Frequently asked questions
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What is Biodiversity Net Gain?
Biodiversity Net Gain is a policy that contributes to the enhancement of nature due to development. BNG is based on the principle that all projects must leave a site with more natural resources than before their commencement.
What is the Biodiversity Gain Site Register?
The register is an online public record of off-site BNG delivery sites, their baseline units and owners. Off-site solutions can only be used if the site is registered. Landowners and habitat banks must pay a fee to register their gain sites.
Who does BNG matter to?
Given the importance of ecosystem services, Biodiversity Net Gain is in everyone's interest. Mandatory BNG legislation will mainly affect developers and local authorities, who must now consider novel approaches to development. BNG also matters to land managers, who can sell biodiversity units to companies wishing to offset their development.
Why do we have BNG?
According to the 2023 State of Nature report, 38% of Britain's terrestrial and freshwater species showed a substantial or moderate decrease in abundance over the last decade. This is due to pressures such as climate change, intensive agriculture and overexploitation. These activities also affect valuable ecosystem services such as climate and erosion regulation, nutrient cycling, soil health, and human well-being, among many others. BNG aims to gradually restore natural resources to reverse negative impacts on wildlife and ecosystems.
Is BNG now mandatory?
Statutory BNG requirements for most sites are mandatory as of Monday, February 12, 2024, and for small sites from Tuesday, April 2, 2024. Permitted developments and Nationally Significant Infrastructure Projects (NSIPs) are exempt.
Is BNG a legal requirement?
The Environment Act 2021 requires most developments to achieve a minimum 10% increase in biodiversity levels from the pre-development baseline, as calculated using DEFRA’s Statutory BNG Metric.
When can BNG surveys be carried out?
Unlike many other ecological surveys, we can conduct BNG baseline assessments anytime. We try to conduct surveys during spring and summer to produce the most representative account of the botanical species present. Baseline surveys are often carried out alongside a Preliminary Ecological Appraisal, which will determine if further ecological surveys are required.
Do I need to secure my habitat creation for 30 years?
Some habitats are exempt from the 30-year management period. On-site, non-significant habitats can be secured without being secured. Non-significant habitats may include private gardens and planters but are highly relative to the site and generally evaluated by the LPA. On-site significant and off-site habitats must be secured for 30 years.
I'm part of a Local Planning Authority; what must I do?
Planning authorities are more concerned with the delivery of BNG to developers and landowners. This may involve approving planning applications with more than 10% BNG, facilitating unit trades, verifying metric calculations, and checking baseline surveys, among many other roles. LPAs also have the power to include precious habitats in their local nature strategy, which can receive 15% more biodiversity units than other sites. We work closely with LPAs to verify and advise on planning requests.
What is habitat banking?
Habitat banks are areas of land procured for their BNG potential that developers can fund to generate off-site units. Those investing in habitat banking can expect economic and environmental returns.
As a landowner, can I sell biodiversity units as well as sell into other natural markets?
Biodiversity units have the potential to be 'stacked' with other natural resources such as carbon credits.
I'm a land manager; what do I need to do?
Many landowners want to sell biodiversity units in the off-site BNG market. Generally, your priority is generating as many biodiversity units as possible. Our assessment service is most helpful in establishing a baseline value and a potential gain value. You may then decide to continue with habitat design and creation to sell units on demand or agree to work with a developer to match their needs precisely. Some landowners register their land as a habitat bank with an external management company. Either way, you must record your land on the biodiversity register and produce an HMMP. Many landowners want to sell biodiversity units in the off-site BNG market. Generally, your priority is generating as many biodiversity units as possible. Our assessment service is most helpful in establishing a baseline value and a potential gain value. You may then decide to continue with habitat design and creation to sell units on demand or agree to work with a developer to match their needs precisely. Some landowners register their land as a habitat bank with an external management company. Either way, you must record your land on the biodiversity register and produce an HMMP.
Can I buy statutory biodiversity credits instead?
Statutory credits are available to buy from the government to offset developments. These credits are invested in national landscape-scale projects. This is a last-resort way to achieve BNG, which is much more expensive than generating biodiversity units. You must provide evidence that on-site and off-site biodiversity unit generation is impossible.
I'm a developer; what do I need to do?
Developers will need proof of an agreement to deliver a 10% net gain and manage it for 30 years to secure planning permission from the local authority. Before applying, it is recommended that you check the Local Planning Authority's BNG requirement, identify habitats of high strategic significance, and gather evidence to show how you are planning to follow the BNG hierarchy.
A Biodiversity Statement is The minimum legal requirement for submitting a planning application. This document outlines whether or not you are exempt from BNG requirements, and evidence should be provided to justify your status.
After the application has been conditionally accepted, you must provide a Biodiversity Gain Plan. This document includes information on the proposed works, developer details, metric calculations, pre- and post-development biodiversity unit values and appropriate monitoring measures. You must also provide a Habitat Management and Monitoring Plan containing all habitat creation and management details. Work can start once the biodiversity gain plan has been approved, which can take up to 8 weeks. Therefore, we recommend that a gain plan is formulated early in the process.
How long does it take?
The time you need to achieve your requirements depends on the services you choose. We can usually assess a site and produce a Biodiversity Net Gain Appraisal and Strategy report within a few weeks. Designing a Landscape Masterplan and Habitat Maintenance and Monitoring Plan will likely require a similar amount of time. Should you choose to use these two services, you can register your land as a habitat bank or successfully apply for planning permission within a year.
Why should I consider BNG now?
Developers must prepare in anticipation of planning applications, as front-loading BNG information can help speed up the process. Leaving BNG documents until the last minute could hugely delay your project. Land managers may find it beneficial to undertake surveys and begin habitat creation early to be in the position to sell units on demand into the off-site market.
How much does it cost?
Cost is dependent on the services required and the site itself. Every site is different.
What type of clients do we work with at Maydencroft?
We provide environmental services to many clients, including local authorities, developers, habitat banks, charities, and private clients.
Can Maydencroft sell my BNG units?
Whilst we are specialists in all aspects of BNG design and delivery, our services do not extend to the trade-in units. However, we work closely with several BNG brokers with whom we can connect you.
What guidelines do we follow?
All of our BNG reports are produced by British Standard BS8683 and the collaborative guidelines from CIEEM, IEMA, and CIRIA's Biodiversity Net Gain: Good Practice Principles for Development.
What services do I need?
During a project, you will require a BNG Baseline Assessment, a BNG Appraisal and Strategy, a Landscape Master Plan, and a Habitat Management and Monitoring Plan (HMMP). These reports will inform the procedure for habitat creation and longer-term management.
How does BNG impact irreplaceable habitats?
Loss of irreplaceable habitats cannot be compensated through the 10% BNG requirement and will require bespoke compensation to be agreed upon with the local authority. Irreplaceable habitats include ancient woodland, ancient and veteran trees, lowland fens and blanket bog.
How does BNG operate alongside other environmental policies?
If habitat creation through a separate policy is required on-site, for example, protected species mitigation, the new habitat can be counted as BNG habitat creation, and the total amount may be used in metric calculations. If the new habitat is off-site, it can count towards BNG but only up to no net gain (0%). It may offset development but cannot contribute to the required 10% gain.
Does the metric include protected species?
The biodiversity metric is a habitat-based approach to measuring biodiversity, focusing on what species need from the environment to thrive. As such, protected species surveys are not included in the BNG assessment, and additional surveys must be carried out separately if necessary.
How much are Statutory biodiversity credits worth?
The value of Statutory biodiversity credits is purposefully inflated to ensure they are only purchased as a last resort. Prices range between £42,000 and £650,000 per credit, depending on habitat type and distinctiveness.
How much are BNG units worth?
Prices are variable and subject to market fluctuations, but units have been traded at values between £20k and £35k.
What are my options if I can't achieve BNG on-site?
If you have shown that BNG is impossible on-site, your next option is to purchase off-site biodiversity units. You may find a gain site via online marketplaces or through the LPA, and you must allocate the off-site units to your development before work can start.
Statutory biodiversity credits are available to purchase as a last resort where on-site and off-site BNG is impossible. They are costly to deter overuse, and you must provide evidence that other options are not viable. The money is used to fund landscape-scale nature recovery projects.
Does BNG need to take place on the development site?
On-site BNG delivery is preferable but optional. It is most beneficial for wildlife to create habitats near where they have been lost so that animals can migrate into them. The LPA will require evidence to show that BNG is not possible on-site if you wish to utilise off-site options.
Is BNG required for homeowners?
Permitted developments that do not require planning permission are exempt from BNG. This includes improvements, alterations, and enlargements of an existing house. Extensions up to 50% of the curtilage are covered as permitted developments. Homeowners wishing to carry out work not classed as permitted development will have to file a planning application and deliver BNG on their development.
What is the Small Sites Metric?
The Small Sites Metric (SSM) is a condensed version of the statutory Metric designed to simplify calculations for sites with few, small habitats. Residential developments of 1-9 dwellings under one hectare and commercial developments under 1,000 square metres of floor space qualify for the SSM. The SSM cannot be used for sites containing priority habitats, designated sites and protected species, or mineral extraction or waste developments.
What is the Biodiversity Metric?
The Statutory Biodiversity Metric quantifies a site's biodiversity value. It considers habitat size, distinctiveness, condition, strategic significance, time to target condition, difficulty of creation, and spatial risk, with the resultant value measured in biodiversity units.
What is the monetary value of nature?
Ecosystem services and natural resources contribute billions of pounds to the UK economy annually. Loss of these services would impose huge costs.
How long must projects be maintained?
Following the completion of a development, the BNG schemes must be managed for a further 30 years to ensure the condition is maintained. The management must be upheld if the site is sold or given to a successor.
What happens after the 30 years of management?
Following the management period, the landowner chooses the site's future. Financial incentives exist to keep the land under management by selling units to the off-site BNG or other growing nature markets. Special consideration is given to woodland creation, which takes longer to reach its target condition.