Greenfield vs Brownfield: The Difference, on a Map
A greenfield site is land that has never been developed: a field, a wood, a meadow at the edge of town. A brownfield site is land that was developed before and now sits vacant or underused, often with the slabs, sheds or contamination of its previous life still on it. The words also name two kinds of software project, and the last question on this page covers that.
The difference in one line
Greenfield has no past to deal with. Brownfield has one, and the cost of building there is the cost of dealing with it.
| Greenfield | Brownfield | |
|---|---|---|
| Built on before | No | Yes, and the use has ended |
| What is there now | Crops, grass, trees | Empty buildings, slabs, sealed ground |
| Cost before building | Roads, pipes, a planning fight | Demolition, ground investigation, clean-up |
| What planning policy says | Protect it | Reuse it first |
How each looks from the air
Greenfield reads as texture with no straight lines inside it: the stripes of a ploughed field, the mottled top of a wood, a hedge as the only edge.
Brownfield reads as geometry that has lost its purpose: rectangular slabs with weeds in the joints, a roof with holes, rail sidings that stop at nothing, fences around nothing.
The one that catches people out is mown grass. A gasworks capped and grassed twenty years ago looks like a park from the air. It is still brownfield, and the register says so.
How to tell them apart in QGIS
- Look at the imagery. Your national orthophoto or a satellite basemap, at about 1:2,000. Apply the two cues above.
- Look at the past. A historical imagery slider (IGN's Remonter le temps in France, USGS EarthExplorer in the United States). A parcel that had buildings in 1990 and none today is brownfield, whatever the grass says.
- Check the register. Cartofriches in France, the council's Brownfield Land Register in England, the EPA's Cleanups in My Community map in the United States. If the parcel is listed, the question is settled.
Questions people ask
Is a brownfield site always contaminated?
No. In British usage brownfield means previously developed, and a clean former car park qualifies. In American usage the word implies possible contamination, because the 2002 federal act defines it that way. For a specific site, only a ground investigation answers.
What is a friche?
The French word for a brownfield site. Since 2021 it has a legal definition in the planning code, and the national inventory is Cartofriches, run by Cerema.
What do greenfield and brownfield mean in software?
A greenfield project starts from nothing. A brownfield project changes a system that is already running, with all its constraints. Same metaphor: one is a clean site, the other has a past to work around.
The QGIS AI hub collects what AI can and cannot do inside QGIS. The other pair of words that gets mixed up on a permit, site plan vs plot plan, has its own page.
