Guide
BNG units and statutory credits: how the fallback hierarchy prices out
Updated
The unit is the currency of BNG. Where you buy it determines what it costs, and the government's published credit price sets the ceiling on the whole conversation.
The three routes, in order
- 1. On site
- Create or enhance habitat within the development. Normally the cheapest units available, because you already own the land, but it competes directly with developable area and carries a minimum 30 year management obligation.
- 2. Off site
- Deliver gains on other land you control, or buy units from a habitat bank or landowner. gov.uk notes that from 6 August 2026 small (minor) developments not already exempt can consider options 1 and 2 at the same time.
- 3. Statutory credits
- Buy credits from the government. gov.uk describes this as a last resort. Prices are published, and gov.uk states you must buy 2 statutory credits for every 1 biodiversity unit you need to compensate for. gov.uk also states VAT will not be charged on BNG credits.
Why the published credit price matters even if you never buy one
Private off-site unit prices are not officially published and vary by habitat type, location and the seller. The statutory credit price is published, and because credits are always available, it functions as a practical ceiling: no rational buyer pays more for a private unit than the statutory route would cost, allowing for the 2-for-1 rule and the differences between them. That makes the published price table the most useful single reference point when you are handed an off-site quotation.
What the tiers tell you about your site
The tier structure prices habitat by how hard it is to recreate. Low distinctiveness habitats sit in the cheapest tier; lakes and watercourses sit at the top by a wide margin. The practical consequence is that what you have on site before you start is the largest single determinant of your BNG cost. A site of arable or amenity grassland and a site with a watercourse and unimproved grassland of the same area are not comparable schemes, however similar the planning application looks.
Sensible sequence for a developer
- Get a baseline metric calculation before the layout is fixed. This is the only point at which the number is genuinely cheap to change.
- Test layout variants against the metric. Retaining a hedgerow or a mature tree line often costs less developable area than replacing the units it represents.
- Price on-site delivery honestly, including 30 years of management and monitoring, not just the planting.
- Then test the off-site market, benchmarked against the published statutory credit prices and the 2-for-1 rule.
- Keep credits as the fallback they are described as, and use their published price to negotiate rather than as a plan.
Credit prices are as published on gov.uk at the date shown on this page. Check the gov.uk page for current prices before relying on them, and take advice on how the trading rules and spatial considerations apply to your site.