Glossary
The words the law uses, in plain language. Point at a dotted word anywhere on the site to see its definition.
- Adequate cooling
78°F or cooler indoors, measured at least 3 feet above the floor and 3 feet from exterior walls.
- Approved cooling system
A window or wall unit sized at 20 BTU per hour or more for each square foot it cools, or a central system that meets the Building Code. Either must be approved by the Department of Buildings.
- BTU
British thermal unit. Air conditioner power is measured in BTU per hour, and the law asks for at least 20 BTU per hour for each square foot of a room.
- Centrally supplied cooling
A system that sends cooled air to more than one apartment from one central place.
- Class C violation
The City's most serious housing violation category, called immediately hazardous. Under this law the owner has 14 days after the notice to correct it.
- Cooling season
June 15 through September 15 each year.
- Covered dwelling
A multiple dwelling, or a one or two family house with a tenant. Buildings the City uses for emergency temporary housing are left out.
- Covered room
A room in a covered apartment that the owner knows, or can reasonably foresee, is a permanent occupant's main place to sleep. The cooling rule applies only to covered rooms a tenant elects.
- Election (tenant request)
A tenant's choice to put a covered room under the cooling rule. Elections open March 1, 2028, and each one takes effect 60 days later.
- ENERGY STAR
A U.S. Environmental Protection Agency program that certifies energy efficient products.
- Hardship extension
Extra time an owner can ask the City for, in steps of up to two years, renewable. Grounds include financial hardship, major capital work, significant electrical upgrades, and landmark limits.
- Individual Apartment Improvement
A state rule that can raise a rent stabilized rent after work inside the apartment. An occupied apartment needs the tenant's written consent, and the increase is permanent.
Source: NYS HCR Fact Sheet #26: Individual Apartment Improvements
- Multiple dwelling
Under state law, a building rented out or lived in as the home of three or more families living independently of each other.
Source: NY Multiple Dwelling Law § 4 (definition of multiple dwelling)
- NYSERDA
The New York State Energy Research and Development Authority. It runs the incentive for owners who install window heat pumps.
Source: NYSERDA Room Heat Pump Program
- Owner (co-ops and condos)
For a condo apartment, the owner is the person who owns the unit. For a co-op apartment, it is the shareholder of record on the proprietary lease.
- Owner controlled system
A central system where the owner pays for the electricity and sets the temperature.
- PTAC
Packaged terminal air conditioner: a self contained unit that sits in a sleeve through an outside wall.
Source: ACRules: PTAC installation
- Rent regulated apartment
An apartment covered by state rent stabilization or rent control. Tenants in these apartments must consent to the cooling work and any charges.
- Window heat pump
A unit that sits in a window like an air conditioner and also heats in winter.
Source: ACRules: Window heat pumps
Checked October 22, 2026. Information only, not legal advice.
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