Data sources

Zillow Home Value Index (ZHVI), mid tier, smoothed and seasonally adjusted

• Publisher: Zillow Research
• Used for: Typical home value by ZIP, county, metro and state, and the price trend.
• Cadence: Monthly
• Read this build: 2026-08
• Licence and attribution: Zillow Research data, used with attribution: Data: Zillow Research (ZHVI, ZORI).
• https://www.zillow.com/research/data/

Zillow Observed Rent Index (ZORI), all homes plus multifamily, smoothed

• Publisher: Zillow Research
• Used for: Typical market rent by ZIP, county and metro, and the rent trend (tier A pages).
• Cadence: Monthly
• Read this build: 2026-08
• Licence and attribution: Zillow Research data, used with attribution: Data: Zillow Research (ZHVI, ZORI).
• https://www.zillow.com/research/data/

HUD Small Area Fair Market Rents, FY2026

• Publisher: US Department of Housing and Urban Development
• Used for: Rent by bedroom count for every ZIP. The rent used on tier B pages, and a reference on all pages. It is the 40th percentile gross rent, so it runs below market.
• Cadence: Annual (fiscal year starts 1 October)
• Read this build: FY2026
• Licence and attribution: US government work, public domain.
• https://www.huduser.gov/portal/datasets/fmr/smallarea/index.html

HUD Fair Market Rents by county, FY2027

• Publisher: US Department of Housing and Urban Development
• Used for: County rent by bedroom count on county pages.
• Cadence: Annual
• Read this build: FY2027
• Licence and attribution: US government work, public domain.
• https://www.huduser.gov/portal/datasets/fmr.html

American Community Survey 5-year estimates, 2020 to 2024 (B25103 median real estate taxes paid, B25077 median home value, B11001 households)

• Publisher: US Census Bureau
• Used for: Effective property tax rate (median taxes paid divided by median value) by ZIP code tabulation area, county and state; households for the permits ratio.
• Cadence: Annual (December)
• Read this build: 2020 to 2024
• Licence and attribution: US government work, public domain.
• https://www.census.gov/programs-surveys/acs/data/summary-file.html

Freddie Mac Primary Mortgage Market Survey, 30-year fixed (FRED series MORTGAGE30US)

• Publisher: Freddie Mac via the Federal Reserve Bank of St. Louis
• Used for: The weekly 30-year rate. The site adds a disclosed investor premium to it for the loan payment.
• Cadence: Weekly (Thursday)
• Read this build: 2026-09-24
• Licence and attribution: Freddie Mac data, cited with source.
• https://fred.stlouisfed.org/series/MORTGAGE30US

Building Permits Survey, county monthly files

• Publisher: US Census Bureau
• Used for: New housing units permitted in the last 12 months per 1,000 households, a supply-pressure signal.
• Cadence: Monthly
• Read this build: 2025-09 to 2026-08
• Licence and attribution: US government work, public domain.
• https://www.census.gov/construction/bps/

NAIC Homeowners Insurance Report, data for 2023

• Publisher: National Association of Insurance Commissioners
• Used for: Average HO-3 homeowners premium by state, multiplied by 1.2 as a landlord-policy assumption.
• Cadence: Annual
• Read this build: 2023
• Licence and attribution: Published statistics, cited with source.
• https://content.naic.org/sites/default/files/publication-hmr-zu-homeowners-report.pdf

Census Gazetteer, ZIP code tabulation areas (2026)

• Publisher: US Census Bureau
• Used for: Centroids for the nearby ZIPs table.
• Cadence: Annual
• Read this build: 2026
• Licence and attribution: US government work, public domain.
• https://www.census.gov/geographies/reference-files/time-series/geo/gazetteer-files.html

Terms checked

Zillow requires clear attribution of its research data to Zillow; every page that uses it carries "Data: Zillow Research (ZHVI, ZORI)" with a link to zillow.com/research/data. HUD and Census data are US government works. Freddie Mac's survey rate is cited to Freddie Mac through FRED. NAIC figures are cited to the report they come from.