What does ‘developable’ really mean?
A site is developable when three things line up: planning permission is realistically achievable, nothing physical or legal stops it being built, and the finished scheme is worth more than it costs to deliver. Fail any one and the land may still have value, but not as development land.
Most sites have at least one constraint. The question is usually not whether a problem exists, but whether it can be solved at a cost the scheme can bear. The table below summarises the checks buyers run.
| Check | What a buyer looks at |
|---|---|
| Access and highways | A safe junction, visibility and a link to adopted road |
| Planning policy | Allocation, settlement boundary, Green Belt and other designations |
| Flood risk | Flood zone, surface water and drainage options |
| Ground conditions | Contamination, old mine workings, made ground, slopes |
| Utilities | Water, sewer and electricity capacity and connection cost |
| Ecology and biodiversity | Protected species, habitats and biodiversity rules |
| Trees | Tree Preservation Orders, conservation areas, root zones |
| Heritage | Listed buildings, conservation areas, archaeology |
| Title and covenants | Ownership, restrictive covenants, third-party rights |
| Rights of way | Public footpaths and private rights crossing the site |
| Neighbours | Overlooking, daylight, outlook and noise |
| Viability | Whether the numbers still work after all of the above |
Can the site be reached safely from a road?
Access is often the first thing that stops a site. The highway authority will want a safe junction with enough visibility in both directions, a road width suitable for the number of homes, and a connection to a road that is adopted, meaning maintained at public expense. Visibility depends on traffic speed, so a fast rural road needs much longer sightlines than a quiet residential street.
If the only route in crosses land you do not own, or a narrow strip separates your land from the road, a third party may control much of the site's value. Our guide to access and ransom strips explains how to check your position.
Does planning policy support new homes here?
Planning decisions are made in line with the development plan unless other considerations indicate otherwise. Start with whether the land is allocated for housing, inside or next to a settlement boundary, or within a protected designation such as Green Belt, a National Park or an Area of Outstanding Natural Beauty.
In England, the revised National Planning Policy Framework published on 17 August 2026 says development within settlements should be approved unless the adverse effects substantially outweigh the benefits. Outside settlements, development can gain support in specified circumstances, for example where the council cannot show a five-year housing land supply or its Housing Delivery Test result is below 75%, or for sites within reasonable walking distance of a well-connected station. Some Green Belt land may also qualify as grey belt. The Framework also expects plans to allocate at least 10% of their housing on sites of one hectare or less, and a further 10% on sites of between one and 2.5 hectares, which can help smaller sites come forward.
In Wales, decisions follow Planning Policy Wales, Future Wales: the National Plan 2040 and the council's Local Development Plan. There is no grey belt in Wales, and new sites usually enter the system through the candidate-site stage of an LDP review. The Planning (Wales) Act 2026 received Royal Assent on 27 April 2026, and its provisions are being brought into force in stages.
Is the land at risk of flooding?
In England, the Flood Map for Planning places land in Flood Zone 1 (low probability), Zone 2 (medium) or Zone 3 (high) for flooding from rivers and the sea. National policy steers new homes towards lower-risk land first through the sequential test. A flood risk assessment is needed in Zones 2 and 3, and for some sites in Zone 1. Surface water flooding matters too, even in Zone 1.
In Wales, the equivalent is the Flood Map for Planning published by Natural Resources Wales, used with Technical Advice Note 15. Its zones include an allowance for climate change, and in higher-risk areas applicants must show through a Flood Consequences Assessment that development can be made safe over its lifetime.
Are the ground conditions and utilities workable?
Ground conditions usually affect cost more than feasibility. Former industrial land may be contaminated, some areas have old mine workings, soft or made ground may need piled foundations, and steep slopes need retaining walls. Each adds cost that comes straight off the land value.
Utilities work in a similar way. A site needs water, foul and surface water drainage, electricity and usually telecoms. The question is capacity and distance: a new substation or a long sewer connection can be expensive, and in some areas the network itself may need upgrading before new homes can connect. Buyers often ask the water company and the electricity network operator about capacity early, because their answers can shape both the cost and the timetable.
Which environmental checks apply?
- Ecology: surveys for protected species such as bats, great crested newts and badgers are often needed, and some can only be carried out at certain times of year.
- Biodiversity net gain in England: most developments must deliver a 10% gain in biodiversity, with significant gains maintained for at least 30 years. From 6 August 2026, non-major sites of 0.2 hectares or less are exempt unless priority habitat is affected.
- Biodiversity in Wales: the English metric does not apply. Planning Policy Wales expects development to deliver a net benefit for biodiversity.
- Water quality: in some English catchments, Natural England advises that new homes must be nutrient neutral. In Wales, phosphate-sensitive river SAC catchments can restrict or delay housing.
- Trees: works to trees protected by a Tree Preservation Order need the council's consent, and six weeks' notice must be given before work to trees in a conservation area. Both rules apply in England and Wales.
Could heritage, title or neighbours cause problems?
Heritage: listed buildings, conservation areas, scheduled monuments and archaeology do not stop development outright, but they shape what can be built and may need specialist reports.
Title and covenants: check who owns every part of the site, whether restrictive covenants limit building, and whether anyone has rights over the land, such as drainage easements or rights of way. Title registers and plans for most registered land in England and Wales can be downloaded from HM Land Registry. Covenants can sometimes be released by agreement, insured against or discharged by the Upper Tribunal.
Rights of way: a public footpath across the site does not prevent development, but it may need to be kept, designed around or formally diverted.
Neighbours: overlooking, loss of daylight and outlook can limit how many homes fit, especially on garden and backland plots.
Does the scheme still make money?
After every constraint is costed, the scheme still has to be viable. The finished value must cover build costs, planning obligations, fees, finance and a reasonable profit, with enough left to pay a price the landowner will accept. Our guide to how developers value land explains the arithmetic.
You do not need to commission all of these reports before talking to a buyer. A free, no-obligation site appraisal from us is a sensible first step, and there is nothing to pay us. Share any reports you already have, as they help build an accurate picture.
Questions
Can land outside a settlement boundary ever be developed?
Sometimes. In England, the August 2026 NPPF allows support for development outside settlements in specified circumstances, such as where a council cannot show a five-year housing land supply. In Wales, land outside settlement limits is usually brought forward through a Local Development Plan review. Either way, it carries more planning risk.
Is land in Flood Zone 3 undevelopable?
Not always, but it is much harder. In England, housing in high-risk areas usually has to pass the sequential test and often the exception test as well. In Wales, Technical Advice Note 15 and the Flood Map for Planning set the approach. Often only the lower-risk part of a site is built on.
Do I need surveys before I contact a buyer?
No. Most buyers review a site from maps, planning records and title documents first, then commission detailed surveys if they decide to proceed. Paying for expensive reports yourself is rarely necessary at the start, although any reports you already hold are useful to share.
Can a restrictive covenant stop development?
It can, if it prohibits building or limits the number of homes. Options include negotiating a release with whoever has the benefit, title indemnity insurance where the risk is low, or an application to the Upper Tribunal to discharge or modify it. A solicitor should review the title early.
Sources
- Flood zones and what they mean – Flood map for planning (GOV.UK)
- Flood map for planning (Natural Resources Wales)
- Understanding biodiversity net gain (GOV.UK)
- Consent under Tree Preservation Orders (Planning Portal)
- Get information about property and land (GOV.UK)
This guide is general information, not legal, planning or tax advice. Always take independent professional advice on your own circumstances.