Reducing reliance on offsite biodiversity units: A guide for housebuilders

  • Eco expert encourages developers to utilise innovative solutions
  • Homes located within 100 metres of green spaces could add £2K more value

As the UK moves forward with mandatory Biodiversity Net Gain (BNG) regulations for new developments, ecology experts at Thomson Environmental Consultants share guidance on how housebuilders and urban planners can maximise on-site biodiversity and reduce the need for offsite biodiversity units.

Data shows that since 1970, UK species have declined by an average of 19%, with nearly 1 in 6 species now threatened with extinction, many of which are found in areas targeted for development¹. Additionally, homes located within 100 metres of green spaces are, on average, £2,500 more valuable than those situated 500 metres away², demonstrating the economic benefits of incorporating biodiversity into new developments.

Gregor Neeve, Associate Director of the Nature Markets team at Thomson, shares expertise on reducing reliance on offsite biodiversity units, enabling developers to contribute effectively to these goals:

  1. Proactive planning

Gregor says that one of the most effective ways to achieve BNG on developments is engaging with an ecologist early on in the planning process. The environmental expert comments: “By conducting ecological assessments early, developers can make informed decisions about site layout, focusing construction in areas of lower biodiversity value while protecting and enhancing more sensitive areas.

Early ecological input should also guide landscape design, adds Gregor, helping developers choose habitat types and species that will thrive long-term and deliver meaningful biodiversity enhancements. For example, a species-rich hedgerow planted with native species will have a better biodiversity value than a non-native hedgerow.

  1. Urban greening

Urban greening is another recommended tactic to reduce the need for offsite biodiversity units. For example trees provide multiple benefits in urban environments. They offer shade to buildings and people, help prevent streets from becoming wind tunnels, and serve as habitats for wildlife, offering roosting, nesting, and feeding resources for insects, birds, and bats. Trees also improve air quality by removing harmful pollutants, absorb water to reduce flood risk, and capture and store carbon, contributing to climate change mitigation.

Gregor comments: “At Thomson we’ve noticed that green and blue spaces are highly valued by homeowners. Blue spaces are defined as those with a prominent water feature or body of water easily accessible by the public, whereas green spaces refer to an abundance of plant life. This shows that developments with green space often see higher property values and healthier communities, making urban greening not just an ecological necessity but a social and economic priority for developers too.”

  1. Green (and blue) infrastructure

Including green and blue infrastructure in urban planning is becoming increasingly mainstream, according to experts at Thomson. For instance, the Government’s Environmental Improvement Plan sets a goal for everyone to live within a 15-minute walk of a green or blue space. To support this, Natural England has produced publicly accessible resources to identify existing green infrastructure and opportunities for expansion.

BNG can play a key role in funding the creation, management, and monitoring of new green and blue spaces. This funding mechanism is particularly important for cash-strapped local authorities, says Gregor, as BNG offers an opportunity to move away from the uncertainty of government funding towards a more sustainable financial model.

  1. Urban drainage systems

As climate change increases flood risks, BNG strategies can play a key role in managing these threats. Recent storm conditions and dangerous weather have raised UK-wide concerns over potential flood damage, particularly after a 40%³ cut in the amount of flood protection promised by the UK government. Sustainable urban drainage systems (SuDS), designed to reduce surface water runoff, enhance biodiversity, and improve water quality, can also help mitigate flood risk and offer recreational opportunities.

Regions across the UK are at risk of experiencing significant flooding, with the West Midlands experiencing the highest flood risk—4,107 alerts over the last five years⁴. With this in mind, effective flood mitigation strategies are essential. Local authorities and developers can significantly lower the impact of future flood events by investing in critical infrastructure and regulating development in flood-prone areas.

Gregor adds: “As housebuilders and urban planners face increasing pressure to meet Biodiversity Net Gain (BNG) requirements, innovative on-site strategies offer a path forward. Meeting BNG requirements on-site can be challenging, particularly for smaller developments where space is at a premium. However, by optimising layout and landscape design, developers can maximise the biodiversity value of their projects. Through early ecological input, the integration of green infrastructure, and the adoption of nature-based solutions, developers can not only meet regulatory targets but also contribute to a healthier, more resilient urban environment.”

To find out more about Biodiversity Net Gain (BNG), please visit: https://www.thomsonec.com/news/maximising-onsite-biodiversity-ecology-skills-gap/