Biodiversity net gain guidance on conservation covenants and irreplaceable habitats

Mandatory biodiversity net gain (BNG) requirements are now in effect, meaning that most new planning applications must provide at least 10% BNG. To assist stakeholders the Department for Environment, Food and Rural Affairs (Defra) has begun to issue guidance on related topics:

Conservation covenants

The Environment Act 2021 introduced the concept of “conservation covenants” as a tool for delivering BNG. As discussed here conservation covenants are private, voluntary agreements between a landowner and a “responsible body” where the landowner agrees to do something on its land for a conservation purpose for the public good. It is expected that they will be used as an equivalent to s.106 planning agreements to bind a site to long-term BNG commitments. 

Local authorities have been to apply to the Secretary of State to be designated a “responsible body” since last summer but there has been zero take up to date (Defra recently published guidance setting out the list of designated responsible bodies with only Natural England on the list). However Defra has now published guidance on the criteria for being a responsible body (namely: eligibility financial security, operational capacity and capability, and ongoing suitability).  Hopefully this will trigger engagement by local authorities as conservation covenants could prove to be a useful mechanism for BNG supply but, as it stands, the primary mechanism remains through a s.106 agreement. 

Irreplaceable habitats

There are certain exceptions to the current mandatory BNG requirement, including where development results in the loss of “irreplaceable habitats” given that these habitats are incredibly difficult to replace due to their age, uniqueness, diversity and rarity.  

The Biodiversity Gain Requirements (Irreplaceable Habitat) Regulations 2024 (SI 2024/48) includes a list of these habitats (which includes ancient woodland, coastal sand dunes and lowland fens) and Defra has recently published guidance which sets out how to use the BNG metric calculation where there are irreplaceable habitats. 

Nevertheless, developers should remember that this is not a free pass at development on irreplaceable habitats. The National Planning Policy Framework still applies which dictates that development resulting in the loss or deterioration of irreplaceable habitats would only be granted in exceptional circumstances and where there is a suitable compensation strategy.