Data sources and licences
All data is from the Federal Housing Finance Agency (FHFA) and the US Census Bureau. As works of the United States government the files are in the public domain (17 USC §105). No API keys are used; every file is a public bulk download. This build uses FHFA's quarterly release through 2026 Q2, FHFA's annual release of March 31, 2026 and Census permits through August 2026.
| File | Used for |
|---|---|
| FHFA HPI master file (quarterly, traditional, all-transactions and purchase-only) | Nation, states and metropolitan areas, 1975 to 2026 Q2. Hero lines and latest-quarter changes. |
| FHFA annual HPI, national and states | Annual index family used for every span comparison; updated March 31, 2026. |
| FHFA annual HPI, core based statistical areas | Metro and micropolitan area pages and comparison columns (developmental). |
| FHFA annual HPI, counties | County pages and comparison columns (developmental). |
| FHFA annual HPI, five-digit ZIP codes | ZIP code pages (developmental). |
| Census Building Permits Survey, county files | Monthly units by structure size, latest 60 months; annual 1995–2025. |
| Census Building Permits Survey, place files | Monthly units by structure size, latest 24 months; annual since 1995. City pages. |
| Census Building Permits Survey, state files | State monthly and annual totals. |
| Census population estimates, vintage 2025 | County, state and incorporated-place populations for per-1,000 rates. |
| Census 2020 ZCTA to county relationship file | ZIP code to county assignment (largest land share). |
| Census/OMB July 2023 CBSA delineation file | County to metro assignment and metro/micro status. |
FHFA's HPI datasets page and the Census Bureau's Building Permits Survey are the authoritative presentations. Home Value Trail is not affiliated with or endorsed by FHFA, the Census Bureau or any federal agency.
Not used
The American Community Survey (Census API) and the HUD USPS ZIP crosswalk (HUD User API) are listed in the site's plan as optional context; neither is used in this build, so no API notice applies. No commercial valuation data, listing data or property-level records are used.
Reuse
Tables and figures on this site may be quoted with a link to the page. The underlying data is public domain and best obtained from FHFA and the Census Bureau directly.