National coverage
Home project costs and permit rules by state
Permits are issued locally, but the code, the owner-builder rule and the fee level are usually set at the state layer. Start with your state, then drill to the county or city that actually reviews your application.
Model reviewed August 2026
States covered
51
all 50
Statewide codes
36
15 adopt locally
Projects modeled
57
per state
Population covered
335M
US residents
Featured state guides
Each guide covers permit rules, the code in force, typical costs and the counties and cities that review your application.
Most and least expensive states to build in
Modeled construction cost index vs the national baseline.
| Hawaii | +62% vs national |
|---|---|
| Alaska | +34% vs national |
| California | +31% vs national |
| New York | +28% vs national |
| Massachusetts | +26% vs national |
| Mississippi | -15% vs national |
|---|---|
| Arkansas | -13% vs national |
| Oklahoma | -13% vs national |
| Kansas | -12% vs national |
| West Virginia | -12% vs national |
Popular projects nationwide
Northeast
South
Midwest
Mountain West
West Coast & Pacific
Sources
Sources & verification
Model vintage August 2026. The links above are the issuing agencies' own pages — we publish them so you can confirm the current rule yourself, not as evidence that each fact on this page was re-checked with them today. Cost figures are modeled estimates based on national baselines adjusted for local labor and material pricing, not quotes. Permit rules change; confirm with the building department before starting work.