Further to the consultation paper published last December, revised guidance published on 21st July confirmed that net gain in planning “describes an approach to development that leaves the natural environment in a measurably better state than it was beforehand. Net gain is an umbrella term for both biodiversity net gain and wider environmental net gain.”The document provides guidance as to how planning authorities can encourage net gains for biodiversity through planning policies and decisions. It also confirms that planning conditions or obligations can, in appropriate circumstances, be used to require that a planning permission provides for works that will measurably increase biodiversity. Unilateral undertakings can also be used as a way in which biodiversity net gain can be achieved.
The revised document also provides additional detail on ways development can enhance biodiversity and the environment – such as drainage areas to create wetlands for birds and amphibians. It also points out that measures can involve the creation of new habitats, enhancement of existing habitats, provision of green walls and roofs, street trees or SUDs. It confirms “Relatively small features can often achieve important benefits for wildlife, such as incorporating ‘swift bricks’ and bat boxes in developments and providing safe routes for hedgehogs between different areas of habitat.”
The guidance also confirms that benefits could be achieved entirely on-site or by using off-site measures such as “habitat banks” – areas of enhanced or new habitats which generate biodiversity.
It is evident from the guidance that planning authorities need to ensure that any evidence supplied by the applicants in support of their applications are supported by the appropriate scientific expertise and local wildlife knowledge
Elsewhere, the guidance says that biodiversity net gain “does not override the protection for designated sites, protected or priority species and irreplaceable or priority habitats” set out in the National Planning Policy Framework