'Land which is or was occupied by a permanent structure, including the curtilage of the developed land (although it should not be assumed that the whole of the curtilage should be developed) and any associated fixed surface infrastructure. This excludes: land that is or has been occupied by agricultural or forestry buildings; land that has been developed for minerals extraction or waste disposal by landfill purposes where provision for restoration has been made through development control procedures; land in built-up areas such as private residential gardens, parks, recreation grounds and allotments; and land that was previously-developed but where the remains of the permanent structure or fixed surface structure have blended into the landscape in the process of time.'
In England, in 1800, just 10% of the population lived in towns and cities, now the figure is 90%. England is the third most densely populated major country in the world, and our population is projected to increase from 52 million in 2010 to 62 million in 2035 (ref ONS: Population Projections). In 2011, a report from the Institute of Public Policy Research warned of a housing black hole, suggesting that there would be a a shortfall of 750,000 homes by 2025. (Ref IPPR: England faces 750,000 housing gap by 2025).
This puts our land under considerable pressure for development, and yet our urban areas have vacant sites with hoardings around them, unused buildings with broken windows, closed-down shops, factories and warehouses and car parks sprawling across waste ground. Meanwhile there is new building on open ‘green’ land at the edge of almost every town and city.
The Environment Agency suggests that 'Concentrating development on brownfield sites can help to make the best use of existing services such as transport and waste management. It can encourage more sustainable lifestyles by providing an opportunity to recycle land, clean up contaminated sites, and assist environmental, social and economic regeneration. It also reduces pressure to build on greenfield land and helps protect the countryside.' (ref Environment Agency: Position Paper 2003).
In 2009, local authorities identified an estimated 61,920 ha of previously-developed land (PDL) in England (Ref Homes and Communities Agency. Previously developed land that might be available for development).
In 1998, in order to combat urban sprawl, and make better use of derelict sites, the UK Government set a national target for 60% of all new developments to be built on brownfield land. In 2006, PPS3 re-stated this commitment, making clear that local authorities should 'take stronger action' to bring brownfield land back into use, and in 2010, it was estimated that 76% of new dwellings were built on previously-developed land (ref BrownfieldBriefing).
However, in June 2010 PPS3 was revised, removing gardens from the definition of brownfield land, to prevent what it characterised as 'garden grabbing' (ref Parliament: Briefing Papers). NB This would seem to conflict with the government's current intention to extend permitted development rights to allow extensions in gardens without planning permission.
The National Planning Policy Framework (NPPF) published in March 2012 did not include a brownfield target, but rather it encouraged '...the effective use of land by reusing land that has been previously developed (brownfield land), provided that it is not of high environmental value...’, leaving local authorities to ‘…consider the case for setting a locally appropriate target for the use of brownfield land.’
The NPPF also permits ‘…limited infilling or the partial or complete redevelopment of previously developed sites (brownfield land)...' within the green belt '…which would not have a greater impact on the openness of the green belt and the purpose of including land within it than the existing development.
In an interview on BBC2’s Newsnight in November 2012, planning minister Nick Boles, suggested that more than 388,000 hectares of open countryside would have to be built on to meet housing demand. He said that nine per cent of England had been built on, but this needed to increase to 12 per cent, 'We’re going to protect the green belt – but if people want to have housing for their kids they have got to accept we need to build more on some open land'. He only offered explicit protection for green belt land around towns and cities (ref Telegraph: Government minister warns We must develop a third more land to meet the housing demand).
In June 2014, plans were announced that would give pre-planning approval for housing on brownfield sites. Local authorities will be required to introduce Local Development Orders (LDOs) for brownfield sites suitable for housing that will amount to the granting of outline planning permission. Ref Government initiatives to help build more new homes on brownfield land 13 June 2014. It is suggested that this could provide up to 200,000 permissions for new homes by 2020
Chancellor George Osborne said, 'Local authorities will apply local development orders onto sites and we expect over 90% of suitable brownfield land to be covered by 2020.' DCLG later clarified that local authorities would decide which sites should be subject to LDOs. Ref Planning Resource 4 July 2014.
On 28 October 2014, the government published figures which they said showed that, 'Following reforms of the planning system, more than two thirds of all homes are built on brownfield land.' Ref Brownfield sites to be prioritised for development.
In November 2014, the Campaign to Protect Rural England (CPRE) and the University of the West of England (UWE) published From Wasted Space to Living Spaces, which reported that councils had identified capacity for at least 1 million new homes on brownfield land.
In July 2015, the government plan for growth, Fixing the foundations: creating a more prosperous nation, proposed introducing a new zonal system to give ‘automatic’ planning permission in principle on suitable brownfield sites.
On 4 January 2015, a £1.2bn fund was announced to prepare brownfield sites for the construction of starter homes in the next 5 years. This is intended to fast-track the creation of at least 30,000 new starter homes and up to 30,000 ‘market’ homes on 500 new sites by 2020. See Government to commission affordable homes on publicly owned land for more information.
In February 2016, housing charity Shelter published a report 'When brownfield isn't enough' in which they suggest, 'Building on some bits of the green belt should be an option, if done right. Smaller, controlled release of appropriate bits of green belt land could deliver substantial numbers of new homes.'
 Types of brownfield land
There are four main categories of a Brownfield land:
- Partially occupied or utilised.
The Home and Communities Agency states that '...of the estimated 61,920ha of brownfield land in England, 54% was derelict or vacant, while the remainder is in use but with potential for redevelopment.' (2009 figures)
Depending on whether there is contamination present, the preparation of brownfield land can be problematic and expensive. Problems include:
- Threats to human health.
- Damage to flora and fauna.
- Contamination of ground water.
- Damage to foundations and structures.
- Migration of contaminants to adjacent land.
Depending on the previous usage of land, different types and levels of contamination can be found:
- Former landfill sites and gasworks can result in the presence of cyanide and phenol.
- Former waste disposal sites may contribute significant amounts of cadmium.
- Cadmium can also be found in garden soils, especially in the capital.
- Mineralisation and sewage treatment can result in zinc and copper contamination.
- Mining and smelting can result in arsenic contamination.
In more complicated cases, the history of a site might not be fully known and it may not be certain what chemicals may be present. Before development starts therefore, detailed research may be necessary, which can be time consuming and expensive. Tests may be based on soil samples taken at a variety of depths and locations in order to determine the nature and level of contamination as well as its extent. Initially, this is likely to be at least 9 samples per hectare. but more testing may be necessary depending on what is found.
 Site restoration
There are three main clean-up techniques:
- Excavation and removal of contaminated soil followed by either disposal or off-site treatment.
- Limiting the spread of the contamination (for example 'pathway interdiction' using a high density polythene membrane to encapsulate the contaminants. This option is chosen if other techniques result in unrealistic costs or create potential hazards).
- Using a treatment to destroy, remove or detoxify containments.
The main types of soil treatment are:
- Biological treatment.
- Thermal treatment / desorption (using heat to increase the volatility of contaminants so they can be removed).
- Chemical immobilisation / stabilisation / solidifitation.
- Washing (injecting clean water and extracting contaminated water).
- Soil vapour extraction using vacuum extraction (this is particularly effective with volatile chemicals such as petrol and chlorinated solvents).
Biological treatment, also known as bioremediation, is the most common technique. It utilises microorganisms and plants and is particularly suitable for fuel-based contaminants. Microbes 'eat' the chemicals found in oil spills, digesting them to produce water and carbon dioxide. For the bacteria to grow, the right temperature, nutrients and amount of oxygen must be provided. This can be achieved by pumping in air and other substances such as molasses. In some countries the cold weather conditions means that the soil has to be excavated and cleaned above ground with the help of heaters, and an oxygen supply. Bioremediation allows cleaning on site, generally it does not require much labour or equipment and so is usually cheaper than other methods.
Although some solutions are cheaper than others, the cost of site investigation and soil treatment is still significant. Developers suggest that it should be up to the government to cover the cost of cleaning up contaminated land, otherwise, the need to pass on costs to purchasers means that it will not always be possible to provide affordable housing on brownfield sites.
See Contaminated land for more information.
 Related articles on Designing Buildings Wiki
- Amberfield land.
- Brownfield registers.
- Building on fill.
- Common land.
- Contaminated land.
- Deleterious materials.
- Government to commission affordable homes on publicly owned land.
- Green belt.
- Green belt planning practice guidance.
- Greenfield land.
- Ground heave.
- Housing zones.
- Local development orders.
- Land banking.
- Landfill tax.
- National planning policy framework.
- Methane and other gasses from the ground.
- Mixed use development.
- Pink zones.
- Right to contest.
- Smart cities.
- Solid and liquid contaminants risk assessments.
- Urban decay.
- Windfall site.
 External references
- Wildlife and Countryside Link, Guidance for brownfield land of high environmental value. 2015
- Gov.uk, Enough brownfield land released to build 68,000 homes and support 135,000 jobs. 20 February 2014.
- Homes and Communities Agency: Brownfield and public land.
- Environment Agency: Position statement. 2003.
- Homes and Communities Agency. Previously developed land that might be available for development. 2009.
- Environmental Protection Act.
- English Partnerships: Towards a National Brownfield Strategy (2003)
- ONS: Population Projections.
- Planning Minister Nick Boles on BBC2’s Newsnight. November 2012.
- Telegraph: Government minister warns We must develop a third more land to meet the housing demand.
- Brownfield Briefing.
- Scottish Natural Heritage: The importance of wildlife in cities. October 2013.
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