WorkLotRights
LotRights: what you can build on your lot, from public records
Per-address property reports for Fairfax County, Virginia. Every item is cited to the record it came from and given a confidence level. 6DOTS built it and runs it.
Visit lotrights.comWhat it is
Two reports for one address. Expansion Rights answers “what can I build?”: the zoning district and overlays, setbacks, height and coverage from the ordinance in force, a buildable-envelope estimate on the map, easements, floodplain and Resource Protection Area, permits and septic files, and an action plan for the project you name. 45 items.
Home Check answers “what is on record for the home I own or am buying, and where does the record disagree with what is on the ground?”: permit history against the improvements the county taxes, well and septic files, structures against yards and easements, utilities and buried-tank indicators. 30 items.
Each item says what the public record shows, how much to trust it, where it came from, and which county office or licensed professional can confirm it. It is informational only: not a survey, a zoning determination, a title report, or a legal or engineering opinion, and the report never calls anything illegal. It says what record was and was not found.
The problem
A homeowner thinking about an addition, a second story, an accessory living unit, a garage, a pool or a lot split has two options: read the zoning code themselves, or pay a surveyor and an attorney before they know whether the project is even possible. Buyers under contract have days before a contingency expires. Listing agents get asked “can I build on it?” and answer with a guess.
The public record already holds most of the answer. Fairfax County publishes parcel geometry, zoning, overlays, easements, floodplain, soils, permits and plats. It is spread across dozens of systems, in four different parcel-number formats, with no citations and no statement of how far to trust any of it.
What we built
An address goes in. It is matched in the county's Master Address Repository, resolved to a parcel, and checked to confirm county zoning governs it. A free Snapshot comes back in seconds. The Full Report pulls 58 county, state and federal sources for that parcel, keeps every request and its retrieval time, and renders the findings as a web report, an interactive map and a PDF.
Ordinance values come from the zoning ordinance amendment in force, versioned by effective date with the section cited next to each number. The buildable envelope is computed from county parcel geometry with the district's yards applied per edge, reproducible to the square foot, and labelled a GIS-derived estimate. Every number in a report is one of three things: sourced, computed, or an estimate.
On the Verified tier, a Virginia-licensed professional reviews the recorded plats, easements and covenants, confirms or rejects each affected finding, and signs an addendum scoped to exactly what it covers. Where the county has a septic As-Built drawing on file, it is pulled and placed on the map.
- Next.js 16 and React 19 on Vercel
- TypeScript, pnpm and Turborepo monorepo
- Supabase: Postgres, PostGIS, pgmq queues, Storage, Auth
- MapLibre maps
- Playwright-rendered PDFs from the same report pages
- Node report worker on Fly.io
- Stripe checkout
- Anthropic API for narratives and document extraction
- 58 public data sources per parcel
- 383 tests replaying recorded county responses
Where it stands
- Live at lotrights.com for parcels under Fairfax County zoning. The towns of Vienna, Herndon and Clifton and the cities of Fairfax and Falls Church have their own ordinances and are not covered.
- The Snapshot is free. A Full Report is $199 and a Verified Report is $1,490; a Verified Home Check is $990. Per report, per address, one-time, no subscription.
- Verified reports are sold only while a Virginia-licensed reviewer is accepting work.
- Built in September 2026: the data research on September 7, the Expansion Rights report from September 8, Home Check on September 14, payments on September 15.
Own or buying a home in Fairfax County? Start with the free Snapshot at lotrights.com.
Have public data that should be a product?
LotRights went from research to a cited, paid report in under three weeks. We take a small number of client builds like it.