NYC gave renters the right to air conditioning by 2030. Co-op subletters are the landlord. Sellers don't have to say so.

NYC Local Law 23 of 2026, titled "Cool Homes For All," took effect January 17, 2026. By June 1, 2030, every residential landlord in the city must provide a functioning cooling system in sleeping areas when a tenant requests one. For co-op shareholders who sublet their apartments, that obligation belongs to them as the sub-landlord. When they sell their shares, New York Real Property Law § 461 does not require them to say so.

What Local Law 23 requires.

The law amends the NYC Housing Maintenance Code by adding Administrative Code § 27-2029.1. During the cooling season (June 15 through September 15), whenever the outdoor temperature exceeds 82°F, the owner of a residential unit must provide an approved cooling system capable of maintaining the sleeping area at or below 78°F, if the tenant has requested one. The equipment type is the owner's choice: a window unit, a through-wall packaged terminal air conditioner, or a central system each qualify, provided the unit meets the thermal performance standard. Compliance is not required for any building with an existing central air conditioning system that serves the entire dwelling unit. Tenant opt-in begins March 1, 2028; once a tenant submits a written request, the owner has 60 days to install a compliant system. After June 1, 2030, non-compliance is classified as a Class C "immediately hazardous" violation under Admin Code § 27-2115(f), with civil penalties up to $1,250 per day.

In a sublet co-op unit, the shareholder is the landlord.

NYC co-op corporations own the building. Shareholders hold stock and occupy their apartments under a proprietary lease. When a shareholder sublets, the occupant's landlord is the shareholder, not the co-op corporation. The NYC Housing Maintenance Code defines "owner" to include anyone who controls a dwelling unit and collects rent from its occupant. HPD's enforcement target for a Local Law 23 violation in a sublet co-op apartment is the shareholder who sublet it, not the co-op board. The board's own role in that transaction was limited to approving the sublet under the proprietary lease. Once approved, the shareholder stepped into the landlord's position. The tenant's right to request cooling by June 1, 2030 runs against that shareholder individually.

The board's no-window-AC rule is now conditional.

Many prewar NYC co-op buildings restrict or prohibit window-mounted air conditioning units. The stated reasons vary: facade integrity, water intrusion risk, aesthetic standards written into the house rules in the 1950s. Local Law 23 explicitly provides that a building rule cannot be used to prevent an owner from complying with the cooling obligation. A board that enforces a blanket window-AC prohibition against a subletting shareholder whose tenant has exercised the LL 23 opt-in is obstructing a statutory compliance duty. The carve-out is limited to the landlord-tenant context. A board can still prohibit window units in owner-occupied apartments. In buildings where sublet units and owner-occupied units share the same electrical branch circuits, that distinction creates an engineering problem the board did not choose and cannot easily price.

Electrical infrastructure is a shared cost.

A standard window AC unit draws 1,000 to 1,500 watts. A prewar NYC co-op building with 40-amp residential service per unit, common in buildings constructed before 1960, may not support that load on a circuit that also serves a refrigerator, dishwasher, and lighting. When a shareholder must install an AC unit to meet the LL 23 obligation, one of two things happens: the unit draws on existing circuits that were not designed for the load, or the building upgrades electrical service. Panel upgrades and riser extensions are capital projects. Their cost flows through common charges to all shareholders, not only those who sublet. The managing agent who scopes, bids, and oversees that work needs no license from New York State. Subletters in larger co-op buildings, where dozens of shareholder-landlords face the same 2030 deadline, can produce a coordinated infrastructure cost that was never disclosed in any document the board issued or any seller was required to deliver.

What New York does not require sellers to say.

Real Property Law § 461 is the Property Condition Disclosure Act. It requires sellers of residential real property to complete a disclosure statement covering flood risk, environmental conditions, structural defects, and systems. Subsection (2)(b) specifically excludes cooperative apartments. A seller of co-op shares has no statutory obligation under the PCDA to disclose anything about the building's physical condition or its compliance obligations. Local Law 23 falls outside the disclosure frame for a second reason: the law creates a landlord obligation, not a building defect. PCDA-style disclosures address what is wrong with the property. The obligation to provide AC by 2030 is not a defect; it is a prospective duty that attaches to the role of subletter-landlord. A buyer who purchases shares intending to rent out the unit acquires that duty. New York has no statute that requires any party in the transaction to say so before the contract is signed. The buyer's attorney can research LL 23 independently, but no rule makes that research a condition of closing.

The managing agent problem.

Local Law 23 creates ongoing administrative work at the building level: tracking which units are under sublet agreements, processing AC installation applications from shareholder-landlords, overseeing electrical work that may require DOB permits, and documenting compliance for HPD inspection. In most NYC co-op buildings, those functions are performed by the managing agent. Senate Bill S.71 (Kavanagh), the only active bill in Albany to require managing agent licensure for co-op and condo buildings, has not received a committee hearing in nine consecutive sessions. The 2027 session begins without an identified Senate sponsor for the bill. A shareholder who must comply with LL 23 in their building relies on an unlicensed intermediary to coordinate the work, approve the installation, and verify the electrical capacity. If the managing agent misjudges the load calculation, the cost arrives in the next common-charge statement, distributed to every shareholder in the building.

Bottom line.

Local Law 23 of 2026 is a genuine tenant-protection measure. The four-year phase-in gives building owners time to plan, which is the right approach for a city where most residential buildings predate central air conditioning by decades. The structural problem is not the law itself. It is the combination of three features that New York has declined to address in parallel: no seller disclosure requirement for co-op apartments, no license requirement for the managing agents who administer compliance, and no state-level mandate on boards to notify shareholders of prospective costs before they materialize in an assessment. A buyer who purchases co-op shares without knowing about Local Law 23 is not a negligent buyer. They are a buyer operating inside a disclosure framework that stops at the building's front door.

Primary sources: NYC Local Law 23 of 2026 (Int. 0994-A-2024), effective January 17, 2026; NYC Administrative Code § 27-2029.1 (as added); NYC Administrative Code § 27-2115(f) (penalty schedule); NY Real Property Law § 461 (Property Condition Disclosure Act, cooperative apartment exemption); NY Senate Bill S.71 (2025-2026 session, managing agent licensure).

Companion resources: Flood disclosure and the co-op exemption (June 24, 2026) · Local Law 33 energy grade and the seller disclosure gap (August 10, 2026) · Local Law 58 put managing agents on the clock with no license requirement (June 6, 2026) · S.71: the managing-agent licensure bill (May 18, 2026) · The NYC local-law extraction stack