Ask an Expert

My neighbor's AC looks unsafe. What are the rules for installing a window air conditioner in NYC?

By Alanna Schubach  | July 19, 2021 - 12:30PM

Depending on the height of the building, your neighbor may required to install brackets for their AC.


My upstairs neighbor's air conditioning unit is not on brackets and I'm wondering if that's safe. It's also dripping on my window AC, which is annoying. Are there any laws regarding window AC units? Is there a penalty for not using brackets, and do the rules differ for a co-op, condo, or rental?

There are legal requirements for air conditioning installation, and buildings often have their own sets of rules, too, our experts say.

"Local Law 11 requires window ACs in buildings six stories or more to be installed with a mounting support bracket on the exterior," says Michael Fasulo, a partner with Rodman Paul Architects. "Co-ops, condos, and rental managing agents also often have rules regarding supports, and these will vary by building." 

If your neighbor is on the sixth floor or higher and has not installed their air conditioning unit correctly, they're violating Local Law 11, the city code that deals with building exteriors. The law also requires owners of multi-unit buildings six stories and higher to have their facades inspected every five years, and they are fines if the inspection turns up any violations. If this applies to your building, you could contact management and let them know they could be facing penalties because of your neighbor's air conditioning unit. 

And if you are in a co-op or condo, you could reach out to the board to ask whether there are building-specific rules for an AC installation, in which case your neighbor may be required to have their unit mounted on brackets. 

As for the dripping, that's an easier fix for the owner.

"ACs generate condensation as part of the cooling process. The machines are usually designed to send the condensation in the form of dripping water away from the building out the back end of the unit," Fasulo says. "If the unit isn’t leveled, the condensation may drain backward toward the building which can run into the walls and leak around the heads of windows. If this is the case, the unit would need to be adjusted to drain however the manual describes." 

You could speak to your neighbor about your concerns and let them know that getting the AC installed properly is in their own interest, too, as there are potential pest issues involved. 

"With window AC units, you want to block the gap between the unit and window sill or frame to prevent birds from nesting and bird mites coming in off the nest," says Gil Bloom, president of Standard Pest Management. "This is best done at the time of initial installation." 

If all else fails, you could deal with the dripping issue yourself by investing in a drip cushion, which dampens the sound and could make your neighbor's AC less of a nuisance to you.

Trouble at home? Get your NYC apartment-dweller questions answered by an expert. Send your questions to [email protected].

For more Ask an Expert questions and answers, click here.


Alanna Schubach

Contributing writer

Contributing editor Alanna Schubach has over a decade of experience as a New York City-based freelance journalist.

Brick Underground articles occasionally include the expertise of, or information about, advertising partners when relevant to the story. We will never promote an advertiser's product without making the relationship clear to our readers.