BNG Calculator
Enter your offsite requirement and see what BNG units cost from our habitat banks across England. Reserve online with a £150 deposit.
How the Calculator Works
1. Enter Your Requirement
Enter the offsite units your ecologist's metric says you need, by habitat [, and tell us where your development is]. [Or upload your metric and we read the requirement for you.]
2. Choose a Habitat Bank and See Your Price
Pick a habitat bank and see the price per unit for each habitat. The calculator shows the units you need, the price per unit and the total. [We apply the spatial risk multiplier for you.]
3. Reserve Your Units
Pay a £150 deposit to hold your units for 30 days, then sign the contract online. We send your document pack within one to two days of signing.
What You Need Before You Start
Your ecologist completes the statutory biodiversity metric, and your Biodiversity Gain Plan relies on it. The calculator starts from the offsite requirement that metric gives you. You will need:
The offsite units required, split into area, hedgerow and watercourse units. Each type is calculated separately, and units cannot be swapped between types.
The type and distinctiveness of the habitat you are replacing. Offsite units must match or exceed both.
The local planning authority your development sits in.
The statutory biodiversity metric is free from GOV.UK. If you do not have an ecologist yet, we can recommend one.
How Distance Changes the Number of Units
Offsite units are worth less the further they are from your development. The government calls this the spatial risk multiplier.
Same area as your development: multiplier 1. Buy 1 unit for every unit you need.
Neighbouring area: multiplier 0.75. Buy 1.33 units for every unit you need.
Elsewhere in England: multiplier 0.5. Buy 2 units for every unit you need.
If your metric shows 10 units, a scheme in a neighbouring area means buying 13.33 units (10 ÷ 0.75). A scheme elsewhere in England means buying 20 (10 ÷ 0.5).
Area means your local planning authority or National Character Area. Buying close to your site is nearly always cheaper as well as better for local nature.
Why Greenshank?
See the price per unit before you reserve.
Every unit is secured by a Section 106 agreement or conservation covenant, with no ongoing liability for you.
30 habitat banks across England, with 96% coverage of LNRS areas.
If you find a lower like-for-like quote, we'll beat it or give you £100.
BNG Calculator FAQs
Two things share the name. The statutory biodiversity metric is the government's calculation tool. Your ecologist uses it to measure the biodiversity value of your site before and after development and to work out how many units you need. Our calculator takes that requirement and prices it using units from our habitat banks.
The government requires a competent person to complete the statutory metric, and most developers use a professional ecologist. The small sites metric, which suits some smaller developments, does not require one.
That depends on the habitat you lose, the habitat you keep or create on site, and how far the units are from your development. Your metric gives you the number. Every unit you deliver on site is one you do not need to buy offsite.
Prices vary by habitat type, distinctiveness and scheme, and with availability and demand. The calculator shows the price per unit for each scheme before you reserve.
Yes. Fractional units are available from all of our schemes.
Yes. Our Advanced Assurance service checks that your proposed purchase meets the trading rules and is cost-effective. It costs £250. [Confirm this is still offered.]
Most developments that need planning permission in England do. Householder applications, sites of 0.2 hectares or less that do not affect a priority habitat (for applications made from 6 August 2026) and some other developments are exempt. Check the government's exemptions guidance or ask your planning consultant.
The calculator prices units for developers. If you own land and want to know what it could earn, see our guide to BNG for landowners.
Ready to Price Your Units?
Enter your requirement, see your price and reserve online.