Selling brownfield land: contamination, registers, PiP and conversions

What counts as brownfield land?

In England's National Planning Policy Framework (NPPF), brownfield means previously developed land: land that has been lawfully developed and is or was occupied by a permanent structure, including associated fixed surface infrastructure. Large areas of lawfully laid hardstanding can count even without buildings, although it should not be assumed that the whole curtilage can be built on.

The definition excludes land last occupied by agricultural or forestry buildings; residential gardens, parks and allotments in built-up areas; land with restoration requirements, such as former mineral workings; and land where the remains have blended into the landscape.

Both nations favour reuse. England's NPPF gives substantial weight to schemes that remediate contaminated land or make better use of vacant and underused land and buildings. Planning Policy Wales tells councils to prioritise suitable and sustainable previously developed land before greenfield sites.

How do contamination and remediation affect a sale?

Many brownfield sites carry some contamination from past uses, such as fuel storage, workshops, made ground or asbestos in buildings. In England and Wales, the environmental regulators expect historic land contamination to be managed using the Land Contamination Risk Management (LCRM) guidance, which has three stages: risk assessment, options appraisal, and remediation and verification.

A buyer will usually want at least a desk study, and often intrusive ground investigation, before committing, and councils commonly attach planning conditions requiring investigation and remediation. Remediation costs reduce what a buyer can pay, so contamination rarely stops a sale outright, but it does change the price and the contract terms. Share any reports you already hold, check whether a buyer can rely on them or whether they need updating, and ask your solicitor how responsibility for contamination will pass on sale.

What are brownfield land registers and Permission in Principle?

These are English planning tools; they are not available in Wales.

• Brownfield land registers: each English council keeps a register of previously developed land suitable for housing. Part 1 lists sites of at least 0.25 hectares, or able to support at least five homes, that are suitable, available and achievable. Land entered in Part 2 of the register is granted Permission in Principle.
• Permission in Principle (PiP): owners can also apply for PiP directly for housing-led schemes of fewer than 10 homes on sites under one hectare, with a decision target of five weeks. It establishes that a site is suitable for a specified amount of housing-led development. Building cannot start until technical details consent is granted, and that application must be made within three years of PiP unless a condition sets a shorter period.

A site on a register or with PiP is easier for a buyer to assess, but the buyer will still check access, ground conditions and the technical details.

Does vacant building credit reduce affordable housing?

In England, policy HO8(4) of the NPPF provides vacant building credit. Where a vacant building is brought back into use or replaced, any affordable housing contributions due should be reduced by a proportionate amount, equivalent to the gross floorspace of the existing buildings. It does not apply to buildings that have been abandoned, or to major development on Green Belt land covered by the Golden Rules.

The credit can make a real difference to viability, so keep evidence of when the building was last used, such as leases, business rates bills or utility records, and avoid letting it slide into abandonment. In Wales, check your council's Local Development Plan and supplementary guidance for how existing floorspace is treated.

Can a commercial building become homes without full planning permission?

In England, Class MA permitted development allows a change of use from Class E (commercial, business and service) to homes, subject to prior approval. The current rules include:

• the building must have been in a qualifying commercial use for a continuous period of at least two years before the application
• the former three-month vacancy requirement and 1,500 square metre floorspace limit were removed in March 2024
• it does not apply to listed buildings, scheduled monuments, SSSIs, National Parks, National Landscapes (formerly areas of outstanding natural beauty), the Broads or World Heritage Sites
• the council assesses transport, contamination, flooding, noise, natural light, fire safety in taller buildings and, in conservation areas, ground-floor changes
• the conversion must be completed within three years of prior approval

Some councils remove the right with Article 4 directions, so always check locally. Class MA does not apply in Wales.

Should I demolish buildings before I sell?

Usually not without advice. In England, demolition is often permitted development, but you must first apply to the council for a decision on the method of demolition and any restoration of the site, then wait for its answer or 28 days. Demolishing an unlisted building in a conservation area needs planning permission, and pubs, live music venues and theatres are excluded from the right.

Demolition can also remove value. Clearing a building may end the floorspace that vacant building credit relies on, or a conversion route such as Class MA. Many buyers prefer to demolish as part of their own scheme. If a building is unsafe, take advice on securing it: the demolition right does not apply where someone with an interest in the land let the building become unsafe and repair or temporary support could have made it safe.

How is selling brownfield land different in Wales?

The principle is the same, because Planning Policy Wales puts previously developed land first. The tools are different:

• there are no brownfield land registers or Permission in Principle, so the route is usually an LDP allocation or a planning application
• Wales still uses older use classes, such as A1 shops and B1 business, and has no Class E or Class MA, so changing offices to homes needs planning permission
• the mandatory biodiversity net gain metric does not apply, but Planning Policy Wales expects a net benefit for biodiversity
• drainage for more than one home, or a construction area of 100 square metres or more, needs approval from the council's SuDS Approving Body before work starts
• sites near rivers or the coast should be checked against the Flood Map for Planning and, in some river catchments, phosphate limits

Our guide to selling development land in Wales covers these points in more detail.

How does viability shape what a buyer can pay?

Buyers work out a residual value: the value of the finished scheme, minus build costs, abnormal costs such as remediation, demolition and drainage, planning obligations, fees, finance and a profit margin. On brownfield sites, the abnormal costs often decide the price. Our guide to how developers value land explains this step by step.

Some national rules help smaller sites. In England, since 6 August 2026, non-major sites of 0.2 hectares or less are exempt from mandatory biodiversity net gain unless priority habitat is affected. England's NPPF also gives substantial weight to temporary uses of previously developed land where other development is expected within a reasonable time.

If you own a yard, depot, garage court or redundant commercial building, see what we look for in brownfield land. Our site appraisal is free and carries no obligation.

Questions

Sources

• NPPF Annex B: Glossary (GOV.UK)
• Land contamination risk management (GOV.UK)
• Permission in principle (Planning Portal)
• The Town and Country Planning (Brownfield Land Register) Regulations 2017, explanatory note (legislation.gov.uk)
• GPDO 2015 Schedule 2 Part 3 Class MA (legislation.gov.uk)

This guide is general information, not legal, planning or tax advice. Always take independent professional advice on your own circumstances.