Building footprints across your coverage area, as polygons.
A footprint layer vectorised from very high resolution imagery and refreshed each year, ready to sit under your parcels, your address points and everything else you join to it.
Spec
- Platform
- VHR satellite / aerial
- GSD
- VHR, 0.5 m or finer
- Spectral band
- RGB
- Cadence
- annual refresh
- Formats
- GeoJSON or Shapefile
- Delivery unit
- tile grid or administrative boundary
- Content
- geometry only
Files and fields
- File
Footprint layer
- Format
- GeoJSON or Shapefile
- What's in it
- One polygon per structure across your national or regional coverage area, drawn on the roof outline as seen from above. Geometry only: the shape and location of each footprint, with no use, type, storeys or height attached. Your own attributes, address points and parcel references join on afterwards.
- File
Tile-grid or boundary delivery
- Format
- one file per tile or per administrative unit
- What's in it
- The layer is cut the way you load it, by tile or by administrative boundary, so each piece can be ingested, validated and rolled back on its own. Tell us the grid or the unit list and the files follow it.
- File
Annual refresh
- Format
- yearly re-extraction
- What's in it
- The whole coverage area is extracted again on a yearly cycle from newly captured imagery. This is a refresh cycle with one release a year, so it slots into a national publication or a product build and does not behave like a feed. An area under persistent cloud can arrive later than the rest.
- File
Release notes
- Format
- text file per delivery
- What's in it
- Lists which areas were refreshed and which are delayed, with the reason. Where cloud held an area back, the note says so, so the gap is in the paperwork before it turns up in a join.
How it works
You supply the coverage area
A national or regional boundary, or a list of administrative units, plus the format, the coordinate reference system and the tile structure you load.
We capture and extract
Annual VHR imagery is captured across the area. Structures are segmented in the RGB imagery and vectorised into polygons.
You get the layer
Footprints come back in your format and tile structure, with release notes. You ingest them, overlay parcels and address points, and run your own checks against the ground truth you hold.
The next year
The same coverage area is extracted again on the annual cycle. Run it against last year's layer to see what was built or pulled down.
Limits
- Condition
Small and hidden structures
- Effect on the layer
- A pixel at 0.5 m is half a metre on the ground. A house roof is many pixels across and resolves cleanly. A garden shed or a lean-to is only a few, and a shed under tree canopy or a heavily occluded outbuilding can be missed. Densely packed buildings can be merged into one polygon. No completeness percentage is published.
- Condition
Tall buildings and roof overhang
- Effect on the layer
- Footprints follow the roof as seen from above. Overhang and building lean can move a footprint off the true ground outline, most visibly in dense urban cores with tall buildings.
- Condition
Cloud
- Effect on the layer
- Persistent cloud over an area can delay that area's refresh. The release notes list what was delayed.
- Condition
Geometry only
- Effect on the layer
- The layer carries no use class, building type, height or age. Those come from other layers you hold.
- Condition
Annual, not continuous
- Effect on the layer
- A building completed after the year's capture appears at the next refresh, and a demolition does the same. There is no change-only update stream between releases.
Why this exists
Most footprint layers are digitised by hand a few map sheets at a time, or stitched from open datasets captured in different years. The seams show where one source ends and the next begins. New estates are missing and demolished buildings are still there. Every downstream team finds out when its own join fails: a parcel with no building, a height model with no outline to stand on. This delivers one layer, extracted the same way across the whole coverage area, on one yearly cycle.
Who it's for
For
- Geospatial data leads at national mapping agencies who need a current building layer to build from.
- Property-data providers that need one consistent base layer for parcel matching, attribute enrichment and height estimation.
- Data engineers who ingest GeoJSON or Shapefile into PostGIS or an enterprise geodatabase.
Not for
- Teams that need building use, type, storeys or height. This layer is geometry only, so that work needs other data.
- Survey-grade outlines of a single building. A ground or drone survey does that job.
- Continuous change feeds or near-real-time demolition and construction alerts. The cycle is annual.
Technical and procurement questions
Is coverage complete?
No, and we publish no completeness percentage. Small, occluded and densely packed structures can be missed or merged.
Does it include building use or type?
No. Footprint shape and location only.
How close is a footprint to the ground outline?
The footprint follows the roof. Overhang and lean can shift it from the ground outline, more so for tall buildings.
Which formats and projections do you deliver?
GeoJSON or Shapefile, cut by tile or administrative boundary. Tell us the coordinate reference system you load and we will deliver in it.
How do we check it against our own data?
Overlay it on your parcels, your cadastre or a survey sample you trust, and count what is missing or merged. We can scope a pilot area for that comparison before you commit to a whole country.
Does cloud cover create gaps?
Yes. Persistent cloud can delay an area's refresh, and the release notes say which.
How often does it update?
Once a year, as a refresh cycle.
Can we load it straight into our pipeline?
The files are plain GeoJSON or Shapefile, cut the way you partition your own loads, so a tile can go into PostGIS or your geodatabase without a reshaping step. Run your usual validity and overlap checks on the first delivery, as you would on any new source.
Who owns the delivered layer?
Use and ownership terms for the delivered layer are written into the contract before work starts. The imagery sources keep their own licences.
How is it priced?
Each coverage area is scoped and quoted on its own, with a written scope you can take through procurement.
Send us the coverage area.
Or .
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