How we work
Editorial & Research Standards
We publish a lot of technical material about California code, fire zones and building science. This page explains where those facts come from, how they are checked, and what happens when one of them stops being true.
Most contractor content is written once and never revisited. That is a real problem in California, where the wildfire building rules, the hazard maps and the defensible-space regulations have all moved within the last two years. Our answer is not to claim more expertise than we have. It is to be explicit about where every claim comes from, to date the ones that move, and to fix them in public when they change.
Where our facts come from
Sources are ranked, and a lower tier never overrides a higher one on the same question.
Tier 1
Primary, government and standards sources
Code text, statute and regulator publications. The California Building Standards Commission for code cycles and effective dates; the published Title 24 code text for requirements; leginfo for statutes; CAL FIRE and the Office of the State Fire Marshal for fire hazard designations; the Board of Forestry for defensible-space rulemaking; the Energy Commission for Title 24 Part 6; the CSLB for contractor and contract law; and individual county and city building departments for anything jurisdictional.
2025 California Wildland-Urban Interface Code §504.5 · Gov. Code §51179 · PRC §4291 · Placer County's own plan-check submittal sheet
Tier 2
Manufacturer primary documentation
Installation instructions, technical bulletins, published warranty text, product data sheets and evaluation reports. A manufacturer's claim is presented as a manufacturer's claim, attributed and dated. We do not promote marketing language into an independent scientific conclusion, and we do not quote a competitor's warranty or specification numbers second-hand.
James Hardie installation and HardieZone documentation · ICC-ES evaluation reports · LP Building Solutions technical literature
Tier 3
Independent research and building science
University programmes, research institutes, recognised building-science organisations and trade associations, used for mechanism and performance where no primary source covers the point.
Building Science Corporation · UC ANR Fire Network · IBHS · USDA Forest Products Laboratory · DOE and PNNL
Tier 4
Secondary sources — context only
Trade press and reputable general publications, used for context and for confirming that an event happened. A secondary source may establish that a board voted; it may never establish what a regulation requires. We do not cite content-farm articles as evidence for a technical claim, however well they rank.
Trade press · cost-versus-value survey data, attributed by edition
The rules we hold ourselves to
Regulatory claims are dated, and the date is on the page
Anything that can change — a code edition, a rulemaking status, a map adoption, a rebate — carries the date it was verified and, where the status is still moving, says so explicitly. We would rather publish "as of this date, awaiting publication" than a clean sentence that quietly becomes false.
We link the document, not the homepage
An external link exists to support a specific statement, and it points at the specific page or section that supports it. If a source cannot be linked deeply, or cannot be reached to check, the claim it would support does not get published as fact.
Inference is labelled as inference
Where we reason from a source rather than quote it, the page says so. A source that establishes a general rule is not cited as though it decided a specific parcel, and a pattern we see across jobs is described as our observation rather than as data.
Jurisdiction beats generalisation
Permits, fire-zone designations and code applicability are decided by a building department or a fire agency, not by a state code summary and not by a contractor. Where jurisdictions genuinely differ, we say that they differ rather than picking the answer that suits a bid.
We do not publish trust data we cannot verify
No review counts, ratings, certifications, award claims or credentials appear anywhere on this site — in the visible copy or in the structured data — unless they are real and on file. The code enforces this: a build gate fails if the trust file is incomplete or if the structured data would emit an empty rating.
Language that overclaims is treated as a defect
An automated scanner flags phrases like "fireproof", "maintenance-free", "guaranteed", "lifetime warranty", "#1" and blanket "code-compliant" across the whole library on every change, and the count is ratcheted — it is allowed to fall and not to rise. Noncombustible is not fireproof, and we write it that way every time.
A worked example: the Chapter 7A correction
For nearly two decades California’s wildfire exterior rules lived in Chapter 7A of the Building Code. In the 2025 Title 24 cycle the state deleted that chapter and moved its provisions into the standalone California Wildland-Urban Interface Code, governing permits applied for on or after 1 January 2026. Most of the internet — this site included — went on citing the deleted chapter.
In August 2026 we audited the whole library and found the deleted chapter cited as current law on 160 guides and across our location pages, with 141 guides deep-linking the superseded 2022 edition of the code. We corrected every one of them, repointed the citations to the current edition, and rewrote the anchor text on 65 links that described the old chapter while pointing at the new code. The advice on those pages had not been wrong — a wall that complied before generally still complies — but the authority behind it was, and that is enough to be worth fixing at that scale.
We mention it because a standards page that only describes intentions is not worth much. This is what the standard looks like when it costs something.
What we do not claim
We are a siding contractor. We are not a code official, a fire agency, an insurance adjuster, or an attorney, and our guides say so wherever the question crosses into one of those. We will read your parcel against the published maps and tell you what we think the scope is. We will not issue a determination that a building department, a fire agency or a court is the one to make. Where a question needs a professional we are not, the honest answer is to say which professional.
Found something wrong?
Tell us. If a code citation is stale, a link is dead, or a fact has been overtaken by a rulemaking, we would rather hear it than keep publishing it. Corrections to technical content are made on the page itself rather than quietly removed, and the date the page was last substantively revised is published in its structured data.
Last substantively reviewed: 2026-08-28.
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