What Is a Greenfield Site?
What greenfield sites are, how they differ from brownfield land, and the planning challenges involved in developing them.
In the UK planning system, the distinction between greenfield and brownfield land is one of the most important factors in determining whether a site will get planning permission for development. Understanding what greenfield means - and the planning hurdles involved - is essential for anyone looking to build or invest in new development.
What Is a Greenfield Site?
A greenfield site is land that has not previously been built on. This typically means agricultural fields, meadows, woodland, or other undeveloped land on the edge of towns and villages. The term is not formally defined in planning legislation, but it is widely used and understood by planning authorities, developers, and the public.
In practice, "greenfield" is defined by what it is not - it is not previously developed land (brownfield). The National Planning Policy Framework (NPPF) defines previously developed land as land that is or was occupied by a permanent structure, excluding agricultural or forestry buildings, and land in built-up areas such as residential gardens.
Greenfield vs Brownfield
The distinction matters because national and local planning policy strongly favours developing brownfield land before greenfield:
| Feature | Greenfield | Brownfield |
|---|---|---|
| Previous use | Undeveloped - agriculture, woodland, open land | Previously built on - former factories, offices, garages |
| Planning policy | Generally protected; develop only when brownfield insufficient | Strongly encouraged for redevelopment |
| Contamination | Usually none | May need remediation |
| Infrastructure | Often needs new roads, utilities, drainage | Usually has existing connections |
| Ecology | May have habitats, hedgerows, protected species | Ecology usually less complex |
| Community opposition | Often significant - "building on green fields" | Usually less opposition |
| Land cost | Often cheaper per acre before planning permission | Higher per acre, but planning support stronger |
Greenfield vs Green Belt
Greenfield and Green Belt are not the same thing. This is a common source of confusion.
- Greenfield simply means land that has not been built on. A greenfield site could be anywhere - inside or outside a Green Belt, inside or outside a settlement boundary
- Green Belt is a specific policy designation around major cities, designed to prevent urban sprawl and keep land permanently open. Development in the Green Belt is restricted to very special circumstances
A field on the edge of a village that is not in the Green Belt is greenfield but may still be developable if the local plan allocates it for housing. A field in the Green Belt is both greenfield and Green Belt - facing the strictest protection of all.
Planning Policy and Greenfield Land
The NPPF sets out a clear hierarchy that favours brownfield development:
- Councils should prioritise brownfield land for housing and other development
- Councils must maintain a brownfield land register of suitable sites
- Greenfield sites should only be released for development when there is insufficient brownfield land to meet housing needs
- Councils must demonstrate a 5-year housing land supply - and if they cannot, the presumption in favour of sustainable development tilts toward approving applications, even on greenfield sites
This last point is crucial. In areas where the council cannot demonstrate a 5-year housing land supply, greenfield sites that are well-located and sustainable can and do receive planning permission - sometimes against the council's wishes, on appeal.
When Greenfield Development Gets Approved
Greenfield development is most likely to succeed when:
- The local plan allocates the site - if the council has identified the land for development in their local plan, this provides strong policy support
- The council lacks a 5-year housing land supply - triggering the NPPF's "tilted balance" in favour of sustainable development
- The site is adjacent to an existing settlement - not isolated in the countryside
- There are no overriding constraints - such as Green Belt, SSSI, flood zone 3, or significant heritage assets
- The proposal includes community benefits - affordable housing, infrastructure, public open space
You can check how your local council performs on housing delivery and land supply using Planning Signal - councils that are behind on housing targets are more likely to approve greenfield applications.
Challenges of Greenfield Development
Even where policy supports greenfield development, there are practical challenges:
Community Opposition
Greenfield proposals attract more objections than almost any other type of development. Residents value open countryside and often feel strongly about "concreting over green fields". A well-managed public consultation process can help address concerns, but opposition is almost inevitable.
Infrastructure Costs
Greenfield sites typically require new infrastructure: roads, drainage, utilities, and often contributions to schools, healthcare, and public transport. These costs are funded through Section 106 agreements and the Community Infrastructure Levy (CIL), but they can significantly reduce the viability of a scheme.
Environmental Considerations
Undeveloped land may support wildlife habitats, mature hedgerows, and watercourses. Environmental Impact Assessments (EIA) and ecological surveys are commonly required, and Biodiversity Net Gain (BNG) - now mandatory - means developments must deliver a 10% improvement in biodiversity.
Check whether the land is in or near a flood risk area before progressing - flood zones 2 and 3 require a flood risk assessment and may restrict the type of development permitted.
Landscape Impact
In Areas of Outstanding Natural Beauty (AONBs, now called National Landscapes), National Parks, and other designated landscapes, greenfield development faces additional scrutiny. Major development in these areas is only permitted in exceptional circumstances.
Greenfield Development and Housing Need
Despite the policy protection, greenfield land plays a significant role in meeting the UK's housing need. The government's target of 300,000+ new homes per year cannot be met through brownfield development alone - there simply is not enough previously developed land in the right locations.
This tension between protecting the countryside and building homes is at the heart of the UK planning debate, and it means that greenfield sites will continue to be developed, particularly in high-demand areas of southern England where brownfield supply is limited.
Tips for Assessing Greenfield Sites
- Check the local plan - is the site allocated for development? If not, is it within or adjacent to a settlement boundary?
- Check the 5-year land supply - if the council is short, the policy environment is more favourable
- Review constraints - Green Belt, flood zones, conservation areas, listed buildings nearby, ecology designations
- Look at recent decisions - has similar development been approved nearby? Search on Planning Signal to see what has been approved in the area
- Get pre-application advice - this is essential for greenfield proposals, given the policy sensitivity
Greenfield development is more complex than brownfield, but it is not impossible. With the right site, the right design, and a clear understanding of planning policy, greenfield land can and does get planning permission for housing and other development across the UK.