Adding a Bedroom To an Apartment

by | Last updated May 19, 2024 | Apartment Renovations, NYC DOB, Renovations

Can you add a bedroom to an apartment in NYC?

In NYC, you will need a permit to add a bedroom or change the number of rooms in an apartment or house. Bedrooms and habitable spaces have room requirements regarding size, dimensions, windows, accessibility, and fire protection. Adding a bedroom to an apartment involves many code issues, planning, and design.

I am Jorge Fontan, an architect in New York and owner of Fontan Architecture, an NYC-based architecture firm. We get many inquiries from people wanting to add a bedroom to an apartment. Adding a bedroom is a relatively common practice. Let’s discuss some rules and protocols for adding a bedroom to your apartment. The rules listed below are based on New York City regulations.


Adding A Bedroom / Adding A Room

If you live in an apartment building, you will want to ensure your Condo, Co-Op Board, or management company has no objections to changing the number of bedrooms in your apartment. All renovations must be approved by your building’s board and the Department of Buildings. You can read our article on Alteration Agreements for more information on this process.

The first step in adding a room will be to hire an architect. The architect will determine the legality of the work. In New York City, your architect will file an alteration with the Department of Buildings (DOB).

Adding a bedroom to a NY apartment

Bedroom in a Brooklyn Apartment we renovated.


Rules For Bedrooms and Living Rooms

There are many building codes for rooms in a residential space. The following is a brief synopsis of some of these regulations within the New York City Building Code and the Multiple Dwelling Law. Dining rooms, kitchenettes, and bathrooms have different rules that we won’t be addressing in this article. The codes set rules for habitable rooms which are:

“All rooms and spaces within a dwelling unit in Group R or I-1, including bedrooms, living rooms, studies, recreation rooms, kitchens, dining rooms, and other similar spaces”

Another post we wrote goes deeper into NYC Code requirements for habitable space if you want to learn more. All new rooms and existing rooms must comply with the following:


Minimum Room Size:

  • Rooms must be a minimum of 80 square feet.
    • One room must be at least 150 square feet.
    • Do not count closets or wall thickness for the floor area of rooms. Room areas are net measurements, not gross.
  • Rooms must have a minimum height of 8 feet.
  • The room width and depth must have a clear space of 8 feet as its minimum dimension.
  • For bedrooms in an apartment with three or more bedrooms, half the rooms can have a minimum dimension of 7 feet.
      • By half the rooms: we round down, so if there are three bedrooms, one can be 7 feet wide.
    • The bedrooms that are 7 feet wide still need to be 80 square feet minimum.
  • Rooms cannot have a space more than 30 feet from a window.
    • With some exceptions 


Natural Light and Air for Legal Rooms:

  • Each room must have at least one window.
  • The window must be at least 12 square feet, or it does not count for natural light and air.
  • The total aggregate window area, must be at least 10% of the room floor area for natural light.
    • For example, if you have a 240 square foot room, you need 24 square feet of window. You can have (2) 12 square foot windows.
    • If your room is less than 120 square feet, you still need a 12-square-foot window.
    • For a dining room, the rule is 1/8 the floor area.
  • You need half the required light for Natural Air, so 5% of the room floor area. When the windows are all open, the open area is 5% of the room floor area.
  • Windows on a shared property line do not count unless you have a legal agreement with your neighbor approved by the DOB, such as a zoning lot merger. The windows must comply with all required clearances.
  • The top of at least one window must be at least 7 feet off the floor.


General Room Requirements:

  • If your building is required to be handicap accessible, then the new rooms must all be ADA compliant.
  • You will need to get a permit.
  • Dining rooms, bathrooms, and kitchenettes (under 80 square feet) have different rules.
  • Before filling with DOB, you must get approval from your Co-Op, condo, or management company.
Adding a room to a Chelsea loft for a study

Adding a room to a Chelsea loft for a study


Adding a Room in NYC

This article reviewed some basic concepts concerning adding a room in NYC. As an architect, I study NYC DOB rules and regulations, but these are complicated and quite involved issues. This post does not assume to cover every possible issue or condition but provides a general overview of the topic.


Thank You for reading our post on Adding a Bedroom to an Apartment.

I hope this article was helpful to you. If you would like to speak with an architect about a potential project you are planning, contact us at Fontan Architecture directly.


Contact Fontan Architecture


Jorge Fontan

Jorge Fontan

This post was written by Jorge Fontan AIA a Registered Architect and owner of New York City architecture firm Fontan Architecture. Jorge Fontan has earned 3 degrees in the study of architecture including two degrees from the City University of New York and a Masters Degree in Advanced Architectural Design from Columbia University. Jorge has a background in construction and has been practicing architecture for 20 years where he has designed renovations and new developments of various building types.