Adding A Bathroom To An Apartment in NYC

by | Last updated Jun 12, 2020 | Apartment Renovations, Renovations

You can add a bathroom to an apartment in NYC if you have approval from your building management or Condo / CoOp Board. This will require hiring an architect and filing for permits with the Department of Buildings. In New York City adding a bathroom is filed as an Alteration Type 2.

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. All buildings will have their own perspective and requirements.

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. Some building do not allow people to add bathrooms.

When adding a new bathroom, you will need to hire an architect. The architect will determine the work required. At our architecture firm we have done this multiple times. It is definitely doable but there is a lot of process to it. You will also need to hire a general contractor and licensed plumber to do all construction and plumbing work. This work will require inspections.

New Bathroom in Manhattan Apartment

Below is an example project where we reconfigured one bathroom and closet into 2 bathrooms and a laundry closet. We have another post you can see if you want to read about Adding a Washer Dryer to an Apartment in NYC.

This first picture is of the master bathroom in the Chelsea Apartment.

NYC Apartment Bathroom

NYC Apartment Master Bathroom in Chelsea


This next picture is the new bathroom added to the apartment.

New Bathroom Added to an Apartment NYC

New Bathroom Added to an Apartment in NYC

Check out another post we have on NYC Bathroom Design Ideas.


Requirements for Adding a Bathroom


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. Wet Over Dry is NOT a building code. It is just your own building’s internal rule, if they have this rule. Not all buildings have this rule.

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

How do you determine if you can add a bathroom to your Condo or Co-Op? 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. If you are in an elevator buildings or on the first floor of a walk up your bathrooms must be ADA Accessible. Bathrooms in these situations will need to provide certain clearances between all fixtures and the door for it to be ADA compliant. ADA stands for Americans with Disabilities Act.

We have another post that goes into more detail on ADA bathrooms and NYC Bathroom Renovation Codes.

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 this is not applicable to New 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. If you do not have a window or an exhaust this will be a larger challenge. You will need to add an exhaust in this case and if there are no existing ducts to connect to you my have a problem achieving this. You will not be abler to add a bathroom without an exhaust or window.

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 plumbing inspections. All piping requires fire stopping inspections if it passes through a fire rated assembly. 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 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 consideration when adding a bathroom.

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

Showers require drains as well and adding an elevated shower pan for draining purposes could be necessary, this can often be minimal.

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.


Smart wall mounted toilet

Smart wall mounted toilet in a concrete bathroom we renovated in the Financial District


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.


Contact Fontan Architecture


Source: NYC DOB

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.