LL87 vs LL88 vs LL84 vs LL97: Which NYC Energy Local Law Hits You First?

If you own a NYC building over 25,000 sq ft, you're subject to four overlapping energy local laws — LL84, LL87, LL88, and LL97 — that together create the most expensive ongoing compliance regime in the city. Owners new to the space frequently confuse them. Owners who think they've handled "the energy law" usually mean LL84 (benchmarking) and miss LL97 (the one with seven-figure penalty exposure).

This guide compares the four laws side by side, explains how they interact, and walks through which one fires first against any given building — with a decision tree at the end. If you have time for only one regulatory comparison this year, this is the most operationally useful one.

01 · THE FOUR LAWS AT A GLANCESide-by-side comparison

02 · LL84Benchmarking — the data foundation

LL84 is the simplest of the four. It requires owners to enter their building's annual energy and water consumption into ENERGY STAR Portfolio Manager, then file a confirmation with DOB by May 1 each year. The data feeds LL95/33 (energy grade) and LL97 (emissions calculation) directly.

What it actually requires

• ENERGY STAR Portfolio Manager account configured for the building
• Annual electricity, gas, steam, fuel oil, and water consumption entered
• Building characteristics (occupancy, gross floor area, year built) confirmed
• Filing through DOB NOW

Why it matters

If your LL84 data is wrong or missing, your LL97 calculation is wrong. Mismatches between LL84 and LL97 trigger LL97 filing rejections, and rejected filings convert to failure-to-file penalties at $0.50/sq ft. Get LL84 right.

03 · LL87Energy audit + retro-commissioning

LL87 requires a full energy audit and retro-commissioning of the building's energy systems every 10 years. The deliverable — the Energy Efficiency Report (EER) — identifies retrofit opportunities and confirms operational tuning is up to date.

What it requires

• Energy audit — performed by a Certified Energy Auditor (CEA, BPI MFBA, or similar credential). Documents existing energy performance, identifies cost-effective retrofits, projects savings.
• Retro-commissioning — performed by a Certified RCx Agent. Tunes existing systems (HVAC, lighting controls, BMS) to operate at design efficiency.
• EER filing — combined deliverable due Dec 31 of the building's cycle year, filed via DOB NOW.

Why it matters

The audit recommendations are the foundation for your LL97 decarbonization roadmap. Skipping LL87 means flying blind into Period 2 LL97 caps. Owners who run a serious LL87 process typically save more on LL97 retrofits than the audit costs.

04 · LL88Lighting + sub-metering — mostly complete

LL88 was a one-time obligation with a Jan 1, 2025 deadline. Buildings over 25,000 sq ft with tenant spaces over 10,000 sq ft were required to upgrade lighting to current code and install sub-meters at tenant spaces.

Status in 2026

• Compliant buildings — most NYC buildings completed by 2025 deadline. Ongoing maintenance is the only obligation.
• Partial buildings — lighting done, sub-metering missing. Still exposed to LL88 penalty until cert filed.
• Non-compliant — no cert on file. $1,500/year penalty + DOB violation on record.

Why it still matters in 2026

Buildings still non-compliant can resolve quickly — install the missing sub-meters or file the missing certificate. The penalty is small per year but ongoing, and any DOB activity on the building (new permits, BIS profile reviews) surfaces the LL88 violation.

05 · LL97The carbon law — the largest exposure

LL97 is the largest financial regulation on this list, by a wide margin. It sets declining caps on building carbon emissions and assesses penalties at $268 per metric ton CO₂e over the cap.

What it requires

• Annual BEEC report due May 1, signed by Registered Design Professional
• Emissions under the cap — calculated as occupancy coefficient × gross floor area
• If over cap: $268 × tCO₂e over limit, annually
• Period 1 (2024–2029) caps are mild; Period 2 (2030–2034) caps drop 40–70%

Where the exposure comes from

For a 100,000 sq ft Class B office building running 10% over its Period 1 cap: roughly $25,000–$45,000 per year. For a 500,000 sq ft hotel: potentially $200,000+/year. For Class I-2 (hospital), the math gets dramatic — coefficients are higher because hospitals run intensive HVAC.

Deep dive: LL97 penalty calculator and decarbonization paths.

06 · HOW THEY INTERACTThe data flow between laws

The four laws are not independent — they form a chain. Get one wrong and the downstream laws fail.

07 · WHICH FIRES FIRSTThe decision tree

For any given building, the question is: "Which energy law is going to send me the first violation if I'm sloppy?" The answer depends on building size, age, and current compliance state.

If you've never filed LL84

LL84 fires first. The May 1 deadline is annual; missing it triggers $500–$2,000 penalty. More importantly, you can't file LL97 without LL84 data, so missing LL84 also gives you the $0.50/sq ft LL97 failure-to-file penalty. Two violations from one missed deadline.

If your building is over 50,000 sq ft and on LL87 cycle this year

LL87 fires next, by Dec 31. The procurement of energy auditor + RCx agent takes 6–9 months; if you haven't started by Q2, you're at risk.

If your building is exceeding LL97 Period 1 caps

LL97 fires every May 1, every year, with the largest dollar exposure. The exceedance penalty applies even if you filed on time — you just owe the calculated amount.

If LL88 was missed in 2025

Ongoing $1,500/year. Not the biggest fish, but accumulating.

08 · COST PER LAWWhat compliance actually costs

For a typical 100,000 sq ft mid-size NYC building:

09 · THE PORTFOLIO ANGLEVolume economics

For owners with multiple covered buildings, the four laws benefit from being run as a single workflow:

• One ENERGY STAR Portfolio Manager account for all buildings — feeds LL84 + LL97 + LL95/33 simultaneously
• One RDP retainer covers LL97 BEEC sign-offs across the portfolio
• One LL87 procurement staggered across buildings on different cycles
• Centralized LL97 modeling — Period 2 retrofits planned at portfolio level

Per-building costs drop 30–50% at portfolio scale relative to ad-hoc engagement.

10 · MONITORINGTracking four laws across a portfolio

Manual tracking of four energy laws across a 10-building portfolio gets unmanageable fast. Each building has its own LL87 cycle position, its own LL97 cap math, and its own filing history. Discrepancies between LL84 and LL97 inputs are invisible until DOB rejects the filing.

ViolationWatch tracks LL84 + LL97 + LL87 + LL88 deadlines per building automatically, surfaces DOB filing rejections within minutes, and flags any building approaching LL87 cycle ahead of the standard 9-month procurement window. Run a free check on any address or start a 7-day trial.

11 · BOTTOM LINEThe energy law cluster in one paragraph

LL84 is the data foundation, LL87 is the planning input, LL88 is mostly historical, and LL97 is where the real money lives. For any building over 25,000 sq ft: LL84 + LL97 every May 1, LL87 every 10 years (Dec 31 of cycle year), LL88 done if you're already compliant. Get LL84 right or LL97 fails. Run LL87 seriously or you're guessing at LL97 retrofits. Track Period 2 LL97 caps starting in 2030 — that's where most NYC owners face their hardest capex decisions of the decade.

For the broader sustainability picture, see our NYC sustainability local laws guide. For the master 2026 cluster, start at our 2026 NYC local laws guide.