Quick Fire Biodiversity Net Gain Q&A

Your top biodiversity net gain FAQs and our simple, straightforward answers

When will net gain become law?

It is expected that the Environment Bill will pass into law after the summer Parliament recess, in late summer or autumn 2021.

What is a biodiversity unit?

There are two types of biodiversity unit. The BNG metric calculation can be computed for both habitat units and hedgerow units, to account for gains and losses in the same at your site.

A unit is a minimum functional area of habitat (e.g. woodland) or hedgerow that qualifies through the metric calculation as one complete unit. There is no direct correlation with area in absolute terms, as some sites are naturally more biodiverse than others. Generally, though, the more biodiverse the site then the smaller the area that constitutes a single unit.

If BNG isn’t law already, why are my local planning authority asking for it now?

Cornwall, Wiltshire, Dorset, Leeds, Bristol City, Lichfield, Warwickshire County all have their own local level policies and methods that relate to BNG directly or at least, no net loss. In Cornwall’s case since 2020 all major applications have had to provide 10% net gain, and in Warwickshire’s case they have their own metric.

The point is, it’s coming, so some councils have taken the view that it’s better to be over prepared than fail on delivery on day one. Many pilot projects have already bene undertaken or are underway to avoid “day one failure to deliver” once BNG becomes law.

Why 10%?

Following a consultation in 2019, it was decided that 10% would be the mandatory minimum. It is clearly arbitrary, and many experts believe that it may be adjusted in future.

What are the BNG exemptions?

To date nothing is dyed-in-the-wool, so to speak, although it is widely anticipated that householder applications (permitted development, extensions and renovations for example), and some type of brownfield sites will all be exempt from mandatory net gain.

Why are there so many metrics?

Right now, various authorities are experimenting with their own but in May-June of 2021, Metric 3.0 will be released by DEFRA, along with a “small sites” version.

The Environment Bill will probably define the variance allowed in the application of metrics that are not directly originated from the Department for Environment.

What does the BNG condition assessment consist of?

It is very similar to a preliminary ecological appraisal, only it employs the DEFRA metric methodology to produce a calculation for biodiversity units, as well as the standard assessment of habitats and legally protected species that are relevant planning considerations in their own right.

How much should I expect to pay for a BNG assessment?

For an average development site, the upfront ecological survey which is used to inform the scheme might cost something like £500 to £1,000 (ex VAT) from an ecologist, depending upon the scale and uniqueness of your site, and the quantity and importance of nearby ecological receptors.

How much does a biodiversity net gain plan cost?

For the landowner, and off-site biodiversity management plan is typically around £1,000 (ex VAT), again depending upon the number of units needed to be achieved, the complexity of your scheme and proximate habitats that require connectivity.

For the developer, an on-site net gain plan is typically from £500 to £1,000 (ex VAT). Again, this can vary depending upon the size and intricacy of your scheme, as ell as the number of units you need to achieve a net gain of 10%.

How long does it take to produce a biodiversity net gain plan?

Not long at all. It takes one of our ecologists a matter of days, usually.

How much do the legal fees cost associated with biodiversity net gain?

Recognition of units from the local authority can cost anywhere from a few hundred pounds to thousands, depending upon how much land is being offered and how many biodiversity units are created.

The legal agreement to covenant the landowner to 10% biodiversity net gain over 30 years might cost something like £10,000 including a contribution to the local authority’s legal fees (and the possibly the developer’s).