BNG will be introduced in phases with small sites having until April 2024 to comply with the regulations. Small sites are defined as those with one to nine inclusive dwellings on a site less than one hectare in area or with a site area of less than 0.5 hectares where the number of dwellings is not known. The government has made exemptions for self-build homes and householder applications to ensure that implementation is targeted towards developments with the most significant impact.To ensure compliance with BNG, local planning authorities with planning oversight will receive £16 million in funding. This funding will be used to expand resources and upskill teams, including ecologists, to increase their capacity to oversee, and enforce, the new legislation.
How is BNG measured?
This is the million dollar question. Defra has developed a metric for calculating BNG and the calculation involves a comparison between the “baseline” biodiversity value of the site (which has been arbitrarily chosen as being the biodiversity value of the site pre-development) and the anticipated post-development biodiversity value. The baseline can be measured from a point in time some years in advance from the present to avoid any incentive to degrade the site’s existing biodiversity level.
The measurement of biodiversity value at each stage will take into consideration the distinctiveness, condition and strategic significance of three types of “biodiversity units”. BNG must be maintained for a minimum of 30 years post-completion.
How can BNG be achieved?
On-site solutions may come in the form of green walls, brown roof space or blue infrastructure such as wetlands and ponds. Developers will also have the option of tapping into habitat banks to secure gains from the start.
Where on site gains will not be sufficient, the legislation allows for off-site mitigation. This could bring opportunities to private landowners who will be able to capitalise on the new legislation through the “off-site unit market.” Natural England will publish a national register of biodiversity units on which landowners (and local authorities) can list land they have enhanced for developers to purchase or let. This market will also provide an opportunity for developers to monetise any excess of BNG beyond the 10% target.
Whilst this market establishes, the government will be offering a statutory biodiversity credits scheme. Where developers cannot achieve BNG gains either on or off-site, these credits could provide a last resort.
Article by Tori Madine - buildings specialist at clean tech marketing experts Content Coms.