At Home with Nature: Encouraging biodiversity in new housing developments

The London Assembly’s latest report, ‘At Home with Nature: Encouraging biodiversity in new housing developments’ published in Jan 2017, delivers the latest findings from the Housing Committee which scrutinises the Mayor’s role and record in delivering the private, social and affordable homes London needs.

Summary

There is a risk that London will see its biodiversity being squeezed or reduced as planners and developers try to increase housing density in the city. Nature provides physical, mental, social, environmental and economic benefits for city dwellers, but both flora and fauna are rapidly decreasing in UK cities. The Mayor has an important role in ensuring biodiversity is enhanced and new habitats are created, as London attempts to tackle the housing crisis.

Biodiversity is part of national, regional and local planning policies. Collectively, these policies provide a good overall strategic vision for providing for nature in London. Unfortunately, these policies are not always translated at ground level.

Some European cities explicitly recognise the importance of green infrastructure and the environmental, social and economic benefits it provides. Several cities have introduced a planning tool called a ‘green factor’ or ‘green space factor’ (GSF) to ensure a minimum level of greenery in new developments. This planning tool has increased levels of green space and improved resilience to flooding and climate change impacts in these cities.

There are inconsistences at borough level when it comes to approving planning applications. This is due to lack of ecology expertise within planning departments and other pressures, for example housing target pressures, which can impact on the decisions of the authority. Funding cuts have reduced the capacity of planning departments.

Developers are sometimes uncertain of the steps needed to promote biodiversity and therefore the cost of doing so. The historic emphasis on protecting key species sometimes worries developers and mean some avoid biodiversity entirely. However, some developers clearly do value biodiversity on their sites and include biodiversity adaptations and green infrastructure where it is feasible. The inclusion of biodiversity and green infrastructure in a site has been shown to increase the chances of receiving planning permission with fewer conditions, positively affecting prices paid and speeding up the rate of sales.

This report explores the current situation and offers some potential solutions to ensure that London maintains and improves on its current levels of biodiversity, as it continues to grow and change.

Recommendations

London is still one of the greenest cities in the world but, in the rush to tackle the housing crisis, there is a risk that opportunities to protect and enhance local flora and fauna are being lost. In order to build the homes that London needs, a large proportion of these homes will be built on brownfield land and at higher densities. An increased housing density could lead to a more fragmented environment for nature, reducing biodiversity and access to nature for Londoners.

Although nature provides physical, mental, social, environmental and economic benefits for urban dwellers, both flora and fauna are rapidly decreasing in UK cities. The 2016 State of Nature report showed that, in the UK, 56 per cent of species are in decline and 7 per cent of urban species are threatened with extinction. For example, London’s hedgehog population has dropped by 50 per cent since 2000. This is a further concern for London government as nature can also improve the city’s resilience to climate change and can help mitigate issues associated with high density living, such as flooding and the urban heat island effect, thereby generating financial savings in the long term.

The Mayor has an important role in ensuring biodiversity is enhanced and new habitats are created. A large proportion of new homes will be built on public land and will be subject to Mayoral planning approval if they are of potential strategic importance to London. This means that the Mayor can, and should, push for higher requirements for biodiversity on these sites in order for planning permission to be granted.