RE/TERM provides market intelligence derived from public government datasets, Zillow Research public data, and Federal Reserve economic series. This page discloses every data source used, how values are calculated, and what this tool cannot tell you.
RE/TERM uses publicly available CSV files published by Zillow Research at files.zillowstatic.com. These files require no API key or data agreement. They are fetched nightly at 3am UTC via a scheduled serverless function and cached in Netlify Blob Storage. Users receive cached data — not a live query — which is refreshed once daily.
| Series | What It Measures | Frequency |
|---|---|---|
| ZHVI | Zillow Home Value Index — smoothed, seasonally-adjusted median for homes at the 35th–65th percentile. Includes all homes in the area, not just those recently listed or sold. Metro and ZIP level. | Monthly |
| ZORI | Zillow Observed Rent Index — repeat-rent methodology tracking the same units over time, all bedroom types. Metro level. | Monthly |
| ZHVF | Zillow's 12-month home value forecast. This is Zillow's proprietary model output — RE/TERM does not independently verify or validate this forecast. Metro level. | Monthly |
The Terminal tool uses live data from the St. Louis Federal Reserve's FRED API. All series are publicly available. Data is fetched at session start.
| Series ID | Description | Source |
|---|---|---|
| MORTGAGE30US | 30-year fixed mortgage rate (Freddie Mac PMMS) | Freddie Mac / FRED |
| MORTGAGE15US | 15-year fixed mortgage rate | Freddie Mac / FRED |
| DGS10 | 10-year Treasury constant maturity yield | U.S. Treasury / FRED |
| CSUSHPINSA | S&P/Case-Shiller U.S. National Home Price Index | S&P Dow Jones / FRED |
| HOUST | Housing starts (new privately-owned units, thousands) | U.S. Census / FRED |
| PERMIT | Building permits authorized (thousands) | U.S. Census / FRED |
| MSACSR | Monthly supply of new homes (months) | U.S. Census / HUD / FRED |
| HSN1F | New single-family homes sold (annual rate) | U.S. Census / FRED |
| FIXHAI | Housing Affordability Index (NAR methodology) | NAR / FRED |
| MSPUS | Median sales price of houses sold in the United States | U.S. Census / HUD / FRED |
| EXHOSLUSM495S | Existing home sales (seasonally adjusted annual rate) | NAR / FRED |
| RVUUS | Rental vacancy rate, U.S. | U.S. Census / FRED |
| CUUR0000SEHA | CPI: Rent of Primary Residence (used for rent adjustment) | BLS / FRED |
ZIP-level demographic and housing data is sourced from the ACS 5-Year Estimates, 2023 vintage (covering survey years 2019–2023). This dataset is accessed via the public Census API at api.census.gov. No authentication key is required.
Variables used: median home value (B25077), median household income (B19013), median contract rent (B25058), population (B01003), owner/renter tenure (B25003), gross rent (B25064), rent burden (B25071).
Fair Market Rent data is sourced from the U.S. Department of Housing and Urban Development via the HUD User API. RE/TERM uses FY2026 FMRs (effective October 1, 2025). FMRs are published at the metropolitan area or county level — a single FMR applies to all ZIP codes within a county.
HUD FMR represents the 40th percentile of gross rent for unassisted units. It is not the same as median market asking rent. Well-maintained units in desirable sub-markets will typically rent above FMR.
If the HUD API is unavailable, RE/TERM estimates FMR from Census gross rent using bedroom-scaling ratios. Estimated values are clearly labeled.
Metro-level migration patterns are sourced from IRS SOI Tax Stats, which tracks year-over-year address changes on tax returns. The most recently available data is FY2022. This data is embedded directly in the tool and is not fetched live. It may not reflect migration pattern changes since 2022.
RE/TERM estimates an active listing price range from ZHVI using a days-adjusted premium band. Active listings trade above the ZHVI index because they represent currently available, select inventory rather than the full stock of all homes. The premium varies with market velocity.
| Days to Pending | Premium Band | Market Condition |
|---|---|---|
| < 15 days | +25% to +40% above ZHVI | Extreme sellers market |
| 15–30 days | +18% to +30% above ZHVI | Sellers market |
| 30–50 days | +10% to +22% above ZHVI | Balanced-to-seller |
| 50–70 days | +5% to +15% above ZHVI | Balanced-to-buyer |
| > 70 days | −2% to +8% above ZHVI | Buyers market |
The days-to-pending figure used is a metro-level average. Individual ZIPs within a metro may have faster or slower absorption rates. This estimate is not sourced from MLS data and does not represent actual active listing prices.
The Terminal adjusts Census home values forward using the S&P/Case-Shiller HPI (CSUSHPINSA) or a metro-level HPI when available from FRED. The adjustment factor is the ratio of the current HPI to the HPI at the approximate Census survey midpoint (mid-2021).
This adjustment is a statistical approximation. It applies a national or metro-wide index to a specific ZIP — local sub-market conditions may differ materially. The adjustment factor and data source are displayed as a tooltip in the Terminal.
This is a gross yield only. It does not account for vacancy, CapEx reserves, property management, taxes, insurance, or financing costs. Use the Deal Analyzer for net cash flow analysis.
This is a derived signal, not a published series. It represents the risk premium above the 10-year risk-free rate that the mortgage market is demanding.
The Deal Analyzer uses standard real estate investment finance formulas. All inputs are provided by the user. RE/TERM does not populate property tax, insurance, or other expense fields from any data source — these must be entered manually from county records and quotes.
| Limitation | Impact |
|---|---|
| Census data lag (2–3 years) | Home values and income from Census ACS reflect 2019–2023 survey data. In appreciating markets, Census home values may be significantly below current conditions. HPI adjustment applied in Terminal mitigates but does not eliminate this gap. |
| ZHVI is not a listing price | ZHVI includes all homes, not just listed or recently sold properties. Active listings will show higher prices. Listing range estimate is derived, not from MLS data. |
| Days-to-pending is metro-level | Listing premium bands use metro-level days-to-pending. Individual ZIP codes within a metro may have meaningfully faster or slower absorption. Sub-market conditions are not captured. |
| HUD FMR is county-level | A single FMR applies to all ZIP codes within a county. High-demand sub-markets within a county will typically see asking rents above FMR. |
| ZHVF is Zillow's model | The 12-month home value forecast is produced by Zillow's proprietary algorithm. RE/TERM does not modify or independently validate this forecast. Past forecast accuracy varies by market. |
| Migration data lag | IRS SOI migration data reflects FY2022. Migration patterns may have shifted in 2023–2026 due to remote work normalization, rate-driven affordability changes, or other factors. |
| No property-level data | All data is area-level (metro, county, or ZIP). Individual property values, conditions, histories, or assessments are not available. |
| Embedded city data is manually maintained | Days-to-pending, inventory months, and property-type breakdown figures for the 16 tracked metros (Miami, Austin, Atlanta, Phoenix, Charlotte, Dallas, Denver, Nashville, Seattle, New York, Los Angeles, Chicago, Boston, Houston, Las Vegas, Tampa) are updated manually on a monthly basis. Values may lag recent market shifts by up to 30 days. |
All listing price ranges shown on RE/TERM are estimates derived from the ZHVI index using the days-adjusted premium methodology described above. They are not sourced from active listings, recently sold comparables, or any MLS system.
For actual current listing prices and recently sold data, use:
RE/TERM is built and maintained by Victor De la Cruz, CPA, through Milairo. While the tool incorporates CPA-grade thinking around real estate tax concepts (§280A, Schedule E, DSCR, depreciation), nothing on RE/TERM constitutes professional financial advice, investment advice, tax advice, or legal advice.
The Deal Analyzer produces mathematical outputs based on user-provided inputs. These outputs are illustrative. Actual investment performance will differ based on market conditions, financing terms, tenant behavior, capital expenditure timing, local regulations, tax law changes, and many other factors not modeled by this tool.
Before making any real estate investment decision, consult:
The ZIP choropleth map on the Analytics page uses ZIP Code Tabulation Area (ZCTA) boundary polygons from the U.S. Census Bureau's 2020 Cartographic Boundary Files. These are publicly available shapefiles at 1:500,000 scale, optimized for web mapping use.
These boundaries are uploaded to Mapbox as a vector tileset and served as pre-tiled map tiles. The boundary data is static and updated only when Census releases new ZCTA vintages (typically following each decennial census). ZIP code boundaries do not precisely match USPS delivery routes — they are statistical approximations.
All maps on RE/TERM are rendered using Mapbox GL JS, an open-source mapping library. Map tiles are served by Mapbox under their standard tile hosting terms. The base map style uses Mapbox's public light style. The ZIP choropleth layer uses a private vector tileset hosted on the RE/TERM Mapbox account.
Mapbox usage is subject to their Terms of Service. No user location data is collected or transmitted in connection with map rendering.
If you identify an error in any data displayed on RE/TERM, or have a question about the methodology described on this page, contact us at hello@re-term.com.
RE/TERM is a free tool built and maintained by Milairo. It is provided as-is without warranty of any kind. Use of this tool constitutes acknowledgment that you have read and understood the limitations described on this page.