Despite several false starts and delays, Biodiversity Net Gain (BNG) is nearly upon us. What does this mean in practice – well, firstly, be prepared for a lot of confusion as Local Authorities seek to understand the deluge of information on this and begin to apply it. Even the main government guidance is, at the time of writing, only in ‘draft’. But, sitting as we are upon the crest of a wave, waiting for it to take effect from next week, we seek to break it down for you in the following article and provide you with some useful resources as well as a practical overview of the key points as they stand at present.
The legislation
The legislation was published by the Government on 29 November 2023. As such, in England BNG is becoming mandatory under Schedule 7A of the TCPA 1990 (as inserted by Schedule 14 of the Environment Act 2021).
Then there is the secondary legislation that is needed in order to enact the above. The Biodiversity Gain (Town and Country Planning) (Modifications and Amendments) (England) Regulations 2024 will come into force on the 12th February and extend to England and Wales. These regulations will modify and amend: Part 2 of Schedule 7A to the 1990 Act: Development in Phases; The Town and Country Planning (Section 62A Applications) (Procedure and Consequential Amendments) Order 2013; The Town and Country Planning (Development Management Procedure) (England) Order 2015.
The aim of BNG is to create and improve natural habitats. It is an approach to development and/or land management that will result in an increase in or improvements to a natural habitat, compared to what was there before development. Developers must deliver a BNG of 10%.
The timetable
From 12 February 2024, major development (unless otherwise exempt) will have to deliver mandatory BNG. What constitutes major development we hear you cry – well for the purposes of BNG, major development includes: residential development with 10 or more dwellings, or a site area greater than 0.5ha.
Exemptions are listed here and include:
- development below a de minimus threshold [development that does not impact a priority habitat and impacts less than 25sqm of non-priority onsite habitat (e.g. modified grassland) or 5sqm of non-priority onsite linear habitat (e.g. native hedgerow);
- householder development;
- small scale self-build and custom housebuilding (fewer than 10 dwellings, less than 0.5ha).
From 2 April 2024, small sites will need to deliver mandatory BNG. Small sites include: residential development where the number of dwellings is between 1 and 9; or if unknown, then the site area is less than 0.5ha; or commercial development where the floorspace created is less than 1,000 sqm or the total site area is less than 1 ha.
Transitional Arrangements
Mandatory BNG only applies where the planning application was made (i.e. submitted, not determined) on or after 12 February 2024.
If you have received planning permission before 12 February 2024 (and that permission wasn’t subject to BNG), s73 applications to vary conditions will also be exempt from BNG. Similarly, Reserved Matters will not be required to fulfil mandatory BNG if the outline was approved prior to mandatory BNG.
Furthermore, if a planning application for a small site development was made during the extended transition period (12 Feb and 2 April 2024) and a subsequent s73 variation was granted after 2 April 2024, the same transitional arrangements will apply and BNG will not be required on any subsequent s73 variations.
BNG and your planning application
If you don’t meet the exemptions or aren’t subject to a transitional arrangement then your planning application will need to be accompanied by certain information which is set out in The Biodiversity Gain (Town and Country Planning) (Modifications and Amendments) (England) Regulations 2024. See here.
In order to give some overview of the process in action, when you apply to the LPA for planning permission, you will need to confirm whether your development is exempt from BNG.
If it is not exempt, you will need to attach a metric tool calculation showing the site’s biodiversity value before development. You should also provide information about how you intend to meet the BNG requirement, including details of proposed significant on-site enhancements.
You may need a legal agreement. You may also need a habitat management and monitoring plan (HMMP). The terms of these will set out responsibilities for creation and enhancement, and monitoring and reporting.
If the LPA grants planning permission, you will need to create a biodiversity gain plan. This is a document that shows how you will achieve BNG. In your biodiversity gain plan you must provide evidence for your BNG decisions.
You must submit your biodiversity gain plan, including a metric tool calculation that shows how you will meet your mandatory BNG, to the LPA. (See the guidance on the biodiversity metric.) The LPA must approve or refuse your biodiversity gain plan within 8 weeks.
The LPA must approve your biodiversity gain plan before you start development.
If applicable, the 30 years of BNG management and maintenance starts from the time the agreed initial habitat creation or enhancement is completed (for example, after one year of tree planting, pond digging or seeding).
If you do not meet your BNG requirements, you might be in breach of planning conditions, planning obligations or legal agreement, and the LPA could take enforcement action against you.
The statutory biodiversity metric
For the purposes of BNG, biodiversity is measured in standardised biodiversity units. A habitat will contain a number of biodiversity units, depending on things like its: size; quality; location; type.
There is a statutory (official) biodiversity metric, which is a way of measuring:
- how many units a habitat contains before development;
- how many units are needed to replace the units of habitat lost and to achieve 10% BNG.
To prove you have accurately calculated the number of biodiversity units for existing habitat, or habitat enhancements to achieve BNG, you must use the calculator called the statutory biodiversity metric tool.
It is also worth remembering that the emphasis of the 10% is on the whole of the original site and that any remaining site after the additional built form needs to incorporate the whole value of BNG. For example, if the site is 100sqm and you only build on 50sqm, you still need to achieve 10% of 100sqm.
Ways to achieve BNG: on-site units, off-site units and statutory biodiversity credits
There are 3 ways a developer can achieve 10% BNG:
- They can enhance and restore biodiversity on-site (within the red line boundary of a development site);
- If developers can only achieve part of their BNG on-site, they can deliver through a mixture of on-site and off-site. Developers can either make off-site biodiversity gains on their own land outside the development site, or buy off-site biodiversity units on the market;
- If developers cannot achieve on-site or off-site BNG, they must buy statutory biodiversity credits from the government. This must be a last resort. The government will use the revenue to invest in habitat creation in England.
Developers can combine all 3 options, but must follow the steps in order. This order of steps is called the biodiversity gain hierarchy.
10% BNG is required whether or not the development impacts existing biodiversity.
Your net gain must be maintained for a minimum of 30 years if you are making off-site gains, or significant on-site gains. Responsibilities will be set out in a legal agreement (s106 and conservation covenant).
Ideas for types of BNG that doesn’t involve use of land include; Green Roof (there are different types that can have better gains), green walls, planters, window boxes and ponds. Remember that the BNG needs to respond on a like-for-like basis, so if you are losing scrub habitat, then a normal lawn or a tree may not be deemed an acceptable replacement and a meadow area may be more appropriate.
What expertise do I need to prepare an application?
An ecologist should be taken on-board the project team who will measure the biodiversity value of your existing habitat and explore ways to achieve BNG using the metric tool.
If you have a small site, you don’t necessarily need an ecologist. You can either use the simpler small sites biodiversity metric tool yourself, or someone familiar with the site can do a survey and make a calculation. This could be the landscape architect.
Useful links
- Understanding biodiversity net gain – GOV.UK.
- The Biodiversity Gain (Town and Country Planning) (Modifications and Amendments) (England) Regulations 2024
- Environment Act 2021 – Schedule 14
- Biodiversity Net Gain – what are the exemptions? – Environment
- Biodiversity Net Gain FAQs – Frequently Asked Questions | Local Government Association
About us
We are Plainview Planning – a solutions orientated, experienced and knowledgeable team of planning consultants. If you need professional and informed planning support with your development project, then contact our team via enquiries@plainview.co.uk, to see how we can best assist you, providing the site address and a brief overview of your project. We value your privacy and any information which you provide will not be shared outside of our company and will only be used in relation to your enquiry.