Developers told they should plant ‘urban forests’

Council hopes to put green rivals in shade by using planning permission rules to increase tree quotas

DEVELOPERS will be required to plant “urban forests” that provide tree cover over a quarter of their new estates under pioneering plans.

Wycombe council in the Chilterns is to become the first in Britain to require developers to plant enough trees so their canopies cover at least 25 per cent of the land on any new estate – or risk being refused planning permission. If successful, it is seen as a model for councils nationwide.

Planners chose 25 per cent because of research showing it is the “tipping point” between being classed as a poor rather than a leafier prosperous neighbourhood, using multiple indices of social deprivation.

The move also follows new research demonstrating the value of urban trees in combating pollution, reducing flood risk, cooling heat spots and improving biodiversity.

The Wycombe plan is the brainchild of Philip Simpkin, the council’s natural environment officer, who mapped tree canopy coverage in the borough against seven different indices of social deprivation including education and health.

“It’s not causative but a correlation [was found] where the areas that were the most deprived had the least canopy cover,” said a spokesman. “Trees are not the only things that can improve an area but they are a simple way of trying to improve developments.”

To get planning permission, developers will be required to show how they will deliver at least 25 per cent tree canopy on new estates.

In the densest developments where it might be more difficult to plant the required number of trees, the council will accept alternatives such as “green” walls and roofs covered with grass, plants and shrubs that provide the same ecological benefit as trees. David Johncock, Wycombe’s cabinet member for planning, said: “We hope that in the future this may become the gold standard which others will follow.”

The proposal – part of the council’s strategic local plan – is seen as a measure that could be included in the National Planning Policy Framework to help fulfil Defra’s 25-year environment plan to plant 11million more trees. New national guidance from the Tree and Design Action Group (TDAG), which brings together planners, tree experts and professional bodies, will recommend all councils set tree cover targets.

The first map of tree cover in more than 280 cities and towns across Britain shows huge variation between the greenest – Farnham in Surrey with 45 per cent of its land covered by its tree canopy – and the lowest, which is Fleetwood in Lancs, at just 3.3 per cent.

Kieron Diock, head of the Forestry Commission’s urban forest research group, said: “There’s now such overwhelming evidence of the benefits of trees to people’s health, physical or mental.”