Digging deeper
Putting the spotlight on the biggest issues in gardening today Planning legislation to help boost biodiversity
New planning rules to boost and protect natural habitat on the site of development projects could help to halt the decline of British wildlife. The legislation became mandatory in England from January and now forms part of planning regulations under the Town and Country Planning Act. Biodiversity rules are also to be introduced in Scotland, Wales and Northern Ireland.
The new planning rules in England, centred on the concept of Biodiversity Net Gain (BNG), oblige developers to not only protect habitat on site, but also demonstrate measures to boost biodiversity by 10 per cent.
Conservation charities say the legislation is long overdue. The State of Nature Report 2023 said that the UK is one of the most nature-depleted countries in the world: 16 per cent of species are threatened with extinction from Great Britain. Homebuilding and urban development are often cited as factors in these declines.
“All new developments should aim to be biodiverse and create green infrastructure, such as pollinator-rich gardens, native trees and new hedgerows,” says Rachel Hackett, Living Landscape
Development Manager at the Wildlife Trusts. “If done well BNG will offer a positive step forward in the way we think about nature and development in a more integrated way. But adding just 10 per cent more wildlife in a time of nature crisis is not enough. We want to see developers go beyond the minimum and aim for at least a 20 per cent gain for nature, with every single infrastructure project having a positive impact.”
Ahead of the new legislation, homebuilders have set up the Future Homes Hub – a scheme to promote joint working between builders, local government and conservation charities.
Many larger housing developers have already seized the initiative. “We’ve been in partnership with the RSPB since 2016,” says Helen Nyul, Head of Biodiversity at Barratt Developments. “It began at Kingsbrook – a 2,450-home development near Aylesbury
where around 60 per cent of the development is green space, with community orchards, meadows and a range of habitat features.”
Similarly, the Vistry Group has been working with charities to create habitats for bumblebees and bats within its developments, while Bellway Homes has entered a partnership with charity Plantlife – creators of No Mow May.
However, evidence suggests that private gardens are being squeezed by urbanisation. The Office of National Statistics says 12 per cent of British households have no garden at all, while the average garden size is now only 188m2 – about three-quarters the size of a doubles tennis court.
“Garden size requirements are set by Local Planning Authorities as part of Local Plan policies,” explains Alice Davidson, Senior Planning Manager at Vistry Group. “New BNG requirements would not in themselves require an increase in garden sizes as most new habitats would be in communal areas, along green walkways and so on.”
“Gardens are deliberately given quite a low value in the new biodiversity metric,” adds Neil Beamsley, Head of Biodiversity at Bellway Homes. “That’s because once the housebuilder has sold the property, it’s up to the owner what they do with that space. They could – in an ideal world – turn it into a mini nature reserve, which would be fantastic. But equally, they could choose to lay fake grass or pave it over.”
A joint research project from the RHS and the University of Sheffield in 2016 showed that around a quarter of the UK’s front gardens have been paved over, often for car parking; the current demand for house-adjacent electric-vehicle chargers looks likely to feed that trend.
Yet at neighbourhood scale, our gardens still play a key role in creating wildlife habitat. A 2023 review led by Professor Richard Delahay of the University of Exeter, concluded: “Although individual gardens are often small and highly fragmented, they collectively account for a significant proportion of urban green infrastructure. Gardens need to be managed in interconnected clusters, with canopy cover offering links to other habitats – hedgerows, mature trees and shrubs. Taken together they offer a greater contribution to urban biodiversity than the sum of their parts.”
The UK has become one of the most nature-depleted countries in the world