Developing Brownfield Land Sites

Have you considered a brownfield development? The main challenge is often the cost of getting the land ready: demolishing existing buildings and decontaminating the site, with extra costs up front and possible delays. But it is worth considering.

Some definitions

A brownfield site is land or buildings that have been previously developed and are now unused, derelict or contaminated.

A greenfield site has not been developed before. Green Belt is designated to protect open land around towns and cities.

What is brownfield development?

We have all seen sites with redevelopment potential:

• Buildings with broken windows and vegetation growing in and around them
• Empty shops at the end of the high street that have not been re-let
• Vacant hoarded sites covered in fly-posters
• Disused warehouses and car parks turning into waste ground

Utilities are usually already in place, even if you change the layout, and not every site is badly contaminated.

A policy priority

Brownfield sites can carry contamination risk, so they are not always a developer’s first choice. But government policy strongly supports bringing previously developed land back into use, and councils publish Brownfield Land Registers of sites suitable for housing.

Types of contamination

Contamination is any substance that is or may be harmful to people or buildings, including corrosive, explosive, flammable, radioactive or toxic substances.

Common issues include:

• Asbestos: in older buildings, pipe insulation, fireproofing and buried building debris
• Carcinogenic chemicals: cyanide and phenol at former gasworks; arsenic from mining; mercury from incinerators; benzene from solvents and burning coal and oil
• Corrosive substances: acids and sulphates from chemical and manufacturing works
• Gases: methane, hydrogen sulphide and carbon dioxide from landfill
• Heavy metals: cadmium in many London garden soils and waste sites; lead from printing, paint and dye works; copper and zinc from sewage treatment
• Oils and tars: from oil storage and distribution sites
• Petrol and diesel: from petrol stations, repair and MOT garages and car showrooms

Risk is assessed on the seriousness of the hazard and the likelihood of harm to people, wildlife, groundwater, foundations and building fabric, and of spreading to surrounding land.

The benefits

Experienced developers are not put off, and specialist lenders regularly fund these projects. What matters is the site’s previous use, what may be below ground and your track record on similar sites.

With national targets of around 300,000 new homes a year, there is pressure to find sites. Despite remediation costs, brownfield land often has infrastructure in place and offers the chance to transform a neighbourhood or improve a street, which adds value to the new homes.

Why it’s not quite that easy

Remediation can be expensive, especially on former industrial land, and contamination can be buried deep, so a full ground investigation before purchase is critical.

Sites are not always where housing demand is, unless a whole area is being regenerated. Planning can be delayed while remediation is agreed. And some brownfield sites have higher biodiversity than farmland, as nature quickly colonises undisturbed urban land, which can raise planning issues.

3 planning tips for brownfield sites

1. Building on previously developed land preserves green space, supporting policies to green cities, manage storm water and reduce flood risk.
2. Brownfield sites usually have established infrastructure: transport, water, telecoms and schools.
3. Councils are usually supportive in principle of redeveloping long-vacant brownfield land, whereas they resist losing greenfield or public open space.

Permitted development rights

Since 1 August 2021, Class MA permitted development allows many Class E commercial uses to change to residential through prior approval rather than a full planning application, provided the conditions are met. Class E includes:

• Shops, banks and estate agents
• Restaurants and cafes
• Gyms
• Offices and light industrial units
• Research and development
• Clinics, health centres and nurseries

Permitted development rights also allow up to two additional storeys on certain existing blocks of flats. Airspace schemes still need the existing structure to carry the extra load, and legal and practical issues must be considered.

In summary

Don’t dismiss brownfield sites when looking for your next development. Just check feasibility carefully, including a full ground investigation, before committing time and money.