What biodiversity net gain requires of you

Biodiversity net gain became mandatory for most development in England in February 2024. The principle is simple enough: a development has to leave biodiversity measurably better off than it found it, by at least 10%, some councils require higher improvements.

The complications are all in the detail.

The measurement

Biodiversity is measured in units using the statutory biodiversity metric. The metric scores habitat on its type, its distinctiveness, its condition and its strategic significance, and produces a unit figure for the site before development and a target figure for after.

Area habitats, hedgerows and watercourses are scored separately, and cannot be substituted for one another. If your site loses hedgerow, you need hedgerow units. Area units will not do. There are numerous rules that apply to biodiversity net gain units, these trading rules are complicated and have a lot of quirks! We can cut through the noise and get you to the information that you need to make good decisions onsite and offsite.

The hierarchy

The expectation is that achieving the gain should be explored on the development site first. Where that is not possible, it can be delivered off site, either on land the developer controls or by buying units from someone like us. Statutory credits from the government exist as a last resort, they are expensive and will not be used in the vast majority of cases.

The 30 years

Whatever route is taken, the habitat has to be secured and managed for at least 30 years. That is done through a section 106 agreement with the local authority or a conservation covenant with a responsible body.

It is not a one-off cost at planning stage but a three-decade commitment to manage, monitor and report on habitat, which is why buying units from a habitat bank is attractive: the obligation sits with the bank instead of with you. If you choose to create a habitat bank on site then you will need to comply with the management plan over thirty years and care for the habitat accordingly. Penalties will apply if you do not. If you purchase your units offsite that responsibility lies entirely with the land owner.

When to think about it

Earlier is always better, particularly if you have a large development. The unit requirement depends on what habitat your site currently holds, surveying must be done by an ecologist at an appropriate time of year. Most surveys are done in Spring & Summer. Once the baseline is established it can be assessed to understand which habitats are the most valuable, protect those on site and you can save significant amounts of money later on.

If you want to know what your requirement might cost, send us the site details and we will tell you.