Biodiversity Net Gain (BNG) Costs – Pricing, Units and Credits Explained
Biodiversity Net Gain (BNG) has become a legal requirement in the UK for most new developments, meaning projects must leave nature in a better state than before. If you’re budgeting for a development, you’ll need to account for BNG costs from the outset. These costs can be significant from the price of purchasing biodiversity units or credits, to long-term monitoring and management fees. In this guide, we break down the biodiversity net gain costs you can expect, why they matter, and how to budget effectively so you can achieve the mandatory 10% net gain without breaking the bank. By planning ahead and understanding BNG pricing, developers can avoid costly surprises and ensure compliance with new biodiversity net gain regulations 2024 in England. Let’s explore what you need to budget for BNG and how to keep those costs under control.
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Understanding Biodiversity Net Gain BNG Costs
Before diving into pounds and pence, it’s important to grasp what Biodiversity Net Gain involves. In simple terms, BNG requires developers to enhance the natural environment by 10% compared to its pre-development state. This enhancement is measured in “biodiversity units” using a standardised BNG calculator (the DEFRA biodiversity metric). Achieving net gain can be done on-site (e.g. creating new habitats or improving existing ones within the project) or off-site (funding habitat creation elsewhere). Either way, there are costs involved whether it’s paying for habitat works on your land, or buying credits/units from others. Understanding the types of BNG costs will help you budget realistically.
What are BNG Units?
A BNG unit is essentially a metric for biodiversity value. It quantifies how much nature is impacted or improved by a project. Ecologists assess the site’s habitats (type, size, condition, distinctiveness) before and after development using a government-sanctioned biodiversity metric.
The metric outputs a number of biodiversity units lost and gained. For example, a hectare of low-grade grassland might be worth 2 units, whereas a hectare of species-rich meadow could be, say, 5 units. Developers must not only replace what’s lost but deliver a +10% net gain so if your project causes a loss of 10 units, you need to provide 11 units of gain in total. These units are at the heart of BNG costs: if you can’t generate them on-site, you’ll need to obtain them elsewhere. Many people ask “What is a BNG unit?” simply put, it’s the accounting unit of biodiversity used to ensure a measurable net gain. The number of units required varies by project; larger or ecologically richer sites will involve more units. Using the BNG calculator (currently Biodiversity Metric 4.0) is essential to determine how many units your development must deliver or compensate for.
BNG Units vs BNG Credits: What’s the Difference?
It’s crucial to distinguish BNG units from BNG credits, as the terminology can affect your budgeting. Biodiversity units usually refer to the measurable units of gain or loss that can be delivered either on-site or via an off-site provider (often through a habitat bank or landowner). These units are typically traded on the open market between landowners (who create habitat to generate units) and developers (who need units to offset their impact). When you buy off-site compensation, you’re essentially purchasing biodiversity units. In contrast, biodiversity credits usually mean statutory BNG credits sold by the government (Natural England/Defra) as a last resort option. Developers can only resort to buying statutory credits if they cannot achieve BNG on-site or via any off-site units available privately. Off-site units are often informally called “credits” in conversation, but official guidance recommends avoiding that term for private trades, to not confuse them with government-issued credits.
From a cost perspective, off-site BNG units are usually less expensive and more flexible, negotiated in a marketplace of habitat banks and landowners. Statutory BNG credits, on the other hand, come at a premium fixed price set by Defra deliberately high to encourage developers to use other options first. In summary, if you see BNG units for sale, that refers to private market deals (typically a more competitive pricing environment). BNG credits for sale refers to the government scheme, which is only accessible with approval and at set rates. As a developer, you’ll want to aim to purchase units privately, since relying on credits will inflate your costs dramatically (as we’ll detail below).
Breakdown of BNG Unit Costs
When budgeting for Biodiversity Net Gain, one of the most common questions developers ask is: “what does a unit actually cost?” Unlike planning fees or statutory contributions, there’s no fixed national tariff. Instead, BNG unit costs reflect a developing marketplace shaped by supply, demand, habitat quality, and location. Prices have begun to settle as more habitat banks come online, but they still vary significantly. The following outlines current benchmarks, factors driving variation, and what you can realistically expect to pay per unit.
How much does a biodiversity unit cost?
The price of BNG units on the market isn’t fixed by law it’s driven by supply and demand, habitat type, and local policy. However, industry data from late 2024 provides a useful benchmark. On average, bng unit costs have been around £20,000–£30,000 per unit in many areas. For example, one report found average unit prices roughly ~£25,000 per unit in the early market.
Another analysis of 65 habitat banks across England showed unit prices stabilising in that range, though with significant variation by habitat and region. Low-distinctiveness habitats (like improved grassland) tend to be at the lower end of the price spectrum, whereas high-distinctiveness habitats (like wetlands or ancient woodland) command higher prices due to their scarcity and higher baseline value. Location also matters: in 2024, BNG units in southern England were slightly more expensive on average than in the North, reflecting development pressure and limited supply in the South East.
To illustrate price differences: a woodland unit might cost ~£35,000 in one region, while a wetland or river unit (watercourse habitat) could exceed £150,000 per unit in areas where those are scarce. In fact, data from Q3 2024 put watercourse units (rivers/streams) at ~£150k in the North and ~£165k in the South by far the priciest category. More common habitat units like neutral grassland or lowland meadow often ranged ~£25k–£40k. Keep in mind these figures are per biodiversity unit. The number of units you need depends on the biodiversity metric calculation, which can produce fractional units too. If you need, say, 5.4 units off-site, you must purchase at least that amount (rounded as required).
Condition of Habitat
It’s worth noting that distinctiveness and condition of habitat influence how many units can be generated per hectare, which in turn impacts costs. For example, one rural survey indicated creating a high-quality habitat could yield between 2 and 6 units per hectare, with each unit valued around £20k–£25k. This means a single hectare of new habitat might provide 2–6 units, translating to roughly £50k up to £150k in value per hectare.
So if your project requires 10 units off-site, you might be looking at securing on the order of a few hectares of habitat creation, at a cost easily in the hundreds of thousands of pounds. These are ballpark figures actual BNG unit cost quotes will depend on the specific habitat bank or provider, and whether the units are area units (for broad habitats), hedgerow units (measured per length of hedge), or river units (watercourse length) as defined by the metric.
Hedgerow units tend to be much cheaper (often a few hundred pounds per 0.1 km unit) and river units much more expensive (tens of thousands per 0.1 km), reflecting the difficulty of habitat creation. For instance, in 2025 hedgerow units might cost on the order of £500–£1,500 each, whereas river units (watercourse) could cost £40,000–£100,000+ each, according to some developer guides. Always obtain updated quotes or use a BNG costs calculator if available, because this market is evolving rapidly with new suppliers entering (and potentially driving prices more competitively).
Factors Influencing BNG Assessment Costs
Aside from the cost of buying biodiversity units or credits, developers need to budget for the BNG assessment process itself. A Biodiversity Net Gain assessment is usually carried out by ecological consultants and involves several steps: baseline habitat surveys (often season-specific surveys for flora and fauna), running the Biodiversity Metric calculation, preparing a BNG report and BNG plan, and sometimes liaising with planning authorities on the proposal.
The bng assessment cost will vary with the complexity and scale of your project. For a straightforward, small development (e.g. a single dwelling on a plot with one habitat type), a basic BNG report might cost in the low thousands of pounds. Many consultancies advertise packages for example, biodiversity net gain reports starting from around £400–£800 for very simple cases (e.g. a single-phase scheme with minimal habitat impact).
More commonly, BNG assessment fees range from ~£1,500 up to £5,000+ depending on site size. A figure of £2,000–£3,000 is typical for moderate projects, whereas large or complex sites (multiple habitat types, protected species issues, or needing detailed habitat management plans) could incur £5,000–£10,000 or more in consultancy fees.
What Factors influence the BNG Costs?
Several factors drive these costs: the survey effort required (a larger or ecologically rich site needs more person-hours), the analysis and design time (crafting ways to achieve net gain on-site can be iterative and complex), and the reporting requirements of the local authority. Some councils require a full Habitat Management and Monitoring Plan (HMMP) alongside the metric calculation, which adds to effort.
Additionally, BNG report cost may include advising on or sourcing off-site solutions if needed, which can involve negotiations with habitat banks or drafting legal agreements adding to consultant time. It’s wise to request quotes early and ensure the scope (e.g. does it include the Biodiversity Metric calculation, liaison with the council, revisions if needed, etc.).
By engaging BNG professionals early, you can avoid costly delays a well-prepared BNG plan can smooth your planning approval, whereas an inadequate one might lead to conditions that halt your project until extra units are secured.
BNG Credit Costs Overview
When on-site and off-site options are exhausted, developers have the fallback of purchasing statutory biodiversity credits from the government. However, these BNG credits cost considerably more than market-rate units. The government (Defra) released indicative credit prices in mid-2023 to guide planning.
These prices are tiered by habitat distinctiveness and type, and are intentionally set very high so that using credits is truly a last resort. Statutory credit prices are calculated based on the estimated cost to create, manage, and monitor habitats for 30+ years plus a hefty markup to avoid undercutting the private market. In other words, credits are priced to be more expensive than doing BNG through other means, ensuring developers try all other avenues first.
The credit pricing scheme in England divides habitats into broad categories of Low, Medium, and High distinctiveness, with further sub-tiers A1 through A5 for finer habitat types. Each tier has a fixed price per credit set by Defra, and these are reviewed periodically (every 6 months).
Cost of BNG Credits
As of the latest guidance, statutory BNG credits cost £42,000 per credit at the lowest tier, up to £650,000 per credit for the highest-value habitats. Specifically, the indicative prices published in 2023 are: £42,000 (Tier A1), £48,000 (A2), £66,000 (A3), £125,000 (A4), and £650,000 (A5) per credit. For context, low distinctiveness habitats (like general grassland, scrub, or urban habitats) fall in the lowest tier around £42k.
Many medium distinctiveness habitats (e.g. typical woodlands, moderate-value grasslands) range from £42k up to £48k per credit. Some specialized medium categories like lakes/reservoirs are priced much higher (~£125k). High distinctiveness habitats (the rarest and most valuable like certain wetlands or ancient woodland) are in the top tiers for example, creating a large lake or very rare habitat is pegged at £650k per credit. On top of these, linear habitat credits are separate: a hedgerow unit credit is ~£44,000, and a river (watercourse) unit credit is a whopping £230,000 per credit. These figures give a sense of how costly credits are in raw terms.
However, an even more important factor is the spatial risk multiplier that applies to credit purchases. Government rules say that because credits are not location-specific (unlike buying units ideally near your development), you must buy 2 credits for every 1 biodiversity unit you need. This multiplier effectively doubles the cost compared to the sticker price in the table (it’s applied automatically by the upcoming statutory metric tool). The rationale is to ensure using credits remains a last resort by making them twice as expensive as the damage you’re offsetting.
How Much Do BNG Credits Cost?
Taking the above into account, how much might a developer actually pay if they use credits? In practice, the real cost of BNG credits is double the listed price for the needed units. For example, if your project needs 1 unit of a low distinctiveness habitat and you opt for credits, you must buy 2 credits at £42k each £84,000 to cover what 1 unit would have delivered. At the top end, 1 unit of high distinctiveness habitat via credits could require 2 credits at £650k = £1.3 million. These are eye-watering sums. Even mid-tier cases: a woodland unit (medium distinctiveness) priced at £48k/credit becomes £96,000 per unit when doubled. It’s clear why credits are described as “uncompetitively priced” they are expensive, and finding a local solution may be more cost-effective.
The cost of BNG credits for developers thus hinges on both the per-credit price and the multiplier. Always calculate credits in terms of cost per biodiversity unit compensated, not per credit, to get the true budget impact.
BNG Credits Cost for Developers
For developers, the financial implication of using statutory credits is usually prohibitive. Let’s say a project is short by 5 biodiversity units after exhausting on-site measures. If those units are medium distinctiveness (tier A2, ~£48k/credit), buying credits means 10 credits × £48k = £480,000 cost. If they were higher tier habitats, it could run into the millions.
In the first year of mandatory BNG (2024–25), very few developers actually bought credits only around £200k worth of credits were sold nationwide, indicating developers found alternatives or projects were delayed. The government expects low use of credits (and indeed wants to see them as a last resort). Essentially, BNG credits cost so much that they act as a last-resort safety valve they allow a project to proceed if absolutely no units can be sourced, but at a steep price that ideally funds significant conservation work elsewhere.
When budgeting, plan as if credits are off the table unless you have confirmation that no units are available. The open market for BNG units will nearly always be more cost-effective than credits. In fact, the government’s credit pricing is calibrated not to undercut the private BNG unit market, so open-market unit prices should remain lower.
Knowing the credit prices can still be useful for budgeting a worst-case scenario or as leverage in negotiations (e.g. if a habitat bank is quoting very high prices per unit, a developer can point out the statutory credit as a ceiling benchmark albeit a very high ceiling!).
The Financial Implications for Developers
Now that we’ve covered unit and credit pricing, what do BNG costs mean for a developer’s bottom line? In short, Biodiversity Net Gain compliance introduces a new category of cost in development budgets. This can range from a minor expense on small, low-impact projects, to a major financial commitment on large or ecologically significant sites.
A 2023 study estimated the average cost burden to developers could be on the order of 5–10% of land development costs in some cases once BNG is factored in (this is highly project-specific). For many housing developers, the cost of achieving 10% BNG may translate to reduced margins unless land values adjust.
It’s therefore vital for anyone submitting planning applications to budget for BNG early and track these costs through the project lifecycle. Below we provide guidance on budgeting and often-overlooked expenses related to BNG.
Budgeting for BNG Compliance
When planning your project finances, treat BNG costs as you would any other required infrastructure or mitigation cost. First, determine how many biodiversity units you will need to deliver. This comes from conducting a BNG assessment (using the metric). Once you have an estimate (e.g. your project might need to provide 12 units in total, with a shortfall of 5 units off-site), you can start estimating costs. There isn’t a single universal “BNG costs calculator” provided by government for overall costs, but you can make use of several tools and resources:
- Biodiversity Metric Calculator: This won’t give costs directly, but it tells you the number of units required which is the basis for cost.
- Local authority guidance: Some councils have published tariffs or examples. For instance, a few early-adopting councils in 2021–2022 set informal per-unit contribution rates (often £10k–£15k per unit then, though these are rising).
- Monitoring fee calculators: Councils are allowed to charge developers fees for monitoring BNG delivery. A BNG monitoring fee calculator tool (like those some councils or consultants offer) can estimate what you’ll owe the council in monitoring (often a few hundred pounds per unit, see Hidden Costs below).
- Consultant or Broker Quotes: Reach out to habitat banks or BNG brokers for quotes on unit prices in the area. They can often give an indicative range (e.g. “units locally are trading at ~£25k each for grassland units”). You might also consult an online BNG unit price report if available, such as industry surveys.
BNG Offsetting
Once you gather this info, include a line in your budget for BNG offsetting. For example, if you anticipate needing 5 off-site units at ~£25k each, allocate £125,000 for unit purchase. Also include the cost of BNG assessment/report (as a professional fee), and any on-site implementation costs (like creating landscaping, translocating species, etc., which might be part of your construction or landscaping budget). Essentially, integrate BNG into your project cost plan from day one. This can help avoid nasty surprises where, at the end of planning, you suddenly have to scramble to find tens of thousands for a last-minute offset purchase. By comparison, if you budget early, you might design the project to reduce that need (which in turn saves money).
Hidden Costs Associated with BNG
Beyond the obvious costs of buying units or credits, BNG compliance carries some less obvious costs that developers should prepare for:
Long-Term Management and Monitoring
Any habitat created or enhanced for BNG must be maintained for at least 30 years. This usually means signing a legal agreement and committing funds for management. Off-site, the habitat provider factors management into their unit price (so you pay upfront). On-site, you’ll incur costs in your landscaping or estate management budgets over time. Some developers establish a 30-year management fund or bond as part of planning obligations.
Local Authority Monitoring Fees
Planning authorities are permitted to charge a monitoring fee to cover their oversight of BNG delivery. These fees vary by council but often scale with the size of the project and number of units. For example, a council might charge a few hundred pounds per year for major projects, or a fixed percentage of the BNG implementation cost. One GOV.UK note suggested monitoring costs could be around 10% of habitat delivery costs. Be sure to check your council’s policy some provide a formula or a BNG monitoring fee calculator (e.g. Lichfield, Blackburn and others have published calculators). Monitoring fees are typically a one-off payment or series of payments secured via the Section 106 agreement or as part of the conservation covenant.
Legal and Administrative Costs
To secure off-site BNG units, you’ll likely need to enter into legal agreements either a Section 106 agreement with the local authority and land provider, or a Conservation Covenant. There will be legal fees for drafting and reviewing these. Similarly, registering an off-site gain site on Natural England’s register incurs a fee (£100–£1000 depending on site size, though if you’re buying from an existing habitat bank, they handle that).
Opportunity Costs & Design Changes
Achieving BNG on-site might require using more land for green space, which could reduce developable area (an implicit cost). Or you might spend on certain design features (like wildlife crossings, green roofs) which have costs but count towards net gain.
Delay Risk
Possibly the biggest hidden “cost” is schedule impact. If BNG requirements aren’t met, planning permission could be delayed or a condition could stall your project until compliance is shown. Delay can carry financing costs and other penalties. Thus, investing in a robust BNG solution early on can save the cost of delays later.
By being aware of these ancillary costs from monitoring fees to long-term maintenance you can factor them into your pro forma. Many developers now treat BNG like any other regulatory cost (CIL, section 106 contributions, etc.), building in a contingency for it.
Strategies to Mitigate BNG Costs
While BNG undoubtedly adds costs, there are strategies to keep those costs manageable. How can developers reduce costs while still achieving BNG compliance? The key is proactive planning and exploring all available options for net gain. Here we outline several approaches below.
How to Reduce Costs While Achieving BNG Compliance
Design with BNG in Mind
The cheapest biodiversity unit is the one you don’t have to buy. By avoiding habitat loss on-site and integrating green infrastructure into your design, you can reduce the number of units you’ll need off-site. For example, retaining mature trees and enhancing them, or creating new wildflower areas on the margins of your site, could generate on-site units that count towards your 10%. This reduces the net deficit. It may require some upfront spending on landscape design or amenity space that doubles as habitat, but that is often far cheaper than buying units externally. Early collaboration between your planners, ecologists and designers is crucial – they can look at biodiversity net gain examples from other projects to incorporate cost-effective measures (like using native planting that scores well in the metric).
Phasing and Small Sites
Note that as of April 2024, even small sites must comply (the mandate was delayed slightly for small developments). However, small sites use a simplified metric. If you have a larger project, consider phasing it such that each phase’s BNG is managed, or aggregating on a strategic site to possibly deliver BNG more efficiently in one go.
Early Ecological Assessment
Don’t skimp on the initial BNG assessment. A thorough assessment can identify biodiversity risk management options upfront. Knowing in advance that you’ll need, say, 3 woodland units and 2 wetland units off-site gives you time to shop around for the best options (or even negotiate with local landowners) rather than last-minute credit purchases. Early assessments also help uncover if certain high-value habitats on-site will cause huge unit requirements if removed – you might decide to conserve those (avoid impact) and save cost.
Use Existing Initiatives
Explore if local or national schemes can help. For instance, some areas have local habitat banks or partnerships with wildlife trusts offering units at reasonable prices (sometimes cheaper than private brokers). The UK is also seeing emergence of marketplaces for units (such as online platforms) which increase price transparency and competition. You might find units at a better rate a bit further away, and even with spatial risk multipliers (if allowed by the LPA), it might total less cost. Also stay updated on any government funding or incentives e.g. grants for nature-based solutions or green infrastructure investment might indirectly support your BNG work.
Leveraging Off-Site BNG Units
If on-site measures alone can’t hit 10% (quite common in high-density developments), off-site units are your next port of call. The open market for BNG units offers flexibility, and prices may come down as more suppliers (farmers, land managers) enter the market. To leverage this:
Compare Unit Providers
Don’t assume the first quote is the only option. There may be multiple habitat banks serving your region. Prices can vary; for example, one landowner might offer grassland units at £22k each, another at £30k depending on their costs and how early you engage. In early 2025, developers observed a widening pool of habitat sites, which helped stabilize prices. Use a broker or marketplace if needed to solicit multiple offers.
Local Preference (Spatial Multipliers)
The closer the off-site is to your development, the more favorably the metric treats it (reducing any multiplier). Many LPAs prefer local offsets. So, while a unit 100 miles away might be cheaper in cash terms, it might count for less due to spatial risk. Ideally, seek units within the same Local Planning Authority or county. Some councils maintain lists of local land interested in BNG check with them.
Advance Agreements
If you have future projects, consider entering an agreement with a landowner now to secure a pipeline of units at a pre-agreed price. This hedges against market price increases as demand grows. Keep in mind any such agreements still need the sites to be registered and approved, but locking in say 20 units at today’s prices for use over the next 5 years could be savvy.
Statutory Credits as Ceiling
Use the price of BNG credits as a negotiation tool. For example, if an off-site provider is quoting an exorbitant price close to the government credit, you have the (difficult) option of saying you’ll just go to government. While not ideal, it might encourage a more reasonable deal since private providers know they need to stay below credit cost (Defra’s strategy is that credits set an upper limit).
In summary, treat off-site BNG units like any procurement: shop around, negotiate, and align with strategic needs. Many developers find working with local conservation organizations beneficial you might achieve BNG by funding a local nature reserve extension, for instance, turning a compliance cost into positive PR and community goodwill (and possibly at a fair cost if negotiated as a partnership).
Collaboration with Local Authorities
Early and open communication with your Local Planning Authority (LPA) can save you money on BNG. Councils are key gatekeepers they approve your Biodiversity Gain Plan and can sometimes help identify solutions. Some tips:
Consult the LPA Early
Many LPAs encourage developers to have a pre-application discussion about BNG. They might tell you upfront if there are known local initiatives or preferred approaches. For example, a council may have its own land earmarked for BNG offsets or a partnership with a local land trust. These could be cost-neutral or cheaper than market (since the goal is local environmental improvement, not profit).
Understand Local Policy Exceeding 10%
A few councils have signaled they want more than 10% (though 10% is the statutory minimum). If your LPA unofficially expects 20% net gain, that doubles your units critical to know for budgeting! Stay updated on biodiversity net gain regulations locally. Also check if the council has published any BNG SPD (Supplementary Planning Document) or guidance these often outline how they calculate contributions or any tariffs.
Explore Pooled Contributions
In some cases, rather than you individually finding land, a council might accept a cash contribution for BNG which they will pool to deliver larger projects. This isn’t universally available, but where it is, the council essentially sells you the units (or credits) at a set price. For instance, a council might say “if you can’t do it, pay £X per unit and we’ll use that to create habitat in our region.” Depending on the price set, this could be simpler and possibly cheaper than sourcing units yourself. Be cautious though, these are effectively like buying credits, so ensure the cost per unit is reasonable.
Local Nature Recovery Strategies (LNRS)
Every county is developing an LNRS mapping out where nature recovery (including BNG projects) should happen. Aligning your off-site BNG with these priority areas could make approval smoother. An LPA might be more lenient on certain metric rules if your units go to a strategic location identified in the LNRS. That could reduce any penalties or multipliers, effectively giving you more bang for your buck.
In essence, view the council not just as an authority to satisfy, but as a partner in delivering net gain. They have the same goal improving biodiversity and if you can find a collaborative route (like contributing to a council habitat creation scheme), it might streamline your process and control costs. Always document any agreements in the BNG plan for transparency.
Conclusion
Bringing a development to fruition in the era of Biodiversity Net Gain requires new considerations and careful budgeting. To recap, BNG costs primarily come from two sources: creating/enhancing habitats (on-site or off-site) to generate the required units, and administrative/long-term compliance costs (assessments, legal agreements, monitoring). A prudent developer in England should now approach projects with BNG in mind from the start it’s as integral as design, engineering, or any other planning factor. While the costs can be substantial, they are manageable with early action and informed choices.
Summary of Key Points
- Mandatory 10% Net Gain: From late 2023/2024, England’s BNG legislation requires most developments to deliver a 10% uplift in biodiversity. Non-compliance is not an option for planning approval, so BNG must be budgeted for.
- BNG Units vs Credits: Aim to fulfill net gain through on-site actions and/or off-site units. Statutory BNG credits are extremely costly (e.g. £42k–£650k per credit, doubled by multipliers) and should only be last resort.
- Typical Costs: Biodiversity unit prices in 2024–25 average around £20k–£30k per unit (more for certain habitats). BNG assessments and reports typically cost a few thousand pounds depending on project scope. Always obtain quotes and current market rates, as these are evolving.
- Hidden and Ongoing Costs: Don’t forget 30-year management commitments, monitoring fees payable to councils, and potential design trade-offs. These can add 10–20% on top of immediate implementation costs.
- Cost Mitigation: To control costs, integrate BNG into project design early (minimise off-site need), explore competitive options for off-site units (habitat banks, etc.), and coordinate with local authorities for any available schemes or guidance.
- Get Expert Help: Navigating BNG can be complex ecological consultants or BNG specialists can identify the most cost-effective compliance strategy (often their fee pays for itself by finding cheaper solutions or preventing delays).
By treating nature enhancement as an integral project component, developers can transform what might seem a burden into an opportunity delivering environmental value and smoother planning approvals. Budget wisely, act early, and you can turn BNG compliance into a win-win for both your project and local biodiversity.
Future Trends in BNG Costs
Looking ahead, the landscape of BNG pricing is likely to shift over time. On the supply side, more habitat banks are coming online every month, which could increase competition and potentially stabilize or lower unit prices in the open market. We’re already seeing price stabilization in some regions one year into BNG. On the other hand, if demand for units (from thousands of new planning applications) continues to surge, high demand might keep prices buoyant, at least for scarce habitat types.
The government will be reviewing statutory credit prices every six months these could be adjusted if needed, but expect them to remain high enough not to undercut the market. Regulatory tweaks are also possible: for example, changes in the metric or exemptions could affect costs for certain development types. The next year or two will also see the development of a more structured trading platform for BNG units, which should improve transparency in pricing. We anticipate that as natural capital accounting becomes mainstream and more landowners see the revenue opportunity, the BNG unit supply will grow, helping developers meet requirements more cost-effectively.
In summary, while current BNG costs might feel like a moving target, the trend is towards a maturing market. Staying informed through updates (such as Defra’s annual reports on BNG or industry surveys) will help you anticipate and adapt to these cost trends. Remember: investing in ecosystem service valuation and biodiversity now is not just a compliance task, but arguably adds long-term value to communities and developments an outlook that future-proofs your projects as environmental expectations continue to rise.
Our BNG Services & Process
Navigating the complexity of BNG can be challenging and that’s where we come in. We offer end-to-end Biodiversity Net Gain services to take the burden off developers and ensure you meet compliance cost-effectively. Here’s an overview of our process and how we work with you.
Initial BNG Assessment
Our team of qualified ecologists will conduct a thorough site survey and biodiversity audit. We calculate the baseline units using the latest Biodiversity Metric and determine the net gain target for your project.
BNG Plan & Design Integration
We collaborate with your design and planning team to incorporate on-site enhancements wherever possible – this could include creating green spaces, wildlife corridors, or other habitat features that boost your biodiversity score. Our goal is to maximise on-site gains (reducing what you need off-site) while fitting within your project’s constraints.
Off-Site Unit Sourcing
If off-site compensation is needed, we leverage our network of habitat banks, landowners, and brokers to find the most suitable and cost-effective BNG units for you. We’ll present options (including pricing and locations) so you can make an informed decision. Because we stay up-to-date on the BNG unit market, we often secure units at competitive rates – saving you money compared to going it alone.
Legal & Compliance Support
We assist in preparing the necessary supporting documents and plans to support your legal agreements advisors (Section 106 agreements or Conservation Covenants) to secure off-site units, and ensure all documentation (e.g. Biodiversity Gain Plan, management plans) meets the LPA’s requirements. We can coordinate with the local authority ecologists on your behalf, smoothing out the approval process.
Implementation & Monitoring
After planning approval, we don’t just disappear. We provide guidance on implementing on-site measures (e.g. planting schemes, habitat creation) to make sure the biodiversity outcomes are delivered. For off-site units, we liaise with the providers to confirm that management plans are in place. We also prepare the required monitoring reports for the council, typically at years 1, 5, 10, etc., to keep you compliant throughout the 30-year period. Our BNG Monitoring Fee Calculator service can estimate the council monitoring costs for your scheme, and we include that in our planning so nothing is overlooked.
Aftercare & Adjustments
If your project changes or regulations update, our team is on hand to adjust your BNG strategy. Biodiversity risk management is an ongoing process, and we’re your partners for the long term in ensuring your development’s net gain commitment is fulfilled with minimal hassle.
In summary, our full-service approach means you don’t have to become a BNG expert; you have one on your team. We pride ourselves on practical solutions that satisfy regulators while controlling costs for you.
Why Choose Us for BNG Compliance
Choosing the right consultant can make a huge difference in both the outcome and cost of your Biodiversity Net Gain efforts. Here’s why clients across England trust us to deliver BNG solutions that work.
Expertise & Experience
We are UK-based BNG specialists with a deep understanding of the latest biodiversity net gain legislation and metric. Having worked on a number of projects already under the new law, we know exactly what local authorities are looking for and how to meet those requirements efficiently.
Cost-Effective Solutions
Our ethos is “avoid needless cost.” We creatively explore on-site opportunities first to minimise expensive off-site purchases. When off-site units are needed, our industry connections often unlock better pricing. Simply put, we aim to save you more than our fee. (And we’ll be transparent, if your scheme can achieve net gain with a simple tweak rather than pricey offsets, we’ll tell you!)
All-in-One Service
Unlike firms that only do the assessment and leave you to source units, we handle the entire process, from initial survey to brokering units to post-development monitoring. This integrated approach ensures nothing falls through the cracks, and you’re not left hiring multiple parties (which could increase your costs and coordination effort).
Local Knowledge
We have up-to-date knowledge of local BNG policies and available habitat banks across different counties. This means we can quickly identify the best local solution for your project, whether it’s a council-run scheme or a private habitat bank, often faster than you could by searching from scratch.
Quality & Compliance Assurance
Our BNG reports and plans are meticulously prepared and double-checked against LPA checklists and the British Standards for BNG (BS 8683, if applicable). That track record of quality means our submissions sail through planning in most cases, avoiding costly resubmissions or delays. We also stay ahead of any changes in regulations – so you can be confident your strategy will be compliant not just now but for years to come.
Client-Focused Approach
We understand development is fast-paced. We pride ourselves on responsiveness and clear communication. When you have questions about BNG (and you will!), we explain them in plain English and give actionable advice. Think of us as part of your team, invested in your project’s success.
Innovation & Tools
As part of our service, you get access to our in-house tools such as the BNG Monitoring Fee Calculator and template management plans – ensuring you’re not paying for reinventing the wheel on every project. We’re also exploring natural capital accounting approaches to help demonstrate the broader value your development’s BNG actions bring – a useful narrative for stakeholders and planning committees.
Ultimately, our goal is simple: make BNG compliance easy and beneficial for you. With our help, you can turn what might feel like a regulatory headache into a smooth, streamlined process that adds value to your development.
Ready to ensure your project achieves biodiversity net gain without unnecessary cost or drama? We’re here to help from day one.
In the past year, we’ve delivered over 750 audit-ready reports supporting 400+ projects for developers, planners, and architects nationwide. We put quality over quantity and build lasting relationships based on trust, ensuring your planning applications are backed by robust evidence and delivered on time.
You can also drop us an email at hello@acp-consultants.com and we’ll get back to you within 24 hours to help with your inquiry!
Frequently Asked Questions (FAQs) on BNG Costs & Compliance
Understanding Biodiversity Net Gain (BNG) costs can feel complex, especially when unit prices, statutory credits, and long-term management fees all play a part. To help, we’ve answered the most common questions developers and planners ask about BNG unit cost, BNG credit prices, assessments, and reporting. These FAQs give you a clear overview of what to expect, so you can budget confidently and stay compliant with the biodiversity net gain regulations 2024.
What is a BNG unit and how is it calculated?
A BNG unit is a measure of biodiversity value used to quantify losses and gains for Biodiversity Net Gain. Ecologists calculate units using a biodiversity metric tool that considers habitat size, type (distinctiveness), and condition. First, the site’s baseline units are measured (existing habitats). Then the post-development units are calculated after accounting for any new habitats or enhancements. The difference (with a +10% requirement added) determines how many units you must deliver. For example, if a site is worth 10 units before and 5 units after development, you have a 5-unit loss and would need to add 5.5 units (which is +10% net gain) through on-site improvements or off-site compensation.
How much does a Biodiversity Net Gain assessment cost?
The cost of a BNG assessment (including the survey and report) can range widely depending on project size and complexity. Simple BNG reports for a small development might start around £1,500. More complex assessments for larger sites typically run £3,000–£7,000, and extremely large or multi-phase projects could be higher. Prices cover ecological surveys, running the BNG metric, and producing the Biodiversity Gain Plan report. It’s wise to get a tailored quote, as factors like needing detailed habitat management plans or seasonal wildlife surveys will increase the cost. Some consultancies (like us) offer fixed-fee packages for standard projects to give you cost certainty.
How much do biodiversity units cost to buy?
Biodiversity unit costs on the open market currently average about £20k–£30k per unit for many habitat types. Common habitat units (like grassland or basic woodland) might be in the £15k–£25k range each, while scarce or high-value habitat units (like wetland, ancient woodland) can cost significantly more sometimes £50k+ or even into six figures for specialized cases. Prices also vary by region; units in Southeast England (where development pressure is high) have been known to cost a bit more than those in the North. It’s important to get current quotes, as this is a new market. Early data from 2024 showed, for example, woodland units around £30k–£40k, pond units ~£60k in some areas, and river units well over £100k. Over time, these may change as more habitat banks supply units. Always check if the price includes the full 30-year maintenance; reputable providers’ prices usually do.
How much do BNG credits cost?
BNG credits (from the government’s statutory scheme) are very expensive. The base prices range from £42,000 per credit for low distinctiveness habitats, up to £650,000 per credit for the most distinct habitats. And remember, you need 2 credits per 1 unit required (due to the multiplier), effectively doubling those costs. So, in practice, one biodiversity unit via credits could cost between ~£84,000 (if low distinctiveness) to £1.3 million (if high distinctiveness). There are also specific prices for linear habitats: hedgerow credits ~£44k (so ~£88k per hedgerow unit after multiplier) and rivers ~£230k (so ~£460k per river unit). These prices are set by Defra and may be reviewed periodically, but they will remain high to encourage use of cheaper on-site or off-site unit options first.
How can I reduce the costs of achieving BNG compliance?
To reduce BNG-related costs, start by maximising on-site net gain. Preserve existing valuable habitats (to avoid large unit losses) and incorporate new habitat features into your development (like wildflower areas, ponds, native landscaping) to generate gain on-site. Every unit you achieve on-site is one less you have to buy. Next, if you need off-site units, plan early and shop around. Engage with potential habitat banks or landowners during the planning stage rather than after approval you might find more competitive prices and suitable local sites.
Another tip is to design your project in phases: sometimes you can sequence habitat creation such that earlier phases generate units that offset later impacts, smoothing out the need to buy units. Also, ensure your BNG report is thorough and accurate; overestimating impacts could make you buy more units than necessary, whereas a well-justified assessment might save units.
Finally, consult with the local authority some have strategic initiatives or can accept a local tariff instead of you doing it all, which could be simpler (though be sure to compare the cost). In short: avoid, minimise, and plan avoid habitat loss where you can, minimise what you must offset, and plan for the rest as efficiently as possible.
Do BNG costs apply to small developments and housebuilders?
Yes albeit with some differences in process. From April 2024, small sites (for residential, that’s sites under 10 units or under 0.5ha; for non-residential, under 1000 m² floor space or under 0.5ha) are required to achieve 10% net gain just like large sites. The government provided a simplified metric for small sites to make the process easier, but the obligation is still there. This means even a single new home on a plot will need to demonstrate net gain (unless exempt, like self-builds temporarily have some exemptions until 2025).
The costs for small developments may be lower in absolute terms (because the number of units required is smaller), but proportionally they can still impact a small builder’s margins.
One relief is that some local authorities may manage small site BNG through simpler means for instance, they might allow use of a small sites metric calculator or take a small cash contribution in lieu of actual habitat creation if the amounts are trivial. Always check the latest guidance for small sites. If you’re a small developer, it’s recommended to still do an early BNG assessment you might find you only need to plant a enhanced hedge or improve a bit of habitat on-site to meet 10%, which could be done for a few hundred pounds rather than paying a larger fee.
What happens if I can’t achieve 10% net gain on-site?
If on-site measures alone can’t get you to the +10% goal (which is common, especially in high-density projects), you will need to go off-site. Practically, this means either: (a) purchasing biodiversity units from a third-party habitat provider (private or through a conservation group), or (b) as a last resort, buying statutory biodiversity credits from the government. The first step is to try to find an off-site solution identify habitat banks or landowners who have or can create the needed units. This will involve a legal agreement (ensuring those off-site works are linked to your planning permission).
If no off-site units are available or suitable (and you can evidence that you tried and couldn’t find any), only then would the planning authority allow you to use statutory credits. You’d pay the credit fee to the government, which then uses those funds for nature projects. Importantly, you must outline your off-site plan in your Biodiversity Gain Plan submitted with your application. If you don’t address a shortfall (i.e. you show net gain not met and have no off-site solution), the LPA cannot legally grant permission. So it’s critical to have a plan for any deficit. In short: if you can’t do it on-site, you must do it off-site (one way or another) for your project to proceed.
Are biodiversity net gain credits available for sale now?
Yes, as of early 2024, the statutory biodiversity credits system is live but it’s not like an open marketplace or exchange where you shop around. To “buy” credits, a developer needs to apply through Natural England’s system, demonstrating that no on-site or off-site options exist. Once approved, you pay the government for the required number of credits (via the online credit sales service). The credits aren’t a tradable commodity you can purchase freely; they’re more like a transaction with the government.
On the other hand, biodiversity units (not called “credits” in this context) are available for sale on the private market you might find them via habitat bank operators, land agencies, or brokers. These are negotiated transactions and can often be tailored to your needs (specific habitat type, location, etc.). In summary: if you search for “BNG credits for sale,” you’ll likely be pointed to either the gov.uk portal for statutory credits (if you truly have no alternative), or to marketplaces for biodiversity units (which is where most developers will go first). Always ensure any off-site units you buy come from a registered habitat site or one that will be registered, otherwise the LPA cannot count them.
Is Biodiversity Net Gain legally required in 2025 and beyond throughout the UK?
The 10% mandatory Biodiversity Net Gain requirement is part of England’s Environment Act 2021 and relevant secondary legislation, and it applies to England (planning applications under the Town and Country Planning Act) from late 2023/early 2024 (February 2024 for most, April 2024 for small sites). As of 2025, it is not yet law in the other UK nations (Scotland, Wales, Northern Ireland) though they have their own biodiversity initiatives. Wales, for instance, has talked about similar measures but with different specifics (and some local Welsh authorities require some net benefit already via policy). Always check the local regulations for your project’s location. In England, assuming you’re within scope (virtually all developments bar a few exceptions like permitted development, householder extensions, or NSIPs which follow separate process), you must comply.
The biodiversity net gain regulations set out in 2023 detail the process. This includes the need to submit a Biodiversity Gain Plan as a condition of planning. The bottom line: in England, BNG is a legal requirement you must budget and plan for; elsewhere in the UK, it’s best practice or emerging policy but not yet a mandated 10% (subject to change as devolved governments consider their own laws).
What is natural capital accounting and how does it relate to BNG costs?
Natural capital accounting is an approach to quantify the economic value of natural assets and ecosystem services (like clean air, water, recreation, carbon storage). In the context of BNG, it’s a way to frame the costs (and benefits) of biodiversity enhancement. For example, spending £100k on habitat creation for BNG isn’t just a regulatory cost; in natural capital terms, that habitat provides services (pollination, flood mitigation, amenity value) that can be valued in monetary terms, often exceeding the initial investment over time. Some forward-looking developers use natural capital accounting to communicate to stakeholders or investors that the money spent on BNG is actually creating long-term value (not to mention de-risking the project from an environmental compliance perspective).
While it doesn’t reduce the immediate out-of-pocket cost, it can be helpful in project appraisal and demonstrating net environmental gain in a broader sense. Additionally, as policies evolve, there may be opportunities to get credits or funding for things like carbon sequestration or nutrient reduction from the same actions you do for BNG effectively stacking benefits. Natural capital accounting provides the framework for these multi-benefit analyses. In sum, it’s a strategic way to look at your BNG costs not just as a line item expense, but as an investment in natural capital that yields returns (direct or indirect) to society and potentially to your project (through goodwill, faster approvals, or future ecosystem service markets).
Additional FAQs on BNG Costs & Pricing
While our main FAQs cover the essentials, many developers and planners also ask more detailed questions about historic benchmarks, calculators, and specific terminology. The following additional FAQs on BNG costs and pricing address these niche queries to give you complete clarity when budgeting for biodiversity net gain.
Is there a BNG costs 2021 benchmark I can use today?
Early BNG costs 2021 pilots showed lower per-unit figures due to limited demand and immature supply. Current prices reflect a mature market. Always use up-to-date quotes for budgeting.
Do you have a biodiversity net gain costs calculator I can use?
Yes. Our team provides a biodiversity net gain costs calculator (scenario tool) to estimate units, on-/off-site mixes, and monitoring fees. It’s ideal for early viability and sensitivity testing.
How many BNG credits per hectare do I need?
There isn’t a fixed how many BNG credits per hectare rule. The metric calculates units from habitat type, size, and condition. Only any residual unit shortfall converts to credits, and credits carry statutory multipliers.
What is the biodiversity net gain cost per unit on the open market?
Typical biodiversity net gain cost per unit is c. £20k–£30k for many habitats, with higher figures for scarce habitats (e.g., watercourse). Always confirm with current supplier quotes.
What is the biodiversity net gain assessment cost?
The biodiversity net gain assessment cost for most small to mid-scale schemes is usually £1,500–£5,000+, depending on surveys, complexity, and reporting (metric, BGP, HMMP).
What is the biodiversity net gain credit cost vs unit prices?
The biodiversity net gain credit cost (statutory credits) is set higher than market units and is doubled by spatial multipliers. Use credits only as a last resort after on-/off-site units.
What is the biodiversity net gain credits cost for developers in practice?
The biodiversity net gain credits cost depends on habitat tier and the 2x multiplier. For budgeting, calculate cost per biodiversity unit compensated, not per credit headline.
What does biodiversity net gain report cost usually include?
A biodiversity net gain report cost typically covers baseline survey, metric runs, the Biodiversity Gain Plan, and coordination with the LPA. Extras (e.g., protected species surveys, HMMP, legal support) may add fees.
Does this guidance apply across Biodiversity Net Gain UK?
Biodiversity Net Gain UK policy differs by nation. The mandatory 10% regime applies in England. Check local policy if your site is in Scotland, Wales, or Northern Ireland.
What is the ‘BNG conserve cost’?
BNG conserve cost refers to the long-term spend to conserve and manage created/enhanced habitats over 30 years. On-site it sits in your estate/management budgets; off-site it’s embedded in unit pricing.
References
- Guidance: Statutory biodiversity credit prices.
- Guidance: Estimate the cost of statutory biodiversity credits.
- Biodiversity Net Gain Monitoring Fees. Torridge District Council.
- Biodiversity net gain legislation 2024. UK Statutory Instruments.
- Guidance: Understanding biodiversity net gain.
- Creating a habitat management and monitoring plan for BNG. Defra.
- Biodiversity Net Gain (BNG) – Habitat banks, monitoring, and fees. East Devon District Council.
- Register your interest in a legal agreement to regulate an off-site biodiversity net gain site. Buckinghamshire Council.
- Exemptions & de minimis thresholds – Householder, small self-build, and very small impacts where no priority habitat is affected. Exemptions Guidance (GOV.UK) and Defra Environment Blog.
- Statutory biodiversity metric – How units are calculated, modules, factors, and guidance on early use. Statutory Metric and User Guide (GOV.UK).
- Statutory framework & planning condition – Biodiversity Net Gain under Schedule 7A of the Town and Country Planning Act 1990; statutory regime explained in Planning Practice Guidance (GOV.UK)
- Securing off-site Biodiversity Net Gain: Expert legal perspectives. Natural England.
- Guidance: Make off-site biodiversity gains as a developer. Defra.
- BNG in Practice Report (2025) – Case studies showing how BNG is being delivered in real projects. Institute of Environmental Sciences.
- Biodiversity Net Gain – Principles and Guidance for UK Construction and Developments. Chartered Institute of Ecology and Environmental Management.
- BNG Research Briefing – This post note outlines the mandatory biodiversity net gain policy introduced in England in 2024 and the risks and challenges for delivering its objectives. UK Parliament.
- Biodiversity net gain: where to start. Natural England.
- Biodiversity Net Gain Report and Audit Templates- CIEEM.
- Implementing statutory biodiversity net gain. NAO.
- Mandatory Biodiversity Net Gain in England. A Guide by CIEEM.
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Understanding the costs of delivering Biodiversity Net Gain (BNG) is key to accurate project budgeting. To see how financial planning fits within the wider BNG process, begin with the Biodiversity Net Gain Overview and BNG Assessment Guide, which explain how habitat condition and distinctiveness influence overall unit value.
Learn to calculate biodiversity units using the Statutory Biodiversity Metric 4.0 or Small Sites Metric (SSM), then prepare accurate documentation through the Biodiversity Gain Plan (BGP) and Habitat Management and Monitoring Plan (HMMP).
To understand long-term obligations, visit our BNG Monitoring Fee Calculator and review Off-Site Biodiversity Units, which can affect cost and delivery strategy. For compliance and legal context, explore BNG Legislation & Guidance and see real-world outcomes in our BNG Case Studies & Portfolio.
You can also drop us an email at hello@acp-consultants.com and we’ll get back to you within 24 hours to help with your inquiry!
- Last Updated:
- October 2025
Disclaimer: Our content is prepared by ACP Consultants’ in-house specialists and is based on current guidance, standards, and best practice in environmental consultancy. While we make every effort to keep information accurate and up to date, it is provided for general guidance only and should not be relied upon as a substitute for professional advice on specific projects. Planning authorities retain final decision-making powers, and requirements may vary between local authorities and over time. ACP Consultants accepts no liability for any loss arising from reliance on this content without obtaining tailored advice for your project.