Biodiversity net gain (BNG) and the built environment

Sophie Harbert

Sophie Harbert

Biodiversity is vital for life on earth. Its abundance creates fertile soils, allows for pollination, and offers us clean water, as well as providing plants for food and medicines. Biodiversity is rapidly declining globally due to human impacts such as deforestation. Economists have predicted that nature is worth around half of the world’s total GDP, and provides $44 trillion of economic value generation. It is therefore vital that all businesses wake up to the value of biodiversity, their impacts on it, and how they can help to preserve it.

What is biodiversity net gain?

Biodiversity net gain (BNG) is a new UK legislation, in effect since 12 February 2024, which is relevant to developers, land managers, and local planning authorities. It now forms a mandatory part of the Environment Act 2021. Biodiversity net gain involves creating and improving natural habitats through developments, ensuring habitats and wildlife are left better off than before they began.

The legal agreement is now to achieve a BNG of 10%, which should result in the long-term creation of projects in the UK that positively benefit biodiversity, resulting in cleaner air, new plant and animal habitats, and more green spaces for people to enjoy.

Who are BNG rules relevant to?

The new rules around biodiversity net gain are relevant to:

  • developers of major developments
  • developers of small sites from 2 April 2024   
  • developers of nationally significant infrastructure projects from late November 2025  
  • land managers wanting to sell in the BNG market
  • local planning authorities (LPAs)

Some developments will be exempt from BNG rules including existing planning applications, smaller householder applications, and (controversially) those relating to the high-speed rail network expansion of HS2.

A key part of an environmental sustainability assessment for the construction sector

The built environment sector has a large environmental impact and is thought to be responsible for 30% of global biodiversity loss. The impacts of the construction industry are especially seen in the creation of concrete, which is the highest consumed product on earth (besides water), responsible for over 4 billion tonnes of carbon dioxide emissions annually.

However, it is important to note that the construction industry is largely beneficial to society, creating housing and facilities such as hospitals. The aim is to achieve social value from projects with as little negative impact on the planet as possible. Projects should therefore conduct rigorous environmental sustainability assessments which consider ways to benefit nature—in other words, not sacrificing plant and animal habitats for the creation of our own.

It is important that reporting for BNG is done alongside consultations with an ecologist who can accurately measure the biodiversity value of the existing habitat, using the statutory metric, and advise on suitable changes to the land. Landowners are responsible for monitoring and achieving the desired changes for at least 30 years. As a last resort, if developers cannot achieve BNG, they must buy credits from the government which contribute to habitat creation in England.

Contribution to business sustainability strategies

It is heartening to see this mandatory reporting and tracking of biodiversity, as it has traditionally been an overlooked area. CSRD also has a chapter on biodiversity and ecosystem reporting, reflecting how policymakers and organisations are waking up to how biodiversity is essential for business continuity and fundamental to life on Earth. We look forward to witnessing the positive implications of the BNG legislation: benefiting the environment, green infrastructure, and job growth.

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