Adding A Bathroom NYC

Adding A Bathroom To An Apartment in NYC

(Last Updated On: May 26, 2019)

Adding a bathroom in NYC is allowed by some buildings and not allowed by others. If you are planning to add a bathroom check with your building management first. You will need to consult with an architect in order to see if it is possible and to determine the extent of work required.

We get lots of inquiries from people who want to add a bathroom to an apartment. Some buildings do allow this. There are rules and protocols for adding a bathroom to your apartment. The rules listed below are based on New York City regulations and individual building management rules we have encountered in the past.

This work will require a building permit Alteration Type 2 or Alt 2.


Adding A Bathroom

Firstly, it is important to check with your Condo, Co-Op Board, or management company about the rules they have for adding a new bathroom in your apartment. You will need to understand your building rules and Alteration Agreements.

When adding a new bathroom, you will need to hire an architect. The architect will determine the legality of the work and in New York City your architect will file an Alteration Type 2 with the Department Of Buildings (DOB). You will also need to hire a general contractor and licensed plumber to do all construction and plumbing work. This work will require inspections.

Wet Over Dry Rule

“Wet Over Dry” in a building means having a wet space such as a kitchen or bathroom over a dry space in the apartment below such as a bedroom or living room. The “No Wet Over Dry” Rule is a building management rule specific to certain buildings. This rule states that you are not allowed to create a wet space over a dry space below as per your Co-Op or Condo Board Regulations. In the case where the new bathroom would be over a bedroom to the downstairs apartment that would be a wet over dry condition. This is not a building code, but it is a rule that some buildings have in place. You should check with your building managing agent or board to see if they impose this rule on your building.

Requirements For Adding a Bathroom To an Apartment

So how do you determine the legality of adding a bathroom ? How do you get adding a bathroom approved by DOB? The following rules are defined by New York City Building Code and Multiple Dwelling Law.

Bathroom Size

A minimum square footage is not set forth for a bathroom, rather it is regulated by accessibility in elevator buildings or on the first floor of walk ups. Bathrooms in these situations will need to provide certain clearances between all fixtures and the door for it to be ADA compliant.

ADA Accessible Bathrooms

The NYC building Code has set forth clearance regulations between and around fixtures as well as door requirements. The fixtures themselves have to be ADA listed by the manufacturer. There are three types of accessible bathrooms: Type A, Appendix P, and Prototype Bathrooms. Depending upon your apartment, you may be allowed to add any of the three. They vary in clearance requirements.

Type A is the largest, it has a 5’ turning clearance for wheelchairs. If you have one Type A bathroom in your apartment none of the other bathrooms are required to be accessible. All the fixtures must be ADA rated and provide clearances as per ADA requirements.

Appendix P is smaller, it has clearances for spaces between, around. and in front of the fixtures.

Prototype Bathrooms, are pre-approved bathroom layouts provided by NYC, which are all complaint for certain existing buildings.

New Buildings or buildings built after March 13, 1991 must have Type A or Type B bathrooms. Prototype bathrooms are only allowed in buildings first occupied before March 13, 1991 in NYC.

Bathroom Ventilation Requirements

Proper ventilation is required for all bathrooms. For NYC proper ventilation consists of having either a window or a mechanical exhaust in the bathroom. If the location you are planning to put your new bathroom doesn’t have a window, you can connect to the exhaust in another bathroom.

Plumbing Work and Inspections

All plumbing work is to be done by a licensed NYC Plumber. Before signoff on work you will have to pass a plumbing inspections. All piping requires fire stopping inspections. the DOB will have a rough pluming and finish plumbing inspection. Make sure your contractor for the bathroom renovation is on top of inspections. Plumbing inspections are in my experience one of the most common problems for getting signoff upon completion of construction.

Additional Considerations for your new bathroom.

There are also other things to take into mind when adding a bathroom.

Toilets require you to cut through the floor slab to run your drain, but if you get a wall mounted toilet you can run plumbing through the walls and not disturb the slab below.

Showers require drains as well and adding an elevated shower pan for draining purposes could be necessary.

The new bathrooms should have a water proof membrane and be built with mold resistant materials.

One of the most common bathroom trends I have noticed is that people are giving up on tubs. More and more people are doing showers over tubs and replacing existing tubs with showers. You may want to see another post we wrote on bath to shower conversion.


Adding a Bathroom Requirements

In this article we reviewed some of the basic concepts with regards to adding a bathroom. This post does not assume to cover every possible issue or condition, but provide a general overview of the topic.


Thank You for reading our blog post on adding a bathroom to an apartment in NYC.

Please feel free to leave questions or comments below. We hope this was helpful if you would like to discuss a specific project please contact us directly. We wish you the best of luck adding or renovating your bathroom in NYC.


  • Lisa Ritter-kahn

    March 23, 2019 9:10 pm

    Hi your article was very straightforward.
    I have one question. We have purchased a coop in nyc on the first floor of a pre war building. The building entrance is not Ada compliment. We have one full bath and one small powder room. We would like to leave powder room alone. We would like to add shower completely separate that would be Ada compliant. Would this be allowed? Thank you

  • Carolina Simon

    March 28, 2019 1:01 am

    Hi George,

    Thank you for the article. I live in a coop that has an existing master bathroom and what used to be a maid’s toilet room. I would like to turn that into a full wet room with sink, shower and toilet.
    Do I have to make this bathroom ADA type A or B or can it be a prototype? And what is the prototype?
    Thank you!

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