How LandBrief works
Every number in a report comes from a named public source. This page documents each one — what it is, how we use it, and where it falls short — so you can judge how much weight to give it.
What happens when you run a report
When you enter an address, we first turn it into a precise location. Street addresses are geocoded through the U.S. Census Bureau geocoder; if you paste latitude and longitude directly (useful for raw land with no street address), we skip that step. From that single point, LandBrief queries a dozen federal, state, and county sources in parallel and assembles the answers into one report. The whole fan-out usually takes fifteen to sixty seconds — most of the wait is the government services themselves responding.
We label every value with its source. Where a report says something is "LandBrief's analysis," that means we computed it from the public data rather than reading it from a service — and we say so, because a calculation can inherit the errors of its inputs.
The sources, one by one
Flood — FEMA National Flood Hazard Layer
Flood zone, base flood elevation, vertical datum, mapped floodway velocity, and the FIRM panel number come from FEMA's National Flood Hazard Layer, the authoritative national flood-map dataset. We also flag when a parcel falls in a regulatory floodway. National coverage. What the flood zone means → · What the floodway restricts →
Terrain — USGS 3DEP LiDAR
The elevation-tinted relief image of the lot, its elevation range, the total fall across the parcel, and the average and maximum slope come from the USGS 3D Elevation Program. This is high-resolution LiDAR terrain, which is what reveals grading, building pads, and drainage swales the eye can't pick out from an aerial photo. National coverage where 3DEP is flown.
Soils — USDA SSURGO
Soil type, drainage class, hydric indicators, hydrologic group, depth to bedrock, seasonal water table, build-suitability ratings for homes, roads, and commercial buildings, steel and concrete corrosion, frost action, and Unified/AASHTO classification all come from the USDA Soil Survey (SSURGO) via Soil Data Access. USDA's own rating language is passed through unchanged. National coverage. How to read a soil rating →
Wetlands — USFWS National Wetlands Inventory
Wetland presence and its Cowardin classification (system, class, and water regime) come from the U.S. Fish & Wildlife Service National Wetlands Inventory. This is a screening inventory, not a jurisdictional determination. National coverage. What a wetland flag means →
Protected species — USFWS Critical Habitat
We flag when a parcel intersects federally designated critical habitat for a threatened or endangered species, which can add Endangered Species Act permitting considerations. From the USFWS critical-habitat dataset. National coverage.
Radon — EPA Map of Radon Zones
The county radon zone (1, 2, or 3) comes from the EPA Map of Radon Zones. It is a county-level prediction, not a measurement of the specific home. National coverage. What the radon zone tells you →
Natural-hazard risk — FEMA National Risk Index
The overall risk rating, the state percentile, and the individually elevated hazards come from the FEMA National Risk Index, which spans 18 natural hazards. It is scored at the county and Census-tract level. National coverage. How to read the risk index →
Opportunity Zones — U.S. Treasury / IRS designations
We check whether the parcel sits in a designated Qualified Opportunity Zone census tract and, if so, report the tract number. These designations are fixed federal geography. National coverage. What an Opportunity Zone means →
Aerial imagery — USDA NAIP
The photo with the approximate parcel outline uses public-domain USDA National Agriculture Imagery Program aerials. The boundary shown is approximate and is not a survey.
Parcel, value, and sale records — assessors and county GIS
Owner-occupancy signals, acreage, legal description, use class, assessed and market values, exemptions, tax detail, sale history, and deed references come from state and county property records. In Florida this is the Department of Revenue roll (with the sixteen largest counties self-hosted for speed); other covered states use their public statewide or county GIS. Sale-qualification decoding tells an arm's-length sale from a family transfer or a multi-parcel deed. Why the last price can lie →
Full property records are live in CO, CT, FL, MA, MD, ME, MN, NC, NJ, UT, VT, WA, and WI, with parcel boundaries and acreage in DE, MT, RI, and TN. The flood, terrain, soil, wetland, radon, hazard, species, and Opportunity-Zone layers above work in all 50 states.
Comparable sales and construction cost — LandBrief analysis
Nearby comparable sales are drawn from the same public sale records. Construction hard-cost estimates are LandBrief's calculation from published cost baselines, shown alongside a county new-home benchmark from the U.S. Census Building Permits Survey. Both are ballparks for orientation, explicitly labeled as our analysis — not a contractor bid or an appraisal.
What this means for accuracy
Most of these datasets are mapped at landscape or county scale, not lot scale. A flood line, a soil boundary, or a wetland edge can fall differently on your actual parcel than the map shows. County records can lag reality, and a headline sale price can reflect a transfer that was never an open-market sale. LandBrief tells you what the record says and, just as importantly, what to verify and who to ask. It is a screening tool — a fast, free first pass — not an official determination. Only the responsible authority's determination is authoritative.
Privacy, briefly
We don't require an account or an email to run a report, and the address you search isn't tied to your identity. The property location is sent to the public data providers to retrieve records — never any personal information about you. The full detail is in our Privacy Policy.
See it on a real address
Run any U.S. address or a lat/long, and watch these sources come together into one report. Free, no account, nothing stored.
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