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Home / News and Insights / Blogs / Planning Act 2008 / 904: What is biodiversity net gain and will it affect DCOs?

Today’s entry explains what biodiversity net gain (BNG) is and reports on government moves to require nationally significant infrastructure projects to provide BNG, and other green developments.

As a reminder, the Environment Bill, currently going through the House of Lords, will require planning permissions to have a condition committing to biodiversity net gain (see clause 92 and schedule 14). It also extends the duty on public bodies to further the conservation of biodiversity to conservation ‘and enhancement’ (clause 95).

What is biodiversity net gain?

BNG means that the biodiversity value of a site attributable to a development must exceed the site’s pre-development value by at least 10% (for the moment). That can include not just the value of the site itself, but registered offsite biodiversity gain and purchased biodiversity credits. (Developers: phew, we can throw money at the problem). Biodiversity value is calculated by reference to the ‘biodiversity metric’, something the Secretary of State is obliged to publish.

Version 2.0 of a draft metric is already available, with version 3.0 supposedly coming out in ‘Spring 2021’, which is getting a bit of a stretch. The metric is based on dividing land into habitats and giving a score to each, based on its area in hectares multiplied by scores for distinctiveness, condition, strategic location and connectivity, to give a number of ‘biodiversity units’. When calculating the post-development score you must also multiply by three risk factors: difficulty of achieving the improvement, length of time taken and how close any new habitat is to the existing habitat (all which serve to reduce the score). A handy diagram showing all this can be seen on page 15 of this document.

Currently, the bill provides that only town and country planning permissions have to have BNG as a condition, and not development consent orders (DCOs). Arguably the existing duty on public bodies to conserve biodiversity means that the Secretary of State should ensure when granting a DCO that it at least conserves biodiversity (ie no biodiversity net loss) (for reference this duty can be found at section 40 of the little-known Natural Environment and Rural Communities Act 2006).

Will the change to ‘conserve and enhance’ oblige enhancement? It’s not ‘conserve or enhance’ so you might say there should be a non-zero amount of enhancement, but it wouldn’t have to be much.

New developments

It had been the government’s position that DCOs would not yet be required to provide BNG even if planning permissions were. Things changed on Monday, though, when environment minister Lord (Zac) Goldsmith said in the House of Lords:

‘On biodiversity net gain, I can tell my noble friends Lord Randall and Lord Blencathra and the noble Baroness, Lady Bennett — and, I hope, reassure them — that although nationally significant infrastructure projects remain out of the scope of the mandatory requirement for the Bill for the time being, the government are exploring how a biodiversity net gain approach for big infrastructure projects could best be delivered, including what legislative levers could be used to support it. This is something that we are actively working on.’

This was further elaborated upon in answer to a question from Caroline Lucas MP here – to which the minister Rebecca Pow MP said that the government ‘intends to consult further in due course’ on applying BNG to DCOs.

UPDATE 14 June 2021: the government has today committed to amending the Environment Bill to require DCOs to provide biodiversity net gain, as set out in this response to the Dasgupta Review on the Economics of Biodiversity.

So it seems that it won’t be long until DCOs have to provide BNG, whether via the Environment Bill or otherwise.

The Bill has undergone a few amendments as it arrived in the Lords, and one of these is potentially significant: the introduction of two clauses (105 and 106) allowing habitats regulations to be amended – but only if the Secretary of State is satisfied that any amendments do not reduce the level of environmental protection. Note that is a subjective rather than objective test and hence easier to overcome – it may be quite difficult to compare new with old.

There is still no news on the heralded ‘simplification and enhancement’ of strategic environmental assessment and environmental impact assessment, although according to the Queen’s Speech background briefing notes, these would be implemented in the forthcoming Planning Bill rather than the Environment Bill where you might think they would belong.

Quite a lot to keep tabs on, then, but this blog will try to update you on any developments in this important area.

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