How we research and verify

Official sources only

We cite city and county building departments, consolidated city-county governments, state statutes and administrative codes, state agencies and licensing boards, and federal agencies. Model-code text (such as the International Residential Code) is quoted only from government-hosted copies: a state register, an agency PDF, a city ordinance or a city handout. Municipal code hosts are used only where the city links to them as its official code. Blogs, permit services, contractors, lead-generation sites and AI summaries are never cited.

Every fact is a quote

• Each fact is stored with the exact sentence or table cell it comes from, the source address, the date the source shows and the date it was checked.
• Quotes are copied character for character; “[...]” marks a cut and nothing is added inside quotation marks.
• Fees are quoted, never computed. The fee calculator applies a city’s published formula and shows that formula next to the result.
• If a page could not be opened without bypassing a block, we did not use it.

Two independent readers

A first reader extracts each fact. A second reader re-opens every source and confirms or corrects every quote, number and date. A place is published only when its second-reader report is complete; inside it, only facts that were confirmed or corrected appear. Facts with conflicting sources, blocked sources or open questions are held back until resolved, and are never shown.

Today the published data holds 24,559 verified facts from 2,319 official sources. Before each build, every quote is matched again against the archived copy of its source.

Building permit vs zoning

Project pages keep the building-permit rule and the zoning rule separate. A threshold number is always shown next to the sentence it comes from, because the conditions in that sentence (where it is measured, what it does not cover) are part of the rule.

Keeping it current

• Fees, contacts and code editions are re-checked at least every 180 days, statutes at least every 365 days. Facts older than that are not published.
• Each page shows a “Last checked” date: the newest check among the sources it cites.
• New places appear as their verification is completed.

What we do not do

We explain rules; we do not give legal advice or decide whether your particular project is exempt. Building officials can interpret their codes, and local amendments, overlays and HOA covenants can add requirements. Found an error? See corrections.