Every number, score, and risk flag in houseflipr has a source. We believe you should know where your data comes from — and how to apply the right level of confidence to it.
Every source we use is either a licensed API subscription, a free public government dataset, or a service with explicit commercial-use terms. We tag data with its source throughout the UI so you always know what you're looking at and can calibrate accordingly.
What we get
Active for-sale property listings, Zestimate, nearby sold comparables, days on market, and price reduction history.
Why we use it
Zillow has the most comprehensive US residential listing database. The Zestimate (Zillow's automated valuation model) is used to validate ARV when available, replacing our internal estimate with real market data.
How we access it
We subscribe to Zillapi — a licensed data partner that provides structured access to Zillow's listing feed via their API. We do not scrape Zillow. All data is used in compliance with Zillow's data licensing terms.
Shown as "Zillow" on map markers, alert cards, and property listings throughout the app.
What we get
Flood zone designation for any US address: Zone X (minimal risk), Zone AE/A (100-year floodplain), Zone VE (coastal high-velocity).
Why we use it
Flood zone is one of the most critical and overlooked factors in a flip. Zone AE properties require flood insurance ($1,500–3,000/yr), significantly narrow the buyer pool, and can prevent conventional financing — all of which kill deal margins.
How we access it
We query FEMA's free public government API using the property's latitude/longitude. No API key required. Data is maintained and updated by FEMA on their standard revision cycle.
Shown as a "FEMA" badge on the flood zone indicator in every deal analysis.
What we get
Real neighborhood statistics at the census tract level — vacancy rate, owner-occupancy rate, median household income, median year housing was built, poverty rate, and total population. Updated annually from the American Community Survey 5-year estimates.
Why we use it
Neighborhood data is a critical but often overlooked part of flip analysis. High vacancy signals distress. Low owner-occupancy shifts your buyer pool toward investors rather than families. Housing age predicts deferred maintenance. These numbers come from the US government, not guesses.
How we access it
Two-step process: (1) Census Geocoder API converts the property's latitude/longitude into a FIPS state/county/tract code. (2) ACS 5-Year API queries that specific census tract. No cost — we use a registered API key (free from census.gov).
Shown as "US Census ACS 5-Year" in the Neighborhood tab of every analysis.
What we get
Converts city names and plain-language locations into coordinates. Used when the AI Search advisor finds properties by city — e.g. "flip opportunities in Cedar Park, Texas."
How we access it
We query Nominatim with countrycodes=us to enforce US-only results. No API key required. Per Nominatim's usage policy, we send a User-Agent header identifying our application.
What we get
The intelligence behind every score, verdict, profit estimate, ROI, and deal recommendation you see in houseflipr.
Why we use it
This is our secret sauce — and we mean that literally. The Flip Score Engine is what separates a serious investment tool from a generic calculator. It's the product of real-world flipping knowledge, rigorous financial modeling, and market patterns distilled into a single number. The score tells you in seconds what would take an experienced investor hours to work out on a spreadsheet.
How it works
We're keeping this one close to the vest. What we can say: it considers more than a dozen weighted financial factors, has been validated against real-world deals, and produces results experienced investors trust. The algorithm is proprietary — that's the point.
Every score, verdict, profit figure, and deal recommendation in the app comes from this engine.
What we get
Government-owned FHA foreclosure properties currently available for purchase. HUD acquires these homes after an FHA-insured mortgage defaults. Typically sold below market to recover the foreclosure claim quickly.
How we access it
We query HUD's official GIS infrastructure — the eGIS ArcGIS MapServer (egis.hud.gov) — using a spatial bounding-box query around the search location. This is a free, public government REST API that requires no key. Listing price lives on HUDHomeStore.gov — we link to it directly from each HUD property card.
Shown as orange "HUD" pins on the Property Map and as a "HUD Foreclosures" section in Daily Alerts.
Data accuracy disclaimer: houseflipr aggregates data from third-party sources and presents it for informational purposes only. Listing data may be delayed, incorrect, or incomplete. ARV estimates are algorithmic and should be validated with local comparable sales. FEMA flood maps may not reflect current ground conditions. Always conduct independent due diligence — including professional inspection, title search, and consultation with a licensed real estate professional — before making any investment decision.