What Is the Core Billing Problem With Mini Split Cooling Billing in a Master-Metered NYC Co-op?

A heat pump does one thing that splits a traditional billing arrangement in two: it provides both heating and cooling from a single outdoor unit and refrigerant circuit. In a conventional NYC building, heating is the owner’s expense and cooling is the resident’s expense because the systems are physically separate. A gas boiler heats; a window AC cools. Install a mini split heat pump and that clean line disappears.

HPD’s Electric Heating Policy generally does not allow shifting heating costs onto residents or tenants. Resident-paid heating is only permitted in specific circumstances and requires prior HPD approval. So if your master-metered co-op or rental puts a heat pump on the house meter and bills residents for all electricity the unit draws year-round, you are almost certainly in violation. The fix requires designing the metering strategy before installation, not after.

What Kind of Building Are You In? Master-Metered vs. Directly-Metered vs. Submetered

Before choosing a billing approach, confirm your building type. The distinction controls which rules apply and which options are on the table.

• Master-metered: One Con Edison meter serves the entire building. The overall monthly bill, including a demand charge based on peak kilowatts, is paid by the owner and then allocated to shareholders or tenants by shares, square footage, or flat allocation embedded in maintenance charges. This is the most common configuration in pre-war NYC co-ops.
• Directly-metered: Con Edison installs a separate meter for each apartment and bills residents individually at retail rates. Most post-war condos and newer rentals are wired this way. If your residents already get a Con Edison bill, you are directly metered.
• Submetered: A single master meter serves the building, but landlord-owned submeters measure each apartment’s consumption. The owner bills residents based on actual usage at no more than the retail rate they would have paid Con Edison directly. New York State PSC Part 96 governs this setup, and since December 2012, a co-op or condo board can vote to convert to submetering unilaterally without shareholder approval, provided the board files the required petition with the PSC.

If you are unsure which type you are in, pull the most recent Con Edison bill. A single account number covering the whole building equals master-metered. Multiple account numbers, one per unit, equals directly-metered. A single account with a separate billing agent charging residents equals submetered.

Why Does HPD’s Electric Heating Policy Complicate Things for Heat Pumps?

HPD’s policy is straightforward in principle but creates an engineering problem in practice. Heating costs cannot be shifted to residents without prior HPD approval. A heat pump delivers both heating and cooling from one system, so a single meter on that system cannot legally be billed to the resident in full, because part of the energy consumed is heat.

The HPD/NYSERDA solution is the Energy Apportionment System, or EAS: a hardware-and-software layer that separates measured cooling consumption from measured heating consumption so residents can be billed only for cooling. Many leading heat pump manufacturers provide proprietary EAS products. Third-party options such as Intesis are also available and can work across multiple brands.

Shifting heating costs to residents is explicitly prohibited for rent-stabilized and rent-controlled apartments. For market-rate rentals, prior HPD and HCR permission is still required. For co-ops, the board has more flexibility, but the building must still document compliance with the Electric Heating Policy. The safest path in any building type is to treat heating as an owner expense and bill residents only for confirmed cooling consumption through an EAS.

What Is an Energy Apportionment System (EAS) and What Does It Actually Contain?

An EAS is not software alone. The physical heart of the system is a factory-assembled apportionment panel that contains voltage inputs for the outdoor units, utility-grade power meters, current transformers, a pulse-input controller to monitor usage signals from both indoor and outdoor equipment, and a communications module to relay data. The panel draws power from the main house electric panel.

Metering works by monitoring the expansion valve position on each indoor unit to calculate the fraction of refrigerant flowing to that unit at any moment. Current transformers record watt-hours at the outdoor unit. The EAS then apportions outdoor unit electricity to each indoor unit based on that refrigerant fraction. On most platforms, a single expansion controller handles up to 50 indoor units, and additional controllers can be daisy-chained for larger buildings.

Central VRF systems and larger three-phase multi-split systems generally have a native protocol that differentiates cooling from heating energy. Single-phase mini-split and multi-split systems can use the same hardware, but the specific indoor-outdoor combination must be reviewed by the manufacturer to confirm functionality before specifying the EAS.

Which Metering Typology Fits Your Building? A Decision Matrix

HPD and NYSERDA identify six main configurations for heat pump billing in multifamily buildings. The table below maps them to building size, billing approach, and cost tier so you can identify your realistic options quickly.

For the typical NYC co-op under seven stories, the two realistic split-billing paths are: (1) mini-split on apartment meter where resident-paid heating has been cleared through HPD, or (2) mini-split on house meter with an EAS so the owner absorbs all heating cost and bills the resident only for summer cooling. Most co-op boards choose option 2 to avoid the HPD permitting complexity of option 1 and to protect shareholders from unpredictable heating bills.

Buildings over seven stories generally need a three-phase commercial VRF system due to refrigerant pipe length limits. The billing logic is the same but the EAS must be sized for a commercial VRF outdoor plant rather than a residential multi-split. If you are in a large pre-war co-op in the West Village or Morningside Heights and exploring a full electrification retrofit, the VRF path with centralized EAS is the design your engineer should be specifying. See our guide on keeping steam radiators while adding mini splits under Local Law 97 for a hybrid approach that sidesteps the full VRF cost.

What Does Submetering Actually Cost in a Master-Metered NYC Building?

Cost is the most overlooked variable in the billing conversation, and it can flip the math entirely. There are two tracks: utility-administered hybrid metering and third-party submetering service.

The critical caution: in a mild NYC summer, a single-zone mini-split cooling a 600-square-foot apartment may consume only $15–$30 worth of electricity per month during June, July, and August. If the metering service costs $15–$20 per month all year, the annualized metering fee can equal or exceed the cooling cost you are trying to recover. Run the cost-effectiveness analysis before committing to any submetering arrangement. For smaller buildings with five to ten units, owner-paid cooling (folding the cost into maintenance) may be simpler and cheaper than standing up a formal submetering program.

The master-metered bill also includes a demand charge based on peak kilowatts drawn by the building at any moment. Smart heat pumps that can curtail load during a Con Edison or NYISO event day reduce that peak, which reduces the demand charge on the whole building’s monthly bill. This is a real financial benefit that often goes uncounted when boards debate submetering. Our guide to the Con Edison heat pump rate plan options covers how the rate structure affects your master bill.

How Does the Submetering Process Work for a Co-op Board?

Converting a master-metered co-op to submetering for heat pump cooling billing requires a PSC petition. The process is more involved than simply installing hardware, but the board does not need shareholder approval to proceed. Here are the steps in sequence:

• Step 1 – Metering strategy design: Work with your HVAC installer and electrical engineer to select the typology (see the decision matrix above) and confirm which EAS the manufacturer supports for your specific mini-split or VRF model.
• Step 2 – Cost-effectiveness analysis: Compare projected cooling energy per apartment against annual metering service cost. If metering cost exceeds cooling cost, consider owner-paid cooling or dual-circuit wiring instead.
• Step 3 – PSC petition filing: File a petition under Part 96 of the PSC regulations. Include consumer-protection disclosures, the metering hardware spec, billing methodology, and rate cap documentation confirming residents will not be billed above the Con Edison retail rate.
• Step 4 – EAS installation: Have a licensed electrician install the factory-assembled apportionment panel, wire current transformers to each outdoor unit, and commission the communications module on the building LAN.
• Step 5 – Software configuration and billing setup: Configure the EAS software to separate heating consumption from cooling consumption and generate per-apartment cooling invoices. Establish a billing period, typically May through August, and a policy for absorbing minor shoulder-season cooling costs rather than billing for fractional amounts.
• Step 6 – Annual audit: Review metered data annually to confirm apportionment accuracy and update the billing rate if Con Edison tariffs change.

If your building is also considering a broader electrical upgrade to support the heat pump load, our guide on Con Edison electrical service upgrades for heat pumps covers load letters, timelines, and costs that run in parallel with the metering setup.

Common Mistakes to Avoid

• Putting the heat pump on the house meter and billing residents the full draw. This shifts heating costs onto residents without HPD approval and violates the Electric Heating Policy for rent-stabilized units outright.
• Specifying an EAS before confirming manufacturer compatibility. Not every indoor-outdoor combination supports the native EAS protocol on single-phase systems. Check with the manufacturer before design is finalized.
• Skipping the cost-effectiveness analysis. A $15–$20/month utility metering fee can wipe out the cooling cost recovery entirely for smaller apartments. Run the numbers first.
• Assuming the PSC petition is optional. A board can decide to submeter unilaterally, but the petition and consumer-protection filing with the PSC are still legally required before billing begins.
• Billing year-round instead of seasonally. Residents can only be billed for cooling, not heating. Billing for heat pump consumption in January is a direct violation regardless of what the EAS reports.
• Treating room heat pumps and split-system heat pumps identically. Room heat pumps (PTHPs, window heat pumps) are only allowed on apartment meters in co-ops, not rentals, and require separate HPD permission. Split systems follow a different pathway.
• Installing a VRF system in a building under seven stories without weighing the alternative. For sub-seven-story buildings, mini-splits with a proprietary EAS often cost less to install, use less energy, and are simpler to maintain than a large commercial VRF with the same billing capability.

Frequently Asked Questions

Can a NYC co-op board bill shareholders for heat pump cooling without HPD approval?

Yes, for cooling only, provided the building has a compliant submetering arrangement approved by the PSC and an Energy Apportionment System that physically separates heating consumption from cooling consumption. The board cannot bill for heating without prior HPD approval, and shifting any heating cost to rent-stabilized or rent-controlled residents is prohibited regardless of approval.

What is an Energy Apportionment System and who makes one?

An EAS is a factory-assembled panel containing utility-grade power meters, current transformers, a pulse-input controller, and a communications module. It apportions outdoor unit electricity to each indoor unit based on the fraction of refrigerant flowing to that unit at any moment. Most major heat pump manufacturers offer a proprietary EAS for their equipment. Third-party options like Intesis are also available and can be used when the manufacturer’s native system is not compatible with the installed equipment.

How do I know if my NYC building is master-metered?

Check the Con Edison bill. If there is one account number for the entire building and the owner or managing agent pays it, the building is master-metered. If individual shareholders or tenants receive their own Con Edison bills, the building is directly-metered. If shareholders receive a separate bill from a third-party billing agent rather than Con Edison directly, the building is submetered.

Is submetering for heat pump cooling worth it financially in a small NYC co-op?

Not always. Third-party submetering services cost roughly $4–$8 per apartment per month, and utility-administered metering can run $15–$20 per apartment per month. In a small building where summer cooling draws only $15–$30 per unit monthly, the metering cost can match or exceed the cooling revenue recovered. For buildings with fewer than ten units, owner-paid cooling folded into maintenance charges is often the simpler and more cost-effective path.

Do rent-stabilized apartments in a master-metered building have different rules?

Yes. Shifting heating costs to rent-stabilized or rent-controlled residents is explicitly prohibited under HPD’s Electric Heating Policy with no exception pathway. Resident-paid cooling through a compliant EAS and PSC-authorized submetering arrangement is permitted, but the board must be careful that billing covers only confirmed cooling consumption and that any shoulder-season ambiguity is absorbed by the owner rather than passed to stabilized tenants.