio rules that governed residential building design in the early 60’s – when the modern Zoning Resolutions first came into force.  For those of us who remember the 60s and 70s think of Open Space as the Robert Moses approach to city planning, whereas Quality Housing is more the Jane Jacobs approach.  The Open Space rules rip pages from Le Corbusier’s Ville Radieuse proposal for Paris that was popular with city planners all across the country as they scrambled to provide isolated residential-only towers in parks in response to crowded tenements.  One need look no further than the mega-block developments of Sty-Town or Coop City to see Open Space Ratio zoning at work.

Quality Housing is a more contextual approach and on small zoning lots it’s really the only approach available to designers as it allows the residential portions of a building to abut the neighbors without requiring them to be isolated from other buildings by large open spaces.  In contextual districts, marked by a letter at the end of the district (such as R8B vs R8) Quality Housing rules are mandatory and there’s no way around them.  Quality Housing mandates dwellings be a minimum of 400 square feet and to go any lower requires special approval from the City.  For those designers able to work under Open Space rules dwellings can be smaller.  Worth noting however is that in lower density zoning districts (R3-R5) the minimum size of a dwelling is 300 square feet with no exceptions.

The absolute minimum size of a dwelling unit isn’t actually defined in the Housing Administration Code, NYC Building Code, or even the Multiple Dwelling Law of New York State, but the minimum room size is.  New Buildings fall under the 2014 Building Code, which demands at least one room in a dwelling unit must be a minimum of 150 square feet with other rooms allowed to be 80 square feet.  So theoretically it is possible to go smaller than 400 square feet provided there’s a handicapped accessible bathroom and still be compliant with the 2014 NYC Building Code, provided of course you were under Open Space zoning rules in a higher density district.

Most of us on smaller lots are stuck with Quality Housing rules so the 400 square foot rule is the standard.  Whether or not the 400 square foot rule will ever will be changed will be a matter of debate I’m sure as the whole point of Quality Housing was to provide decent homes for families that needed more than shoe box studio of living room.  The question that vexes the City is a hard one – are these rules relevant in a day and age when most of the City’s workforce is effectively priced out of the housing market?