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Top 12 questions planners ask about Biodiversity Net Gain (BNG) in relation to planning applications


After collaborating with The Planner to showcase a webinar for Local Planning Authorities on how to make BNG work in your area, we have compiled the top 12 questions that we were asked about Biodiversity Net Gain (BNG). To download all 56 questions and answers, please fill in this form.



1. How is it proposed that you would create a model that produces zero risk from judicial review?

If LPAs engage in setting up their own sites that are not independent of their planning function (significant conflicts of interest exist) then there is a significant risk of legal challenge from 3 party objectors to a planning decision. This risk is negated if LPAs require developers to use Habitat Banks outside the LPAs control. It separates their regulatory function of the planning system from BNG delivery. With our Habitat Banks, Environment Bank takes all the risk of delivery and the planning permission decision is independent of any material benefit accruing to the LPA.


2. If a site is already habitat rich, can it qualify as a Habitat Bank? Is it acceptable to merely retain the condition of a site or must it be ‘improved’ in some way? What about sites that are naturally increasing year on year anyway with minimal management, such as woodland, and in which a 30-year timeframe is actually quite negligible?

The site has to be improved; one cannot simply draw a line around an existing site of some significance and ‘protect’ it. For the economics to work, it is important to generate as much uplift as possible (which generates more credits per hectare). That is how we will deliver nature recovery, rather than protecting already good sites (which should/are already being protected through the planning system via environmental policies within the local plan).


3. Can a local planning authority direct that the BNG be in their geographic area only as a condition of consent?

We do not think that the LPA can say that it has to be in their specific geographic area because some local authority areas are very constrained in terms of providing an off-site area. The metric deals with this by increasing the credit requirement for off-site areas provided at some distance from the development impact.


4. How is it proposed to provide a legal framework for delivery of sites?

Environment Bank has invested considerably in creating a) the Habitat Bank Agreement which includes the Habitat Management Plan, working with the landowner and which the landowner signs, and b) the BNG Credit Purchase Agreement with the developer which is used to provide the evidence needed to discharge the S106 agreement with the LPA. These are robust legal documents.


5. By pushing all or most of BNG offsite, is there a risk of creating ‘ecological deserts’ in and around developments, which would further disconnect people from nature and harm wellbeing? Don’t Habitat Banks just allow developers to exacerbate these problems by maximising the ‘quantum’ of development while passing the biodiversity issue onto someone else to deal with?

No, the developers will always want to e.g. sell houses and so excellent landscaping and planting, which is placemaking, is really important. However, this is not biodiversity. There is much evidence now that on-site delivery of BNG has minimal value to biodiversity because they will always be small, fragmented areas and are usually untidy (think woodland scrub and tall grassland mosaics) and where these have been tried the residents’ association usually manicures them back to amenity grassland or similar. Nor is on-site BNG consistent with the Lawton principles of bigger, better and joined. Providing great placemaking and biodiversity are often very different things. And large commercial warehousing, logistics parks and similar, have very limited space for even great landscaping unless they acquire additional land, which is very unlikely. So, such developments will always need a better solution – as provided by large scale Habitat Banks.


6. How can onsite BNG be managed over the 30-year period? David suggested that management companies/community trusts are not the best answer - what is the evidence for this? At least one local authority (Tunbridge Wells) is using “legally binding Landscape and Ecological Management Plans” which “have the benefit of being in perpetuity”. Is this a good solution?

There is no reason why on-site cannot be delivered as long as a) there is a robust, effective management plan in place, b) the developer has set aside the 30 years of funding for on-site c) that the developer also funds the 30 years of monitoring and reporting. There would also need to be in place a mechanism and funding to intervene in on-site BNG areas if the habitat is not performing in accordance with the objectives of management that underpins the efficacy of the biodiversity gain plan and on which the development was permitted. If all of these things are in place there is every reason to be confident that the BNG on-site will be delivered. However, in our experience and that of the ecological community and recent research, this very rarely happens.


7. Will the Habitat Bank sites require a change of use planning application in the way SANG sites do?

Potentially but only for wetland. All the other habitat types require farming, eg: cattle or sheep grazing and woodland management/hay cutting so stay within the realms of agriculture use.


8. Doesn't this bypass the purpose of the Env Act 2021 - and bypass the required mitigation hierarchy - which requires onsite mitigation. (Off site mitigation must only be a last resort).

No. Although it is stated that off-site is a last resort, the current thinking has moved to a position where the best delivery will be off-site as on-site usually fails. There has been a conflagration of objectives confused by reference to ‘people need nature’, health and well-being, greenspace provision. Clearly these are important but the BNG initiative is to protect, enhance and restore biodiversity. The other potential benefits are ancillary to the main purpose. And indeed some are mutually exclusive eg areas disturbed within a housing scheme by residents actually reduces the potential for biodiversity.


9. How is the number of available credits determined per Habitat Bank?

By applying the Defra 3.1 metric to ascertain the biodiversity units present on the land parcel subject to a Habitat Bank, then to develop a plan of habitat creation for a range of habitat types and reapply the metric to the fully functioning site. The uplift in units translates directly to credits available for each land parcel. Credits therefore available differ depending on the starting position of the land and the ultimate type of habitat to be created.


10. Is there a geographical limit on offsite purchase of credit? ie: Would a developer have to purchase credits in a Habitat Bank in the same local planning authority as my development proposal?

In general yes, but if a site is not available (for example many London boroughs are constrained in terms of land availability) then the metric allows for credits to be purchased from further afield. In practice it is highly likely that credits will be purchasable within 25km of the site of a development, and largely closer than this as the market for provision increases.


11. How will it be ensured that developers do not clear sites prior to an application / survey being done so that the units on the site are lower, and therefore the uplift is smaller?

The baseline against which changes are assessed has been set to January 2020. If a consultant supported a developer in clearing a site prior to the production of an EIA they could be charged with professional misconduct. The developer would also likely be fined.


12. If the BNG fails for any reason over the 30 years, as this is a legal requirement and the development has been delivered conditional on this requirement, who is liable and what is the effect on the permission?

In the case of our Habitat Banks, Environment Bank accepts the liability for delivery and the condition is discharged by the developer once the credits are purchased. In relation to on-site provision, it will be a requirement that the developer provides a fund for the 30 years of management which is independent of them.

To download all 56 questions and answers, please fill in this form.
56 things planners need to know about BNG

After collaborating with The Planner to showcase a webinar for Local Planning Authorities on how to make BNG work in your area, we have compiled 56 questions and answers that we received from the webinar to equip you with all the info you need. 

About the author

David Hill