Since 1995, Countrywide estimates 96,000 new homes have been built on the green belt equating to around 3.5% of the 2.7 million homes built in England between 1995 and 2014.
The number of new homes built on the green belt each year has halved since the early 2000s, falling from a peak of 6,700 homes in 2001 to 3,248 in 2014.
The trend started before the downturn too. Despite a 36% rise in the number of homes built in England between 2001 and 2007, the numbers built on the green belt fell by 46%.
Last year just 3,250 homes (3% of all homes) were built in the green belt, down on 2013 and the long run average.
Over the past five years development on green belt has increasingly been on land surrounding growing cities in southern England – reflecting the demand for housing and a wider trend of new home delivery concentrated in the South of England.
In 2014 the 1,575 new homes built on the London green belt, accounted for 48% of all green belt development in England, up from 38% a decade ago. London has also seen the most homes built on the green belt since 1995, 39,100.
Local authorities can grant permission for development in the green belt in special circumstances where the benefit from development outweighs perceived harm to the green belt.
While there is debate and conflicting guidance about specifics broadly these may include significant economic benefits, replacing buildings and in some instances housing or other social need.
Johnny Morris, group research director at Countrywide, said: “While development is generally prohibited within the green belt a small number of homes are given permission to be built.
“Many of these development sites would be at odds with common perceptions of green belt.
“Rather than picturesque countryside being concreted over, these sites were either brownfield, infill schemes or unused land with little amenity value.
“Sustained pressure, particularly in the South, to get more homes built and government plans to take a tougher line on local authorities with out of date plans, will likely see more homes built on green belt in future years. Just returning to the rates of development on green belt seen in the early noughties would yield an extra 5,000 new homes a year.”
Research by Countrywide published earlier in 2015 showed around the 80 railway stations in the green belt on the fringes of cities across England, there is enough unused land in areas within walking distance of those train stations to accommodate nearly half a million new homes.
Morris added: “Given the chronic shortage of new homes in certain areas, we concluded we may not have the luxury of overlooking these potential sites.”