Frequently Asked Questions
Need Help?
FAQs
What is Biodiversity Net Gain (BNG)?
It is a conservation strategy that aims to improve the environment at sites where development projects are constructed.
Developers need to deliver a minimum 10% extra quantity/quality natural habitat than existing, but some councils may require a higher figure of 20% (e.g. Guildford, Elmbridge, etc.).
Since February 2024, it has been mandatory for constructors in the UK to ensure that measurable biodiversity improves on their project sites. That means the environment where the development takes place has to be in better shape, with more or better quality habitats, than before construction started.
What legislation exists concerning biodiversity net gain?
Legislation relevant to the statutory framework for biodiversity net gain in England is set out chiefly in the Town and Country Planning Act 1990, more specifically in section 90A and schedule 7A (Biodiversity Gain in England).
The above provisions were added to the Act by virtue of schedule 14 of the Environment Act 2021.
Why is biodiversity net gain important for planning?
For developments to be sustainable, they should enhance rather than degrade their natural surroundings and contribute positively to the environment, which is what net gain aims to achieve.
How does a property developer accomplish biodiversity net gain?
There are three principal methods that can be used to achieve biodiversity net gain:
- Creating it on-site (within the red-line boundary of a development site);
- If the develop can only do this partially, then adopt a mixture of on-site and off-site gains by purchasing biodiversity units to make up for the shortfall. In other words, developers can make off-site biodiversity gains on their land outside the development site and/or buy off-site biodiversity units on the market.
- If the above is not entirely feasible, developers buy statutory biodiversity credits from the UK government as a last resort. The government uses the revenue to invest in habitat creation in England.
Can BNG be achieved off-site?
Yes, developers can achieve BNG off-site through either enhancement of biodiversity in the vicinity of the development or by purchasing biodiversity units from Habitat Banks.
What are biodiversity units and credits?
Biodiversity units are a way for developers to meet their net gain obligations if they can’t enhance biodiversity on-site completely. So, to make up for the difference, they purchase biodiversity units off-site but in the local area. Biodiversity credits, on the other hand, function much like biodiversity units except that they are obtained from the government.
What is a conservation covenant?
A conservation covenant is a legally binding agreement ensuring that the developer will maintain biodiversity enhancement gains for at least 30 years.
How long must the developer maintain the biodiversity gains?
Biodiversity gains must be maintained for at least 30 years, a minimum time period specified in a conservation covenant.
What is a biodiversity gain plan?
A biodiversity gain plan describes how the development will enhance the site’s biodiversity by at least 10%
What is the method for calculating biodiversity net gain?
The amount of biodiversity units required to achieve BNG is calculated using the Government’s official biodiversity metric tool: Click Here
Then, a biodiversity gain plan must be prepared (incl. map). This gain plan must state where habitat improvement will take place and whether a new habitat must be created to achieve BNG.
What is the Biodiversity Gain Hierarchy?
Developers are encouraged to follow a sequential priority order when trying to achieve BNG. This order of priority is called the Biodiversity Gain Hierarchy. Following this hierarchy means undertaking the following actions:
- Avoid adverse effects from the development on existing on-site habitats (with a distinctiveness score of 6 or higher).
- Mitigate any effects on those habitats that can’t be avoided.
- Improve, or enhance, the existing on-site habitats.
- Create new habitats on on-site areas where enhancement can’t take place.
- Make available off-site registered habitats where such enhancement can’t take place.
- Purchase biodiversity credits if none of the above options are feasible.
How do I incorporate biodiversity net gain into my planning application?
If a development would require a biodiversity gain condition, then the application must be accompanied by certain information, which is laid out in Article 7 of The Town and Country Planning (Development Management Procedure) (England) Order 2015. This information is required in what is called a Biodiversity Statement. The Statement includes the following items:
- First, it states whether the applicant thinks that the permission being sought would be subject to the biodiversity gain condition.
- Second, it provides the pre-development biodiversity value of the site’s habitat, giving the date of the valuation and the methods by which it was arrived at using the metric tool.
- If the applicant wants to use a valuation from before the date of application, that is, an earlier date, then it must also give the reasons for choosing that earlier date.
- Third, the applicant must account for any “degradation.” If the habitat on which the application relates to is somehow degraded, then the Statement must show how that was done and the value is to be taken before project activities were carried out.
- Description of any irreplaceable habitat description (as set out in column 1 of the Schedule to the Biodiversity Gain Requirements (Irreplaceable Habitat) Regulations [2024]) on the land to which the application relates that exists on the date of application (or an earlier date).
A plan drawn to a scale with North direction, showing on-site the habitat existing on the date of application (or an earlier date), including any existing irreplaceable habitat.
#
The statutory framework for achieving biodiversity net gain requires that a Biodiversity Gain Plan must first be submitted to and then approved by the planning authority before the development project starts.
The Biodiversity Gain Plan needs to show how at least 10% biodiversity gain will be met and it needs to be submitted no earlier than the day after planning permission gets granted to discharge the planning condition.
What happens with BNG after planning approval?
The statutory framework for achieving biodiversity net gain requires that a Biodiversity Gain Plan must first be submitted to and then approved by the planning authority before the development project starts.
The Biodiversity Gain Plan needs to show how at least 10% biodiversity gain will be met and it needs to be submitted no earlier than the day after planning permission gets granted to discharge the planning condition.
What is the Habitat Management and Monitoring Plan (HMMP)?
The HMMP describes how the habitat will be maintained and monitored in respect of on-site enhancements or off-site gains. Your plan should include when and how you will:
- plan to deal with the off-site gains or significant on-site enhancements, considering any legal restrictions and requirements
- monitor the habitats, which is different for different habitat types
- report monitoring results
- review management proposals
- change any approach to achieve biodiversity outcome
What is the Habitat Management and Monitoring Plan (HMMP)?
The HMMP describes how the habitat will be maintained and monitored in respect of on-site enhancements or off-site gains. Your plan should include when and how you will:
- plan to deal with the off-site gains or significant on-site enhancements, considering any legal restrictions and requirements
- monitor the habitats, which is different for different habitat types
- report monitoring results
- review management proposals
- change any approach to achieve biodiversity outcome
What if I can not achieve biodiversity net gain on-site?
If it becomes evident that biodiversity gains can not be achieved on-site, both public and private developers might have to consider options that extend the reach of their projects.
That could mean working with land off the beaten path to boost biodiversity, or, if biodiversity net gain can not be fully met, buying statutory biodiversity credits to pay for off-site enhancements.
Those government credits are tended to by the to the Department for Environment, Food, and Rural Affairs (DEFRA)—the government agency that oversees biodiversity credits in England.
What is Habitat Banking?
Here, you would pay a landowner to increase the biodiversity of their land and that uplift is sold as a unit to you in advance. The approach is known as “habitat banking”.
You can create the habitat in advance of the units being sold to you, which will speed up the building project.
However, you would have to exhaust all options on site prior to alternatives. Only then would you look to buy credits within the same priority landscape (local) area.
Is there finance for BNG?
There is green finance, which may even provide some return.
What are the different Biodiversity Unit/Credit Scores?
If you can not buy credits from the local planning authority, you can purchase credits from an adjacent LPA at 0.75 of the score (Spatial Risk Multiplier).
Otherwise, buy statutory credits from the government (via Natural England), which are half the score (twice as expensive).
The above is set out so that developers give priority to the local area.
How long does buying Biodiversity Credits take?
The process with DEFRA can take 4-8 weeks.
How can I invest in BNG?
The council may already have available units to offer developers. Investors in biodiversity net gain may, however, offer a more competitive price and/or release units faster than the council (with a premium attached).
As for land ownership, habitats would ideally be pre-developed with units ready to be sold quickly, but that requires a fair amount of investment if the plan is to cover multiple LPA territories.
An investor could pay just to improve land, ecologically, and retain the right to buy/sell to developers as and when needed (much like an option). This would be lower cost than buying it all upfront and cultivating habitats before a developer approaches you for units. More sites could therefore be controlled with the former approach.
Either way, there would be a risk that part of your portfolio of land is not needed and some costs are wasted, but that should be outweighed by high demand.
How is biodiversity surveying carried out?
The surveying work could include habitat (classification), ecological appraisal, topographical, and soil surveys.
Once the ecologist completes the baseline assessment and habitat management and monitoring plan (HMMP), it gets sent to the local planning authority (LPA), and then to the online BNG sites register.
If a developer is unable to achieve net gain, then biodiversity credits are purchased as a last resort.
What is a biodiversity surveyor?
A biodiversity surveyor is a skilled profession that ensures compliance with biodiversity net gain conditions that are found in the 1990 Town and Country Planning Act Schedule 7A: https://www.legislation.gov.uk/ukpga/2021/30/schedule/14/enacted.
BNG assessors must have knowledge and skills in the science of mapping and calculating biodiversity net gain, which is the primary mechanism used to avoid or mitigate harm to biodiversity when human activities necessitate changes to land.
Does a survey establishing Biodiversity Net Gain reduce the need for other ecological surveys?
No. Using or requiring Biodiversity Net Gain does not negate any existing protections for biodiversity, statutory obligations, or policy requirements—such as a BS5837 survey of trees near or on the development site—that were already in place before Biodiversity Net Gain came along.
Who is able to conduct these Biodiversity Net Gain surveys, then?
A competent person must do them, and that competence must align with the British Standard (BS 8683:202) which covers the specific process for designing and implementing biodiversity net gain.
We strongly recommend that Biodiversity Net Gain surveys be completed by certified ecologists who not only understand a wide variety of habitats, protected species, and local planning policy but also know when to call for other kinds of ecological surveys that may be needed to make an application for permission secure in a way that safeguards biodiversity.
Off-site offsetting
When on-site measures can not yield Biodiversity Net Gain, off-site solutions can be employed (i.e. biodiversity credits). Contact us to learn more.
Landowners:
Property owners can sell Biodiversity Credits while engaging local authorities or brokerages in the process. These credits are accumulated when landowners improve biodiversity on their land.
To earn the credits, property owners must undergo an assessment process using the UK Government’s Biodiversity Metric. They first need to get in touch with local authorities or brokerages to schedule a property survey. The property is then assessed for biodiversity.
Local authorities and brokerages use the results from these assessments to determine “net gain”: a conservation term that describes whether property under development has improved, worsened, or stayed the same in terms of biodiversity.
Your consultant BNG surveyor can help you with the above (including guidance on landscaping to plant wildflower meadows, hedgerows, trees, etc.).
