Verified locally
Permits and roofing rules in Commerce
Most roofing advice on the internet is written for nowhere in particular. This page is the opposite: only the things we could confirm about Commerce specifically, each one traceable to the authority that published it.
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- Deleted after 90 days. If nobody can take it on, or you do not say yes, your contact details are deleted 90 days after your request.
- You decide, or you do not. There is nothing to cancel and nothing to pay us.
Nobody will call you about this request unless you say yes to a company by name.
Anything we could not read on an official source is absent from this page. That is deliberate: a wrong permit fee is worse to a homeowner than no permit fee.
The climate zone your roof is built to
Commerce is in IECC climate zone 3 and a dry one (the Building America map calls it Hot-Dry), on the Department of Energy county map. That single number is what the energy code is written against here, and it is the reason the same roof is specified differently two states away.
Zone 3 is warm enough that no ice-barrier is required at the eaves, so a quote carrying one is selling you something the code here does not ask for. That is not automatically wrong, but it should be a line you agreed to rather than one you discover.
Attic ventilation is the figure worth checking either way: the energy code works to 1 square foot of net free vent area per 150 square feet of attic floor, or 1 per 300 where the venting is balanced between intake low and exhaust high. Most roofs that fail early in any zone fail because the intake was blocked, not because the covering was cheap.
The statewide layer
State-level requirements sit underneath everything above. They are included because more than one of them is commonly misstated, and because a homeowner who knows them can tell a careful quote from a careless one.
The right to cancel
A home improvement contract can normally be cancelled within three business days, and within five if the buyer is a senior citizen. Where the contract is to repair or restore residential damage from a disaster or a declared state of emergency, that window is seven business days.
That longer window exists because of what happens on a street after a storm. Nothing has to be signed at the door — and if something was, the clock above is why it is worth re-reading tonight rather than tomorrow.
What a wildfire-zone roof actually has to include
In a mapped fire hazard zone the requirements reach well past the covering, and they are the details that separate a compliant roof from a cheap one. Embers, not flame fronts, are what destroy most houses in a wildfire, and every one of these requirements is about closing a gap an ember could get through.
- A roof assembly meeting Class A when tested to ASTM E108 or UL 790
- On profiled tile, bird stops at the eaves and hip and ridge caps mudded in, so there is no open end for embers to enter
- Valley flashing of at least 0.019 inch (26 gauge) corrosion-resistant metal, over a mineral-surfaced cap sheet at least 36 inches wide
- Noncombustible gutters and downspouts, with an approved means of stopping leaves and debris collecting in them
- Vent screening of noncombustible corrosion-resistant mesh, no finer than 1/16 inch and no coarser than 1/8 inch
Fire classification: what is actually required, and where
The statewide floor is a Class C fire-retardant roof covering. That applies to a new roof, to any repair or replacement, and to any existing building where more than half the roof area is replaced within a year — which is every ordinary re-roof.
The highest classification, Class A, is pulled in by fire hazard severity zoning or wildland-urban interface designation, and by local ordinances that reach further. Over most of south Orange County the answer ends up being Class A — but it gets there through the zoning and the city, not through a blanket state rule, so it is a question to settle for your address.
As of 1 January 2026 the wildfire rules live in their own book: the California Wildland-Urban Interface Code, Title 24 Part 7, which consolidated what used to be Chapter 7A of the building code and section R337 of the residential code. A contractor still citing Chapter 7A is citing something that has been superseded.
The code your roof will be built to
The rules a California re-roof is built to live in Title 24, the state building standards code. Its 2025 edition governs any project whose permit application went in on or after 1 January 2026. A roof installed before that date was built to an older edition, and not everything acceptable then is acceptable now.
This is practical rather than academic. A contractor quoting from memory instead of from the edition currently in force will occasionally price a detail that will not pass — and the inspection comes at the end of the job, not the beginning.
How many layers can stay on
A new covering may not be laid over the old one where there are already two applications of any type on the roof, where the existing roof or covering is water-soaked or has deteriorated enough that it is no longer a sound base, or where the existing covering is slate, clay, cement or asbestos-cement tile. In those cases the roof comes off to the deck.
Two layers is therefore the practical ceiling, and on an older house nobody knows how many are up there until somebody looks. That is the single most common reason a re-roof price changes after the work starts, and it is a fair reason to ask for the quote to state what happens if a third layer appears.
Housing stock, access and exposure
Everything above this heading was read on an official source. Everything below it is inference from the housing stock and the geography — useful, and a different kind of statement. It is separated out so you can tell which is which.
We have not compiled a verified housing-era note for Commerce, so nothing is claimed here about the typical age or material of its roofs.
Salt exposure changes what a good specification looks like on this coast. The covering is rarely the problem; the ferrous parts holding it down are. A quote that names the fastener and flashing material is a quote from someone who works here.
Tear-off is the other thing that separates a real local quote from a calculator. A re-roof produces several tons of waste, it has to go somewhere, and where a truck can park relative to the roof changes both the labour and the disposal cost. On tight lots, hillside driveways and streets where a skip needs a permit of its own, that is not a rounding error.
Check it
Rules change, fee schedules are revised annually, and your particular roof may raise something none of this covers. Confirm anything that matters with your city’s building department before work starts — and a contractor who works here every week will already know most of it.
Checkable sources
Listed so the claims on this page can be checked rather than taken on trust.
- California Building Standards Commission — 2025 Title 24, effective 1 January 2026
- California Energy Commission — 2025 Building Energy Efficiency Standards
- CAL FIRE / Office of the State Fire Marshal — Fire Hazard Severity Zone viewer
- CSLB — C-39 roofing classification
- Business & Professions Code 7159.5 — down payment limit
- Business & Professions Code 7030.5 — licence number in advertising
- Insurance Code 2051.5 — time to collect replacement cost
- 10 CCR 2695.7 — Fair Claims Settlement Practices Regulations
- CalRecycle — CALGreen construction and demolition diversion
Permit questions
Who pulls the permit, me or the contractor?
The contractor, normally, and it should be in the written quote that they will. An owner-builder permit exists in most places but it moves the liability for the work onto you, which is rarely what a homeowner actually wants.
What is the inspection for?
To confirm that what went on the roof matches what the code requires, at the stage when it can still be seen. A contractor who treats the inspection as an obstacle is telling you something.
Does a re-roof need a permit?
In practice, yes, almost everywhere and certainly for a full replacement — and the permit is normally pulled by the contractor, not by you. A job done without one can cause real trouble at sale, because it shows up as unpermitted work on a house nobody can now inspect. Ask to see the permit number.
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