Are Basement Apartments Legal in New York?

In New York City, below-grade stories are either cellars or basements. A cellar is a story where at least 50% of the height from the finished floor to ceiling is below street level. A basement is a story where at least 50% of the same height is above street level.

The Multiple Dwelling Law (MDL) of New York State, which applies to structures with three or more units, forbids any residential use in cellars. However, if the unit conforms with all other statutory criteria, it permits residential use in basements, including constructing an ADU (Accessory Dwelling Unit).

The Multiple Dwelling Law on basements and cellars in New York State guides all landlords, tenants, and any other building owners or occupants for safety purposes.

Basement Apartment

How to tell if an NYC basement apartment is legal

The height of basements and cellars above the curb is different. A cellar has less than half of the height above the curb than a basement, which has at least one-half of its height above it. If a cellar has any windows, they are typically too small for an adult to pass through.

The Department of Buildings (DOB) must approve the basements and cellars of residential buildings of all sizes before they can be legally rented out. So occupied, and only if they fulfill the minimal light, ventilation, cleanliness, and egress standards. 

Check the Certificate of Occupancy to determine whether the basement you want to rent is legitimate. One- and two-family homes’ basements can only be inhabited legally in the following situations:

  • The room conforms with the minimum room size and other requirements of the Housing Maintenance Code for rooms that are not in the cellar or basement.
  • The ceiling must be at least 7 feet high.
  • If the Health Product Declaration (HPD) deems that the subsoil conditions on the lot call for it, the walls, up to ground level, must be damp- and waterproof.
  • Only members of the family or families residing in the home are allowed in the basement.

One-family homes’ basements can only be rented out legally if the following requirements are satisfied:

  • The minimum room size by the Housing Maintenance Code should be met.
  • The ceiling must be at least 7 feet high.
  • If HPD deems that the subsoil conditions on the lot call for it, the walls, up to ground level, must be damp- and waterproof.
  • Only one family is living in the basement; there are no borders.
  • There must be a window in every room.
  • A needed window in a room cannot have its sill higher than 6 inches above the bottom of any required open space.

However, a two-family house’s basement cannot be legally rented out if it is in a two-family place. As a result, the structure would lose its two-family status and become a multiple-family house with three families or more.

This will necessitate a new Certificate of Occupancy from the Department of Buildings. Its safety is also determined by whether the basement was constructed with the building or afterward.

Dangers of illegal basements

Some of the dangers you’re likely to face with basements include the following:

1. Eviction

Illegal apartments do not adhere to building and fire rules regarding gas lines, water, and heating systems. In addition, the landlord or law enforcement officials may be contacted to have you removed from the property if a third party declares the basement residence illegal.

2. Loss of property

You are constantly in danger of being sued for your possessions. However, the amount of documentation required, the penalties, and the harm done are not worth having an illegal basement. 

3. Loss of claim

If an unforeseen catastrophe results in the failure of the basement, homeowners might be unable to get insurance benefits for the rental property. Most plans provide that homeowners must notify the insurer of any house modifications. 

If the insured doesn’t keep within housing compliance guidelines by constructing an illegal basement, the insurance company may not compensate them when they’re sued for loss or liability. 

4. Safety

There is a purpose for the laws governing legal permits. This is the justification to protect people within and around the unit from potential dangers or mishaps. The inhabitants of the basement flat are in trouble since an illegal unit might not always comply with the regulatory authorities’ fundamental standards.

For instance, if your apartment does not adhere to electrical and fire safety rules and a flood or fire occurs, the occupant is in danger of dying or suffering irreparable harm.

5. Peace of mind

Finally, you pay the price for your peace of mind due to the weight of these consequences. Why put yourself through all this bother when you may have a legal basement apartment with all the necessary governmental licenses?

What are the legal penalties for illegal basements?

HPD and DOB have the authority to do a basement or cellar occupancy inspection. In addition, each agency has the power to issue vacate orders, which require the occupier of an illegal location to depart on violations of illegal occupancy conditions. 

The occupier is informed that HPD can provide relocation services if either agency issues a Vacate Order. In addition to providing relocation assistance to residents who receive these services, property owners will be liable for any fees incurred by the agency. These expenses might be substantial.

If HPD issues a Vacate Order, the organization will inform the owner and occupants about it and give a date for when it will go into effect. On the day of enforcement, HPD will conduct a second inspection of the property to ensure the illegal basement or cellar apartment is empty and properly sealed.


You can avoid worrying about any of the concerns above by consulting professionals and obtaining the necessary regulatory organization approvals. An illegal basement apartment could cost a pretty penny, but it would save you a lot of trouble later.

Frequently Asked Questions

What is considered a legal basement apartment in NYC?

For an apartment to qualify as a legal basement apartment in New York City, at least half of the space must be above the curb level. This is set by the state’s Multiple Dwelling Law and the New York City’s Zoning resolution.

How do I report an illegal basement apartment in NY?

You can report an illegal basement apartment in your area in New York by calling 311 then following the prompts, or submitting a complaint online.

How do I evict a tenant from an illegal basement apartment in NYC?

To evict a tenant from an illegal basement apartment in New York City, follow these steps:

  • Verify whether the basement apartment is legal or not
  • Inform the tenant
  • Get the opinion of an attorney
  • File a court petition
  • Attend the required court hearings
  • Obtain a warranty of tenant eviction
  • Follow the legal steps to evict them as per the warranty of eviction.

Always follow the right procedure to avoid incurring extra costs.

Leave a Comment

Your email address will not be published. Required fields are marked *