Federal Courts Uphold Local Building Electrification Mandates in Maryland, New York, and Washington, Hardening LL97 and BERDO Compliance Liabilities

New York City property owners face a Good Faith Effort verification deadline on May 1 under Local Law 97, with retroactive penalties of $268 per ton of carbon dioxide for the 2024 and 2025 compliance years and $404 per ton beginning in 2027. The deadline arrives in a legal landscape that has shifted decisively in favor of the cities and states writing those rules.

Federal courts have upheld a string of local building electrification ordinances over the past year, reversing the chilling effect of the 9th Circuit’s 2023 ruling against Berkeley’s gas hook-up ban. Recent decisions in Maryland, New York, and Washington state have blessed building performance standards, gas hook-up restrictions, and net-zero codes, according to reporting by Canary Media. The cumulative effect is that the most aggressive municipal carbon mandates in the country now sit on hardened legal ground.

The Berkeley reversal in context. The 2023 9th Circuit decision struck down Berkeley’s restriction on natural gas piping in new construction, holding that the ordinance was preempted by the federal Energy Policy and Conservation Act. Industry groups read the ruling as a template for litigation against any local mandate that touched gas infrastructure. Building performance standards, which regulate emissions rather than appliances, were always a different legal animal, but the chill spread broadly across electrification policy.

The rulings of the past year have separated those categories. Courts in three states have now distinguished BPS regimes and emissions-based ordinances from direct appliance prohibitions, allowing the former to stand. The litigation risk that real estate trade groups had relied on as a pressure point against compliance investment has narrowed.

The compliance math at the building level. Local Law 97 covers buildings over 25,000 square feet in New York City, a portfolio that runs to roughly 50,000 properties. Phase 2 emissions limits, which take effect this year, tighten the cap on electricity, natural gas, and steam consumption per square foot. Owners who exceed the cap pay a penalty calibrated to the social cost of carbon, with the price escalating in 2027.

Compliance pathways are limited. Heat pumps and electrification of domestic hot water and heating systems remove on-site combustion and shift load to the grid. That shift raises peak demand and the demand charges that follow. Behind-the-meter storage absorbs the new peak, which is why the Urban Green Council and others have repeatedly identified storage as a Phase 2 lever.

Boston’s BERDO ordinance carries a similar structure, with mandatory emissions cuts on roughly 4,000 buildings and alternative compliance payments in the same per-ton range. Washington’s Clean Buildings Performance Standard and Maryland’s BEPS apply to commercial portfolios across both states. Each program now has an upheld federal precedent within its own circuit or an aligned circuit.

What hardened rules change for procurement. Real estate counsel had been advising owners that BPS deadlines might slip, that penalties might be litigated down, and that capital deployed against compliance was therefore optional. The court rulings remove the first two arguments. Penalties are due, and the structure stands.

That changes the discount rate inside a building owner’s compliance investment model. A capital project that pays back over seven years against a contingent penalty is a different decision from a capital project that pays back over seven years against a certain penalty. The latter is closer to a tax payment, and it competes for capital on different terms.

The implication for on-site storage is direct. A commercial battery in a New York or Boston building deferring peak demand reduces the electricity component of LL97 or BERDO emissions while also cutting demand charges that have escalated under Con Edison and Eversource rate cases. The two cash flows stack against the same capital outlay. Court hardening of the underlying mandate makes the penalty avoidance line item more bankable.

Eversource and the Massachusetts rate-design precedent. Massachusetts ran a winter rate program for heat-pump customers from November through March that delivered $37 million in savings to roughly 140,000 households, an average of $250 per customer, according to Canary Media. The structure isolates a load segment, prices it differently from the standard residential class, and reallocates costs without a cross-subsidy.

That same regulatory mechanic, separating a load class and pricing it on its own marginal cost, is the path that would eventually let utilities create a discount rate for commercial buildings with on-site dispatchable storage. Eversource’s experience designing and defending the heat-pump rate makes Massachusetts the most likely first jurisdiction to extend the template to a commercial demand-management class.

Federal supply alignment. LG Energy Solution confirmed in its Q1 2026 earnings release on April 30 that ESS cell manufacturing capex pushed the quarter to a loss but kept the company on track for a 50 gigawatt-hour annual US production target, with the GM-LG Ultium Cells Spring Hill conversion entering LFP production in Q2 2026 and feeding LGES Vertech for grid-scale, renewables-paired, and data-center applications. AESC, Samsung SDI, and SK Battery America are converging on US LFP production on parallel timelines.

The supply ramp matters for FEOC compliance under the OBBBA framework, which raises the Material Assistance Cost Ratio threshold for non-prohibited foreign content through the back half of the decade. Buildings procuring storage to comply with LL97 or BERDO can now plan against domestically sourced LFP cells without paying a Chinese-cell premium that has historically pushed commercial behind-the-meter pricing above utility-scale benchmarks.

Scope and limits. The rulings of the past year have not reopened gas appliance bans in the 9th Circuit. Berkeley remains preempted within that circuit’s reach. The legal hardening covers emissions-based and performance-based regimes, which are the dominant model in the largest commercial portfolios.

The May 1 LL97 verification deadline is one event in a longer cycle. The next compliance year tightens the cap further. Penalties are not theoretical, and the courts have now confirmed that the framework holding them is not, either.

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