Local Law 87 is the quieter cousin of LL84 and LL97. It does not generate a public score, it does not assess penalties on emissions, and most owners only think about it once every ten years. That timing is the problem — when the deadline arrives, owners are unprepared, the engineering market is squeezed, and the filing is rushed. This piece covers what LL87 actually requires, how the audit and retro-commissioning differ, and how to budget for it.
The basic structure
LL87 applies to buildings over 50,000 square feet. Every ten years, the owner must complete and file two things:
- An Energy Efficiency Report (EER) — an ASHRAE Level II energy audit.
- A Retro-Commissioning (RCx) Report — a tune-up of base building systems.
The ten-year cycle is not aligned to the calendar — it is aligned to the building's tax block, the same way FISP is. The DOB publishes an annual list of which blocks have filings due in the calendar year. Owners need to check the list every year, because a missed deadline is a $3,000 violation per year of non-compliance, plus the cost of an expedited rush job to get current.
If you are within 18 months of your filing deadline and you have not engaged an engineer, you are already late. The good firms book a year out, and the bad ones produce reports DOB rejects.
What the energy audit actually covers
The EER is an ASHRAE Level II audit. That is a specific ASHRAE designation with required scope:
- A site visit by a qualified energy professional — typically a PE with a CEM or CEA credential.
- Examination of every base building system: heating, cooling, ventilation, domestic hot water, lighting, controls, motors, vertical transportation.
- Energy use breakdown by end use, validated against utility bills.
- Identification of energy conservation measures (ECMs), each priced and analyzed for simple payback.
- A summary table sorted by payback that the building can use as a capital plan.
The audit doesn't fix anything. It is diagnosis. The output is a thick report, a filing summary signed by the auditor, and a DOB EER form submitted through DOB NOW.
A useful audit produces 15 to 25 specific ECMs spanning short payback (controls tuning, lamp swaps, sensor installations) to capital-intensive (boiler replacement, envelope work). A useless audit produces three generic recommendations and a thousand pages of equipment lists. Read the audit before paying the final invoice.
What retro-commissioning covers
RCx is the action half. It is a structured tune-up of existing base building systems to make them perform the way they were designed.
The required RCx scope under LL87 includes:
- HVAC operation testing. Are the boilers cycling correctly? Are pumps running when they should be? Are the dampers actually moving?
- Control system review. BAS schedules, setpoints, sequence of operations. The audit team verifies what the system is actually doing — not what someone says it does.
- Envelope inspection. Doors, windows, vestibules, exhaust openings. Drafts and air leakage.
- Domestic hot water. Tank temperatures, recirculation pumps, mixing valves.
- Lighting and plug loads. Hours of operation, control strategies, occupancy sensing.
The team produces a list of corrections — items that need to be fixed for the systems to function as designed. Some are immediate (a stuck damper, a failed sensor); some are operational (incorrect setpoint, schedule never reset after the pandemic). The owner is required to implement the no-cost and low-cost items and document them in the RCx report.
A good RCx finds 10 to 30% energy savings through operational changes alone — no capital. That is the savings most owners leave on the table.
What does it cost
Pricing in 2026 for buildings of typical complexity:
- Small (50,000–100,000 sf, simple systems): EER $15,000 to $25,000. RCx $20,000 to $35,000.
- Mid (100,000–300,000 sf): EER $25,000 to $50,000. RCx $35,000 to $80,000.
- Large or complex (300,000+ sf, district steam, VAV, central plant): EER $50,000 and up. RCx $80,000 and up.
Often the same firm does both, and there is overlap in the data collection. Bundling can save 10 to 20%. But verify the team has both audit and commissioning credentials — they are different skill sets.
How LL87 ties into LL97
This is the part owners increasingly care about in 2026. The LL87 audit is a perfect feasibility tool for LL97 planning. A Level II audit done well will:
- Quantify your current emissions per fuel.
- Project emissions under each ECM.
- Highlight the electrification candidates and what infrastructure would be required.
- Surface envelope defects that drive heating loads.
If you have an LL87 deadline coming up and a Period 2 LL97 problem looming, ask the auditor to extend the scope to include LL97 modeling. The marginal cost is small and you avoid paying twice for the same site visit and equipment survey.
The biggest mistake we see: owners treat LL87 as a regulatory chore and put the report in a drawer. The audit is the cheapest decarbonization roadmap you will ever buy. Use it.
Common filing pitfalls
The "cover sheet only" filing. DOB requires the full audit and RCx reports be submitted, not just the summary forms. Some owners file the cover and assume that is enough. Audits frequently reject this.
Wrong building square footage. LL87, LL84, and LL97 should all use the same gross square footage. Inconsistencies trigger questions across all three filings.
ECMs without engineering basis. Recommendations based on vibes ("upgrade to high-efficiency boilers") rather than load calculations. Reviewers spot this immediately.
No follow-through on no-cost RCx items. The RCx report is supposed to document that the operational corrections were actually made. If the report says "fix the BAS schedule" and the BAS schedule was never fixed, the filing is technically deficient.
A 24-month workflow
If your filing window opens in 2027:
- 24 months out: Engage firm. Lock dates.
- 18 months out: Audit fieldwork. Multiple site visits.
- 12 months out: Draft EER. Identify ECMs.
- 9 months out: RCx fieldwork begins.
- 6 months out: RCx implementation phase. Fix the no-cost items.
- 3 months out: Final reports. Review.
- Filing window: Submit through DOB NOW. Save confirmations.
For portfolio owners, the audit and RCx cycles for different buildings rarely line up. Tracking each one independently is exactly the kind of thing LLDesk keeps on top of automatically.
Key takeaways
- LL87 applies to buildings over 50,000 sf. Every ten years on a tax-block schedule, the owner files an ASHRAE Level II audit and a retro-commissioning report.
- The audit identifies energy conservation measures with paybacks. The RCx tunes existing systems and documents low-cost corrections.
- A good LL87 cycle is the cheapest decarbonization roadmap available — use it for LL97 planning.
- Late filings cost $3,000 per year. Engage your engineer 18 to 24 months out.
- Don't file the cover sheet only. The full audit and RCx reports must be submitted.