Local Law 87 of 2009 — Energy Audit & Retro-commissioning

What Local Law 87 actually requires

LL87 is the deepest dive any NYC building law makes into how a property actually operates. Where LL84 just measures consumption and LL88 mandates specific physical upgrades, LL87 requires a comprehensive energy audit anda retro-commissioning study of the building's base systems — together compiled into a single Energy Efficiency Report (EER) filed with DOB once every ten years.

The two components are independent and serve different purposes:

The energy audit

A detailed assessment of all major energy-consuming systems — HVAC, lighting, building envelope, domestic hot water, controls. The auditor identifies energy conservation measures (ECMs) the building could implement, with cost estimates, projected savings, and payback analysis.

The audit's findings are recommendations, not mandates. Owners are not required to implement any of the ECMs the audit identifies. The deliverable documents the opportunities; what the building does with them is the owner's call.

Retro-commissioning (RCx)

A hands-on inspection and tune-up of the building's base systems. LL87 specifies 25 RCx items — verifying that controls respond correctly, sensors read accurately, equipment sequences run as intended, valves and dampers operate properly, and so on.

RCx deficiencies must be corrected. Where the audit produces optional recommendations, RCx produces mandatory remediation items. The findings, plus the corrective work taken, get documented in the EER.

The audit and RCx don't have to be performed by the same firm, but both feed into the same filing. Both must be performed or supervised by a qualified professional under DOB's LL87 rules — typically a Registered Design Professional (Professional Engineer or Registered Architect) carrying recognized energy-audit or commissioning credentials such as CEM (Certified Energy Manager), CBCP (Certified Building Commissioning Professional), BPI MFBA (BPI Multi-Family Building Analyst), or equivalent qualifications.

Who's covered, and finding your filing year

LL87 covers a smaller set of buildings than LL84 or LL88: buildings over 50,000 gross square feet, or two-or-more buildings on the same tax lot or governed by the same condo board with combined area over 100,000 sqft. Properties under 50,000 sqft fall under LL84's annual benchmarking obligation but escape LL87's decennial audit.

Each covered building's filing year is determined by the last digit of its tax block number. The cycle repeats every ten years:

• Block ending in 0 → file by Dec 31 of years ending in 0 (next: 2030)
• Block ending in 1 → file by Dec 31 of years ending in 1 (next: 2031)
• Block ending in 2 → file by Dec 31 of years ending in 2 (next: 2032)
• ...and so on through 9

You can find your building's tax block number on its property tax bill or in the NYC Department of Finance's property records. The DOB sends reminders roughly three years before the deadline, but the responsibility to know your block number — and your filing year — sits with the owner.

Coverage exemptions and deferrals:

• Tax Class 1 buildings (one-, two-, and three-family homes) — exempt
• New buildings with a first Temporary Certificate of Occupancy less than 10 years old at time of filing — may not need to undergo the audit/RCx cycle
• ENERGY STAR-certified buildings (with certification in 2 of the 3 years before the EER deadline) — may qualify for energy audit exemption
• LEED-certified buildings — may qualify for retro-commissioning exemption under specific conditions
• Substantially rehabbed buildings — may apply for a 10-year deferral if base systems comply with NYCECC

The 4-year audit window

A timing rule that catches owners off-guard: the energy audit cannot be completed more than four years before the EER is filed. Start the audit too early and the results go stale; the work has to be redone before the EER can be submitted.

The practical implication is that owners who treat LL87 as a “we'll get to it next year” obligation lose flexibility. A building with a 2030 EER deadline can have its audit performed any time from 2026 onward, but not before. Buildings that completed energy audits in 2024 for other purposes can't necessarily reuse them for an LL87 filing five or six years later.

The 4-year window is one of the strongest arguments for synchronizing LL87 work with other compliance and capital planning — the audit work overlaps with what an owner would do anyway when planning a major retrofit, when assessing LL97 emissions reduction options, or when scoping LL88 lighting upgrades. A coordinated approach turns the audit cost into shared infrastructure rather than a standalone compliance expense.

Deadlines, extensions, and deferrals

The annual deadline is December 31of the building's assigned filing year. The 2026 cycle deadline was moved to March 31, 2026 as a one-time extension.

If a building can't meet its deadline, two paths exist:

Extension (1 year). Submit Form EER2 by October 1 of the due year, with the $155 extension fee. Extensions are not automatic — DOB evaluates each request individually based on documented circumstances. Renewable annually if needed, but each year requires a fresh request.

10-year deferral. Available for buildings that have undergone substantial rehabilitation within the prior 10 years and whose base systems comply with the NYC Energy Conservation Code. Submitted via Form EER1, also by December 31. Recently-renovated buildings often qualify and don't realize it — worth checking before defaulting into the audit cycle.

Penalty payments are submitted through DOB NOW: Safety as of January 6, 2025. Outstanding penalties may need to be resolved before a late EER can be fully accepted and closed, which means the penalty math has to be addressed alongside the corrective work — not in parallel with submission.

Penalties

LL87 has the most consequential penalty structure in the GGBP cluster — there is no annual cap.

Penalties keep accruing with no upper limit, and outstanding penalties may need to be resolved before a late EER can be fully accepted and closed. A building five years past its deadline owes $23,000 before it submits the report itself — on top of the audit and RCx work.

The math collapses an obvious choice for almost every covered building: doing the audit and filing on time costs less than two to three years of compounding fines. Buildings that have been ignoring an old deadline are usually better off curing the fines, doing the work, and filing — even years late — than continuing to ignore the obligation as the penalty meter runs.

Common pitfalls

Not knowing your tax block number.

This is the foundational pitfall. The filing year depends entirely on the last digit of your tax block number, and most owners don't know theirs offhand. Look it up on your property tax bill or in NYC DOF property records. Buildings with tax blocks ending in 6 are filing in 2026; blocks ending in 7 file in 2027. Calendar the deadline as soon as you know the year — the audit and RCx work takes 6–12 months done properly.

Completing the audit too early.

The audit cannot be older than 4 years at time of EER filing. Buildings that scoped audit work for other reasons (capital planning, energy bid solicitations, ConEd rebate qualification) can't necessarily reuse those audits for the LL87 EER years later. Time the audit to the EER, not to whatever else triggered the conversation.

Trying to file late while penalties remain outstanding.

Outstanding penalties may need to be resolved before a late EER can be fully accepted and closed. Owners who are years behind sometimes try to “catch up” by submitting the report and addressing penalties in parallel — this approach often runs into friction. Plan the cash flow to clear the penalty question before submission rather than alongside it.

Confusing audit recommendations with RCx deficiencies.

The audit produces recommendations. The owner is not required to implement them. RCx produces deficiency findings that mustbe corrected. Buildings that received an audit and saw the recommended ECM list often conclude (incorrectly) that LL87 doesn't actually require any work — missing the RCx component entirely.

Missing the ENERGY STAR or LEED deferral path.

Buildings with current ENERGY STAR certification (2 of 3 prior years) can qualify for energy audit exemption. LEED-certified buildings can qualify for RCx exemption. Both deferrals are available but not automatic — they have to be documented as part of the EER filing. Buildings that already maintain these certifications for other reasons routinely skip the deferral applications and pay for full audit/RCx cycles they didn't need.

If your block number is coming due

Buildings with tax blocks ending in 6 are in the 2026 cycle. Blocks ending in 7 are due in 2027. Blocks ending in 8 file in 2028, and so on.

The four-year audit window means a building due in 2027 can have its audit scoped any time from 2023 onward — but starting 24 months out is the realistic minimum to do the work properly: complete the audit and RCx in the field, surface and correct RCx deficiencies, and file before the December 31 deadline. Buildings starting later are usually choosing between rushed audit work, an extension request, or both.

If you're on a deadline year and haven't started — or you've started but the lighting, controls, or LL88 portion of the work hasn't been scoped — that's where coordinated field work pays off. The same survey that produces an LL88 attestation also produces audit-ready lighting documentation. One field engagement, two compliance deliverables, fewer trips into the building.

How LuxNet helps with LL87

LuxNet supports the field-survey and lighting-controls layer of the LL87 process. The EER itself is RDP-certified work and goes through firms with the specific credentials LL87 requires. Where LuxNet fits is the data layer the audit depends on: fixture-level lighting inventory, controls and sensor verification, occupancy-sensor function checks, tandem-wiring documentation, and the LL88 overlap.

For buildings approaching an LL87 cycle who also have an open LL88 obligation, the work compounds productively. The same lighting survey that produces the LL88 attestation deliverable feeds the LL87 audit's lighting-systems analysis directly. Owners who run these as a single coordinated engagement spend less in total than they would running them separately — and the audit gets better data to model from.

If your building has an upcoming LL87 deadline, a scoping call helps figure out the right structure: coordination with your existing EER auditor, a referral if you need one, or a survey deliverable that hands directly into the audit process.