As the global human population has increased, and people have moved from rural to urban communities, so towns and cities have expanded, spreading along roads in ribbon developments and through the creation of low-density suburbs surrounding older, inner neighbourhoods.
It has long been recognised that it can be beneficial to control this urban sprawl:
The notion of a ‘green belt’ was first mooted in 1580, when Elizabeth I established a three-mile wide cordon sanitaire around London, prohibiting housing development where there had not been a building in living memory. By all accounts this proclamation was widely ignored.
In January 1914, Aston Webb, architect of the Victoria and Albert Museum and the facade of Buckingham Palace, told his peers at the London Society that he foresaw, in the year 2014, “a beautiful sylvan line practically around all London.” He named it the ‘green belt’, an improvement on its original working-title, the ‘green girdle.’
In 1938, the Green Belt (London and Home Counties) Act enabled local authorities to purchase and protect land from development, creating a green belt around London. The Act also allowed landowners to enter into covenants protecting their own land as part of the green belt.
The green belt was subsequently sanctioned in Patrick Abercrombie’s Greater London Plan (1944) and established in the Town and Country Planning Act in 1947, designed to hold in check urban sprawl and protect the countryside from increasing urbanisation.
Green Belts establish a buffer zone between urban and rural land, separating town and country and preserving land for forestry, agriculture and wildlife where environmental conditions can be improved and conservation encouraged.
Green belt land now covers around 13 per cent of England, approximately 1.6 million hectares (ref. CPRE: Green Belts in England: Key facts). A map of green belt land can be seen on the Telegraph website.
In 1998, in order to limit development on ‘green' and undeveloped land in general, the UK Government set a target for 60% of all new development to be on brownfield land (land which has previously been developed).
Planning Policy Statement 3 (PPS3) published in 2006, 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. Brownfield briefing: Coalition stresses commitment to brownfield).
 Pressure on the green belt
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 likely to increase further 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 750000 housing gap by 2025).
The National Planning Policy Framework (NPPF) published in March 2012 did not include a brownfield target, and 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 the housing demand. He said that 9% of England had been built on, but this needed to increase to 12%.
“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”. Boles 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 2012, the green belt was nearly 32,000 hectares smaller than it was in 2003 (ref. Telegraph).
- 'to check the unrestricted sprawl of large built-up areas;
- to prevent neighbouring towns merging into one another;
- to assist in safeguarding the countryside from encroachment;
- to preserve the setting and special character of historic towns; and
- to assist in urban regeneration, by encouraging the recycling of derelict and other urban land.'
However, it suggests that 'New Green Belts should only be established in exceptional circumstances, for example when planning for larger scale development such as new settlements or major urban extensions.'
The NPPF explains that local authorities should define green belt boundaries in their local plans and that these should only be changed in exceptional circumstances. It sets out considerations that should influence the positioning of green belt boundaries, and lists certain types of development that may not be inappropriate on green belt land, such as facilities for outdoor sport.
On 6 October 2014, DCLG published additional guidance making clear that once they have been established, green belt boundaries should only be altered in exceptional cases, and that this should be done through the preparation or review of the Local Plan. Housing need does not justify harm to the green belt. For more information see Green belt planning practice guidance.
On 16 October 2014, Communities Secretary Eric Pickles said: "I am crystal clear that the green belt must be protected from development, so it can continue to offer a strong defence against urban sprawl." (Ref. New rules further strengthen green belt protections 16 October 2014.)
However, in April 2016, Communities Secretary Greg Clark approved outline proposals for a major development, including 1,500 new homes, in the Gloucestershire green belt, deciding that is was justified due to “very special circumstances”. This was because of unmet local housing demand, longstanding strategic planning aims in the area and the economic benefits of the proposal. (Ref. gov.uk 1 April 2016.)
In July 2017, it was reported that 425,000 homes were due to be built on the green belt, an increase of 54% since March 2016. The Campaign to Protect Rural England (CPRE) warned that government funds are rewarding the development of green belt land that ministers have promised to protect.
In March 2018, the Ministry of Housing, Communities and Local Government (MHCLG) reported that the green belt in England belt totalled 1,629,510 hectares (12.5% of the land area of England), down slightly on March 2017, when there were 1,634,580 hectares. (Ref. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/745368/Green_Belt_Statistics_England_2017-18.pdf)
In September 2019, the government announced nearly £2 million for local authorities to crack down on illegal developments on the green belt. https://www.gov.uk/government/news/cash-boost-to-crackdown-on-illegal-building-on-nation-s-green-belt
The green belt is not universally supported. Some see it as a barrier to growth and suggest that it is unreasonable to continually demand that more housing is constructed whilst simultaneously protecting the green belt. Others suggest that protection of the green belt means our cities become more and more dense, pushing up property prices.
It is also argued that green belts do not protect the 'countryside', they protect industrial agriculture, where vast, mono-cultural, biologically barren fields are created that discharge rainwater into our rivers which then flood over-dense urban centres. Some suggest that a more dispersed, lower-density development would encourage more widespread and varied green spaces, providing better wildlife habitats and helping attenuate rainwater run-off.
Think tanks such as the Adam Smith Institute have called for the total abolition of the green belt, arguing that the release of a strip of green belt land half a mile wide around London would provide for 800,000 new homes. Their calls are supported by more moderate organisations such as Centre for Cities and the London Society.
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.'
NB: It is important to differentiate between the green belt and 'greenfield' which are often confused. Greenfield developments are those which take place on sites that are not constrained by any existing buildings or infrastructure. Clearly this need not be within the protected green belt.
 Related articles on Designing Buildings Wiki
- Amberfield land.
- Areas of Outstanding Natural Beauty.
- Blue belt.
- Blue space.
- Brownfield land.
- Designated sites.
- Ecological network.
- Garden cities.
- Garden suburb.
- Green belt planning practice guidance.
- Green infrastructure.
- Green roof.
- Green space.
- Greenfield land.
- Making the Green Belt work for London.
- Metropolitan open land (MOL).
- National parks.
- National planning policy framework.
- Parleys Canyon Wildlife Bridge.
- Patrick Abercrombie.
- Safeguarding land.
- Sites of Special Scientific Interest.
- The future of the green belt.
- The green belt and historic buildings.
- Types of land.
- Windfall site.
 External references
- CPRE: Green belts.
- CPRE: Green Belts: A greener future (summary).
- CPRE: Green Belts in England: Key facts.
- Telegraph: Interactive green belt map.
- Telegraph: Government minister warns We must develop a third more land to meet the housing demand
- Natural England: Green belt publications.
- Natual England: Green infrastructure.
- BBC: Open land can solve housing shortage, says minister.
- Written ministerial statement by Local Government Minister Brandon Lewis about permissions for traveller's sites on green belt land. 17/1/2014.