Development planning: 10 per cent Biodiversity Net Gain set to increase upfront application costs

In submitting applications for major residential or commercial developments, applicants now have to demonstrate how the scheme will ensure a minimum of 10 per cent net gain in the biodiversity mix of the development site area.

Where this cannot be achieved, applicants will have to justify it and provide a net gain outside the development site, or purchase off-site biodiversity units on the market or biodiversity credits from central government.

For residential schemes, major developments for these new Biodiversity Net Gain (BNG) purposes are defined as 10 or more dwellings or a site of 0.5 hectares or above where the number of dwellings is not stipulated.

If a building or buildings create 1,000 sq m of floor space or more, or if the site has an area of one or more hectares – for example a commercial development – this will also require the minimum 10 per cent BNG to be demonstrated.

There are some exemptions to the new BNG rules – for example, householder development and self-build or custom-build development of no more than nine dwellings.

The level of detail now required to demonstrate BNG goes well beyond that supplied in a Preliminary Ecology Appraisal (PEA) which still accompanies development applications.

Previously, a full landscaping scheme would have been a matter for a post-application planning condition. However, this is now required as part of the application because it is the only way to calculate the biodiversity points created by new habitat and, thereby, demonstrate the required net gain has been achieved.

Eddisons’ concern is that detailed work to meet the new 10 per cent BNG requirement through demonstrating landscaping & ecology outputs at the application stage significantly adds to the upfront costs of an application.

While biodiversity net gain has been required prior to the recent changes, there wasn’t a legal 10 per cent requirement in force across England. Leaving this work until permission had been granted, previously, meant that applicants could manage the financial risk in avoiding cost if their application was not approved as submitted.

If the application is withdrawn or refused, or if any change to the scheme is required through the normal process of negotiation and amendment, then there are further costs to meet the new 10 per cent BNG requirement.

The alteration to the timing of the requirement for this information adds to the risk. While compliance is costly, failure to do so will only ramp-up costs and delay the delivery of schemes.

Planning professionals will always advise potential applicants to seek expert advice at the earliest possible stage in considering development – these latest BNG requirements only serve to reinforce the wisdom of this advice. And from 2nd April, BNG requirements have rolled out to be a requirement for non-major planning applications, too, unless exempt or below a set threshold. Further biodiversity net gain guidance is likely from central government as it rolls out in practice.

The 10 per cent BNG requirement was just one of the first significant changes this year to have an impact on development interests. It was closely followed, in March, by amendments to the Class MA, General Permitted Development Order – known as ‘Class MA’, for short.

Class MA sees amendments regarding the change of use from Class E – commercial, business & service – to Class C; residential dwellings use. Of course, not all commercial buildings will meet the permitted development criteria. Both BNG & Class MA changes are significant and throw up new challenges for developers and local planning authorities alike.