Key takeaways
- From October 26, 2026, the Registration Numbers, Installation Dates and Commission Dates for cooling towers must be added to all Mechanical (MS) filings that require a Certificate of Compliance.
- The registration number is not new. It comes from the Local Law 77 of 2015 registration every tower already has to carry before it first runs.
- The change bites at sign-off, not at filing. A Certificate of Compliance is the end of the job, which is the worst moment to discover a missing number.
- Towers must be registered before initial operation, certified annually under §28-317.5, and reported within 30 days when removed under §28-317.3.1. Failing any of these is punishable by a fine of up to $10,000.
In this article
This is the kind of change that reads like housekeeping and costs a week. The Department has added three fields to Mechanical filings, and they are fields most contractors do not have at hand on the day they need them.
What changed
The Department issued the notice on October 21, 2026, effective October 26: Cooling Tower System Registration Enhancement in DOB NOW. Its wording is short. Beginning October 26, 2026, the Registration Numbers, Installation Dates and Commission Dates for cooling towers should be added to all Mechanical (MS) filings that require a Certificate of Compliance.
Three fields, per tower. Nothing about the work itself changes; what changes is what the filing has to carry before it can be closed out.
Which filings this touches
Mechanical work filed as an MS job where the scope ends in a Certificate of Compliance. In practice that is the HVAC side of most alterations and new buildings that involve a cooling tower, a fluid cooler or an evaporative condenser.
If the mechanical scope has no such device, there is nothing to enter. If it has one — including one that was already on the roof before the job started and stays there — the numbers belong on the filing.
Where the numbers come from
None of this data is created by the filing. It already exists, because every cooling tower in New York has had to be registered since Local Law 77 of 2015.
| Field | Where it comes from |
|---|---|
| Registration Number | The Department's cooling tower registration portal, assigned when the device was enrolled |
| Installation Date | The date the device was physically installed |
| Commission Date | The date it was first put into operation |
The registration itself is the owner's duty, not the filing applicant's: a tower must be registered prior to initial operation, and towers that existed when the law took effect on August 18, 2015 had thirty days to register. On a building where the owner has kept that record properly, the number is a lookup. On a building where nobody has thought about the roof in ten years, it is a hunt.
Why this lands at the worst moment
A Certificate of Compliance is not a mid-job document. It is how mechanical work is signed off. An applicant who reaches that point and finds the tower was never registered, or was registered under a defunct managing agent, is not filling in a blank — they are starting a registration, and the work waits.
This is the same shape as the other DOB NOW changes of the past year: nothing about the construction is different, but a document that used to be somebody else's problem now sits on the critical path. We wrote about the same pattern when licensing and agency registration moved into DOB NOW.
What to do before you file
- Ask the owner for the registration number at the start of the mechanical scope, not at sign-off. One email, ten weeks early, costs nothing.
- Check the registration is live and in the right name. A tower registered by a managing agent who no longer holds the building is a record nobody can update quickly.
- Pin down the two dates. Installation and commission are different dates and the filing asks for both. On an existing tower they come from the owner's records; on a new one, from your own.
- For a new tower, register before it runs. The law is explicit: registration comes before initial operation, not after.
- If a tower is coming out, say so within thirty days of removal, with the statement that it was drained and sanitized.
The annual certification is a separate obligation and it does not go away because a filing is open. Owners certify each year that the tower was inspected, tested, cleaned and disinfected, under §28-317.5. Buildings on the 2026 covered buildings list for Local Law 97 tend to be exactly the buildings with towers on the roof, so the two calendars usually belong to the same person.
Frequently asked questions
Does this apply to a tower that was already there before our job?
Yes. The requirement attaches to the Mechanical filing, not to the device being new. If the filing requires a Certificate of Compliance and there is a tower, the numbers belong on it.
What if the tower was never registered?
Then it has been out of compliance since before your job, and the registration has to be made. Registration is required before initial operation, and failing to register is punishable by a fine of up to $10,000.
Who is responsible for registering, the owner or the contractor?
The duty sits with the owner or property manager. The filing applicant is the one who discovers the gap, which is why asking early matters.
Is the installation date the same as the commission date?
Not usually. Installation is when the device was put in place; commission is when it was first operated. The filing asks for both.
Does any of this change the inspections on the job?
No. Special and progress inspections on the mechanical scope are unchanged. This is a filing data requirement, not a technical one.
Conclusion
Three fields, no new work, and a deadline that already passed on October 26. The only thing worth doing is moving the question forward in the schedule: find the registration number when the mechanical scope starts, not when the Certificate of Compliance is the last thing between you and closeout.
Written by the engineers and laboratory technicians of Metric Consulting and Inspection, a Class 1 special inspection agency with a DOB-licensed concrete testing laboratory in Hicksville, New York, serving NYC construction since 2003.