Wiring a renovation for bidirectional EV charging

No universal V2H charger exists

Each automaker that supports vehicle-to-home power specifies its own equipment. The main US options as of October 2026:

Choosing the vehicle therefore fixes the V2H equipment. A GM truck cannot use a Tesla Gateway, and a Kia cannot use a GM kit (opens an external site). Buying a bidirectional charger before the vehicle is a bet we advise against.

Certifications that matter

• UL 9741 (opens an external site): the safety standard for bidirectional EV power export equipment located outside the vehicle, up to 1,000 volts AC and 1,500 volts DC. Listed products appear under UL product category FFTN (opens an external site).
• UL 1741 SB: the grid-support certification, used with IEEE 1547-2018, that utilities rely on when they review equipment for interconnection.
• UL 1741 Supplement SC with SAE J3072: the path for AC bidirectional charging, in which the vehicle's onboard inverter exports power and the charger authorizes it. SAE J3072 was finalized in 2024, Supplement SC was issued in May 2026 and UL Solutions opened certification testing in September 2026. It is the likely route to lower-cost V2G.
• NEC 625.48: charging equipment that exports power in an interactive system must be listed and marked as suitable for that purpose. The NYC Electrical Code, based on the 2020 NEC, contains the section; the electrician confirms any local amendments.
• ISO 15118-20: the communication standard for DC bidirectional charging. Federal NEVI rules (opens an external site) (23 CFR 680.108) require federally funded public chargers to have hardware capable of ISO 15118-2 and ISO 15118-20. No such rule applies to home chargers.

Choosing the charger now

Vehicle first, charger second. If backup power matters, choose a vehicle whose automaker sells V2H in New York today and confirm the build date and state eligibility.

If you do not need V2H yet, buy an affordable, hardwired, UL-listed Level 2 charger that is ENERGY STAR certified or on the EPRI Vetted Product List, which PSEG Long Island requires for its rebate. Choose a J3400 cable or a replaceable cable, and treat the unit as replaceable. Prefer chargers that support OCPP and connect by Wi-Fi or Ethernet, so that utility managed-charging programs can work with them. Do not pay extra for a charger marketed as V2G-ready unless it carries a UL 9741 or UL 1741 SC listing and approval from your vehicle's maker; without both there is no assurance it will ever export power from your car.

What to rough in while the walls are open

• Conduit from the panel or service area to the parking space, sized for a future 100-amp circuit (an 80-amp charger) even if the first charger is 40 to 60 amps, with a pull string. The licensed electrician selects the size from conductor type, fill and run length.
• Panel space: two reserved spaces for the EV circuit, and a planned location between the meter and the main panel for a transfer or interconnection device (a gateway, transfer switch or backup interface). Keep wall space near the meter clear.
• A backup-loads subpanel grouping the refrigerator, heating controls, sump pump, network equipment and lighting, so that a future V2H system, generator or battery can supply it. A V2H source of 9.6 to 11.5 kW cannot run an entire house with central air or electric heat running.
• Cat6 cabling to the charger location and to the future gateway location.
• Solar coordination: the NEC 705.12 busbar rule (the 120 percent rule) limits how much generation the panel can accept, so EV, backup and solar plans are designed together.
• A charger location in the garage with shade, ventilation and the manufacturer's required clearances. Kia, for example, requires a garage or carport with shade and ventilation for its V2H equipment (opens an external site).
• Electrical permits and inspections. Conduit, panel and subpanel work is permitted electrical work, filed by the licensed electrician as part of the renovation.

When a renovation already opens walls and ceilings, the rough-in costs a fraction of what it costs to open finished surfaces later. We write the conduit, panel planning, backup subpanel and low-voltage cabling into the renovation scope, coordinate them with any solar plans and install the charger once the vehicle is chosen. For the bidirectional equipment, we plan and install the electrical side and coordinate the manufacturer-certified installation where the system requires one. The electrical work is performed by licensed partner electricians.

In co-ops and condominiums, bidirectional charging is rarely practical without a dedicated service. For those buildings, the make-ready and Charge Ready NY programs described in our guide to 2026 EV charging incentives are the better starting point.

Approval paths, J3400 and ISO 15118-20

A system that disconnects the house from the grid before the vehicle supplies power is treated differently from one that exports while connected. Exporting systems go through the utility's interconnection review under the New York State Standardized Interconnection Requirements (SIR), which rely on IEEE 1547 and UL 1741 SB certified equipment. As of October 2026, how New York utilities will review backup-only bidirectional chargers is still under discussion in a state working group. We design for isolated backup first, which keeps approval simpler and leaves room for export later.

The vehicle inlet is changing from CCS1 to J3400 (opens an external site) across North America. The wiring is unaffected: the same circuit and conduit serve either connector, and a charger with a replaceable cable can follow the change. Communication protocols are a different matter. A charger can be upgraded to ISO 15118-20 by firmware only if it already has the necessary communication and security hardware, so ask the manufacturer for a written statement of ISO 15118-20 hardware capability. No one can promise that a vehicle or charger sold today will support V2G later. The wiring is the part of the decision that does not expire.