A residential solar contract in New York City is signed in an afternoon. The system is energized somewhere between two months and a year later.

Everything in that gap is invisible to the customer, mostly invisible to the salesperson, and almost entirely responsible for whether a solar business makes money. The panels are a commodity. The inverter is a commodity. What is not a commodity is the ability to move one project through six independent approval processes, each run by a different authority, each with its own definition of complete, several of which must happen in an order that is not obvious from outside.

What follows is that gap as a clock. The timeline is composite, drawn from multiple engagements rather than any single project, but every gate and every ordering rule in it is real.

Day 0: the contract is signed

Three things can start this afternoon and have no dependencies on anything else.

The structural review. A Professional Engineer or Registered Architect has to certify that the roof carries the array -- dead load, wind uplift, snow -- and that the attachment method is sound. In New York this is not a formality. The building stock is old, roof assemblies are frequently undocumented, and what is on the drawings is often not what is on the roof.

The ACP-5. If the building went up before April 1, 1987, a rooftop alteration permit requires asbestos certification from the Department of Environmental Protection. The instrument is an Asbestos Assessment Report signed by a Certified Asbestos Investigator, and it is a negative certification: nobody abates anything, an investigator attests that the scope will not disturb asbestos-containing material. Roof penetrations for racking disturb existing roofing, which is why solar work triggers it so reliably. It is cheap, routine, and one of the most common causes of schedule slip in the entire process, purely because nobody started it.

The electrical filing. Held for a moment, because it is the trap.

None of the three costs anything to begin on day one. Every week they sit is a week added to the far end, and it is added invisibly, because nobody experiences a delay at the beginning.

Week 1: the fire code decides how big the system is

New York City Fire Code § 504.4 governs rooftop access, and it is what most often shrinks a system between the sales proposal and the permit set.

The requirement is a clear six-foot path across the roof, preserved access to bulkheads, fire escapes, and vents, and a six-by-six clearance at rooftop access points. On a wide Brooklyn rowhouse roof that costs a couple of panels. On a narrow or heavily obstructed roof it can remove a third of the proposed array, and the payback math the customer agreed to goes with it.

Where compliance is genuinely ambiguous the Fire Department will consider a variance under § 104.8. That is a separate filing with its own fee and its own weeks, and it must land before the Department of Buildings filing rather than alongside it.

The commercial point matters more than the technical one. Design to the fire code before you quote, not after you file. Every panel removed post-contract is a conversation about why the number changed, and those conversations lose deals that were already won.

For landmarked buildings and properties in historic districts, Landmarks Preservation Commission approval is a separate and earlier gate, and it governs what the array is permitted to look like from the street.

Week 3: the ordering trap

Filings go through DOB NOW, mandatory for solar since November 2023. Two of them are required, and they are not the same filing.

A solar job filing, an Alteration with work type Solar. And a separate electrical filing, submitted by a licensed electrician, under category of work Sustainable Energy Installs, sustainable type Photo Voltaic.

Here is the thing that is stated plainly in DOB’s own guidance and missed constantly:

The solar permit will not be issued until the electrical permit has been issued.

Treat the electrical filing as a downstream task, something the electrician picks up closer to install, and you have blocked your own solar permit. Two to three weeks, gone, for no reason, discovered late.

Nobody in that chain did anything wrong. The electrician was working to a normal understanding of when electricians get involved. That is what a sequencing failure looks like from the inside: everyone competent, everyone on schedule against their own task, and the project stalled.

One more change worth knowing, because most quoted timelines have not absorbed it. Solar filings can no longer be professionally certified, and neither can objections raised against them. Professional certification is the mechanism that lets a licensed professional self-certify code compliance and skip plan examination. Without it, every solar job goes through examination, and every objection is resolved through examination. That is a permanent addition to the schedule.

Week 6: the utility’s clock starts, and its speed depends on one number

An array that cannot export to the grid is an expensive roof ornament. Permission to Operate comes from Con Edison under New York State’s Standardized Interconnection Requirements, the statewide process administered by the Department of Public Service covering distributed generation of 5 MW or less. Smart inverters have been mandatory statewide since January 2023.

There are effectively two different processes and one number decides which one you are in.

At or below 50 kW-AC, the typical residential and small-commercial case, the path is comparatively clean. Application through PowerClerk, utility review of the one-line diagram in roughly ten business days, an approval letter, construction, inverter testing, self-certification back through the portal, then final review, net meter, acceptance. No application fee. No system impact study.

Above 50 kW it changes character entirely. An optional pre-application report, a $750 application fee, a completeness review, a preliminary screening analysis, and if the project fails screening, a CESIR -- the in-depth study determining what distribution upgrades the project triggers and what they cost. Cost commitments above $10,000 carry their own payment milestones. A CESIR can return a number that ends the project.

That threshold is one of the most consequential design decisions in any commercial job, and it is routinely made by someone sizing an array who does not know the threshold exists.

Somewhere in here: the money, which has its own deadlines

Two programs carry most of the economics and both are procedural rather than technical.

NYSERDA NY-Sun runs on a Megawatt Block structure, a declining per-watt incentive that steps down as capacity in each block and region is claimed. Con Edison territory is its own region with its own block. The incentive is claimed by a NYSERDA-approved participating contractor through the program portal, not by the customer, and reaches the customer as a reduction in contract price. Because blocks close as they fill, the rate you get is a function of when you submit. That makes incentive capture an operational discipline, not a sales talking point.

The NYC solar property tax abatement under Administrative Code § 499-aaaa is worth 30% of eligible installed cost, capped at $250,000, taken at 7.5% per year across four years, beginning July 1 following DOB approval. It now covers battery storage as well as PV. Available to tax classes 1, 2, and 4, but not to properties receiving ICAP, 421-a, 421-b, or 421-g, not to properties paying PILOTs, and not to fully tax-exempt properties.

Two procedural facts do real damage when missed. There is no longer a separate paper application: the request is made inside the DOB NOW solar job filing, and a filing already submitted without the checkbox is tedious to unwind. And the annual deadline is March 15 for the abatement to take effect that year. A project closing out on March 20 waits twelve months for money the customer was told to expect.

Month 4, if it went well

Two to four months from signature to permission to operate is a reasonable plan for a straightforward residential or small rooftop system. Anything commercial, anything above 50 kW, anything landmarked, or anything with a complicated roof runs substantially longer, and the customer’s expectations should be built around the long case rather than the brochure case.

Look back at what actually consumed the schedule.

Not difficulty. Every requirement above is knowable, published, and routine. What consumed it was ordering: an electrical filing that had to precede a solar permit, an ACP-5 that could have started on day one and started in week six, a fire code path that should have shaped the design and instead invalidated it, an abatement checkbox living inside a filing already submitted, a CESIR nobody knew a 60 kW array would trigger.

And underneath the ordering, ownership. Each gate belongs to a different party: the engineer, the electrician, the asbestos investigator, the expediter, the utility, the customer’s accountant. Every one of them is doing their own job competently. Nobody owns the space between them.

Every delay I have watched in this business happened in that space.

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Trevor MacDermid is principal consultant at Ten Mississippi, working on solar deployment and building energy compliance in New York City. NABCEP PV Technical Sales Professional.

This paper describes process as of August 2026 and is composite expertise drawn from multiple engagements, not a description of any single project. Requirements change; verify current rules with DOB, DEP, Con Edison, and NYSERDA before relying on any of it. Nothing here is legal, engineering, or tax advice.