The No. 1 mistake in BNG reports
Are you an ecologist or planning consultant working on the metric for a Biodiversity Net Gain project? Find out below the No.1 mistake in Biodiversity Net Gain (BNG) reports, according to GNCF.
What is the No.1 mistake in BNG reports?
Our answer: not taking into account the BNG trading rules.
On top of the intensity of survey season, and a thousand different bits of planning policy to work out, there’s now the complex beast of Biodiversity Net Gain metric to wrestle and report on.
Our top tip before making any recommendation on the number of offsite BNG units required for a site, is to have second look at the BNG trading rules. (See Table 3, p.13).
Nearly all of the ecology reports passed by GNCF don’t take into account the trading rule, ‘low distinctiveness habitats cannot compensate for the loss of medium/high distinctiveness habitats’. This means that the number of offsite units required by legislation are being underestimated in the client’s report.
Compensating for loss of medium/high distinctiveness
The trading rules may mean that the total number of biodiversity units that are created for a development site (offsite and onsite) may end up being a higher number of units than the baseline +10%, so that not only is the 10% rule met, the trading rules are also met 😶.
This is because a site may have included more onsite biodiversity units of low distinctiveness than there were originally, but has not been unable to compensate for the medium/high distinctiveness units lost onsite. These medium/high units, as per the trading rules, will have to be re-created offsite.
What does this look like in practice?
In this example the ecologist’s report recommended 1.20 offsite units, but with trading rules observed the total required is 1.38 units.
“Gloucestershire Nature + Climate Fund (GNCF) has reviewed the DEFRA BNG statutory metric provided for your development. To achieve a 10% uplift on this site requires 1.20 additional units as the baseline is 1.46units (plus 10% net gain = 1.606 units) and the net loss of habitat to the site is -1.05 units. However, looking at the type of habitat lost from the site we can see that 1.38 units of medium habitat distinctiveness will be lost which, according to the trading rules, cannot be compensated for by the proposed habitats of low distinctiveness (also see screen shots from the metric). So while the requirement for 10% BNG can be met by 1.20 additional units, to also meet the trading rules, the site requires 1.38 units of the right medium distinctiveness habitat, or any habitat type of high distinctiveness.”
When using the statutory metric for area habitats – we can’t rely on the answer in the ‘unit deficit’ cell from the bottom of the ‘headline results’ tab in the metric; we also have to check the ‘Trading Summary Area Habitats’ tab and the ‘Unit shortfall calculations’ tab. If there are orange error highlights in the ‘medium/high/very high’ tables of the ‘Trading Summary Area Habitats’ tab, it means that the trading rules will need to be taken into account.
We can help!
Do get in touch if you’d like GNCF to help interpret your biodiversity metric:
rachel@glosncf.com