A mandatory 10% biodiversity net gain (BNG) will be required on most new developments from autumn 2023. But an increasing number of Local Plans already require BNG, as our research on 322 English local planning authorities (LPAs) has found.
Currently, only 5% of these LPAs have an adopted a BNG policy, but 23% have emerging policies. The relative proactivity of some regions indicates where interest is strong and where developers should refine their strategies.
In the West Midlands, 53% of LPAs have a BNG policy either adopted in Local Plans or emerging, and the South East is also ahead of the national average at 32%.
The research shows a higher uptake among LPAs that have declared a climate emergency, and also among those that turn over a high number of planning decisions. Some 42% of LPAs that make 70 or more major planning decisions annually have an adopted or emerging BNG policy, compared with only 22% of those that made zero to 39 major planning decisions.
In those areas with policies, developers are already making the choice of offsite or onsite BNG schemes. While onsite is the government’s stated preference, offsite can be financially beneficial as a high proportion of onsite green space reduces density, adversely affecting development value and viability.
Selecting land for offsite solutions will be guided by the ‘spatial risk’ multiplier within Biodiversity Metric 3.1, which awards a higher score to land within closer proximity. But offsetting far from the development site is sometimes unavoidable.
Urban areas naturally have a lack of suitable land: in Birmingham, residential gardens account for more than 28% of the total land use and almost half of undeveloped land; only 6.33% of Birmingham’s land is agricultural and 3.18% is forestry or woodland, providing few opportunities for offsetting.
Carter Jonas’s research provides granular data to help inform this new and complex decision-making, which is already occurring in LPAs across the country.
Kieron Gregson is an associate partner at consultancy firm Carter Jonas (London)