Biodiversity Net Gain (BNG) is now a core part of planning in England. Most residential schemes must show a minimum 10% uplift using the statutory biodiversity metric, and secure that uplift for 30 years through a legal agreement (typically s106 or a conservation covenant). Statutory credits exist, but they’re priced as a last resort. If BNG feels like it’s about to derail your programme, residual, or sales strategy, you’re not alone – and you’re not stuck.
If BNG is affecting the viability of your development scheme, we can help to mitigate its impact. We can support developers with BNG, and reveal hidden value in your land, to help unblock your scheme due to biodiversity net gain legislation.
Intelligent Land’s Land Value Accelerator™ (LVA Method™) treats BNG for developers as a design and procurement variable so you can reach compliance at the lowest viable cost, without killing density or momentum to market.
Below is practical BNG guidance for developers struggling to make their plan profitable. Learn why you need BNG units, how to build a 30-year plan, and how Intelligent Land’s LVA Method™ finds the cheapest compliant route.
What developers need to know about BNG
BNG is mandatory for most new housing applications (major sites from February 2024, small sites from April 2024). The measurement is standardised: you’ll use the statutory biodiversity metric – or the Small Sites Metric where applicable – to evidence your uplift in biodiversity units. Those units are secured for three decades through enforceable management and monitoring.
Crucially, government credits are not meant to undercut the market; they’re a safety net when on-site and off-site routes genuinely cannot deliver. Understanding how this policy impacts BNG for developers, the logic above, helps you approach BNG as an options problem, not an automatic cost sink.
Why do housing developers need BNG units?
Because BNG is a planning requirement for developers. Your application must demonstrate that the completed scheme delivers at least 10% more biodiversity units than the pre-development baseline.
There are three legitimate ways to assemble those units, as part of our advice on biodiversity net gain / BNG for developers.
1. Change layout and specification
First, you can create units on site by changing the layout and specification by improving SuDS planting, introducing green roofs or walls, protecting and enhancing hedgerows and watercourses, and writing stronger management prescriptions.
Many of these changes are about how you landscape and maintain, not just about giving up developable land.
2. Secure BNG units off-site
Second, you can secure units off site by purchasing from an approved gain site within the appropriate geography, or by creating and registering your own off-site land (for example, from a wider landbank).
This is often where savings emerge if on-site gains are tight and space is at a premium, provided you source the right habitat types and providers with credible delivery and monitoring plans.
3. Buy statutory credits
Third, you can buy statutory credits from government, but only after demonstrating that on-site and off-site routes can’t bridge the gap. Credits are deliberately priced above market levels. Over-reliance can increase costs and, in some planning contexts, can play poorly at committee compared with a balanced on-/off-site strategy.
In practice, most schemes end up with a blend: some carefully designed on-site uplift, a tranche of off-site units to cover shortfalls, and a small credit contingency for risk. The commercial trick is to minimise cost per unit while protecting Net Internal Area (NIA) and programme.
The commercial impact: why BNG feels like a “cost” for developers (and how to reframe it)
For developers, BNG “10% uplift plus 30 years” reads as capex, opex, and potential land take. Left late, BNG can force development redesigns, push you into premium credits, and create validation friction. But BNG also rewards better specifications and smarter procurement. Edge treatments, tree strategy, SuDS palettes, species mixes and management standards can all move the needle without surrendering plots. Meanwhile, local off-site unit markets are maturing; scanning them early helps you avoid the credit premium and present a cleaner, faster route to consent.
Reframing matters.
A credible BNG plan for your development, de-risks determination and reduces the sort of vague conditions that can stall starts on site. It also supports a stronger ESG narrative for funders and partners and, when handled well, can contribute to place-making that improves absorption and pricing.
Intelligent Land’s position is simple: treat BNG like any other value lever, test the options, and choose the cheapest compliant pathway that keeps density and GDV intact.
To find out how we can help with this, book a quick call with us, and read more about how we work.
How do housing developers create a BNG plan?
The sequence of BNG for developers is straightforward, but the order is critical.
Establish the baseline early: Commission competent ecology, identify every habitat within the red line, and run the statutory metric to fix a realistic pre-development baseline. Flag irreplaceable habitats and any constraints that will drive the shape of your layout. Many expensive BNG development problems originate from guesses made before the baseline was understood.
Design for on-site gains – but smartly: Before you sacrifice plots, look for units you can win by specification and micro-adjustments. Small changes in building placement, swale geometry, and planting can create measurable uplift. Think in terms of units per £: where can a single tweak deliver the most?
At this stage, bring sales into the conversation; biodiverse landscapes are not only compliant, but they can also be amenities with real marketing value.
Secure off-site units before you even consider credits: Scan the local market for providers with the habitat types you need and credible delivery and monitoring capacity. Align procurement with programme: some habitats have longer establishment times, and you want your legal agreements and phasing to match decision timelines and cashflow.
Keep statutory BNG credits as contingency: If there is still a gap, document why on-site/off-site cannot cover it and quantify the smallest credit purchase that removes planning risk without overpaying. The pricing is intentionally premium; treat credits as a bridge, not the plan.
Lock in 30-year governance: Your plan must be secured through a legal route – s106 or conservation covenant – with a funded habitat management and monitoring plan. Decide who carries the obligation, how monitoring reports will flow, and how costs will be managed over the long term. Getting this clear up front will pay dividends at validation and committee.
The LVA Method™: a developer’s BNG options model
Intelligent Land’s Land Value Accelerator™ (LVA Method™) exists to make those choices explicit and commercial.
- Review Planning Permissions. We start with the current planning status and the ecological baseline, stress-testing red-line assumptions, irreplaceables, and any local policy nuances. The goal is to identify where BNG is affecting viability and where the quick wins may be hiding. Getting the baseline right avoids design churn later.
- Undertake Research. We pull the latest statutory metric guidance, small-sites rules when relevant, and map the landscape of off-site unit providers in your geography. We also price statutory credit bands so you have a true ceiling. On the legal side, we compare the pros and cons of s106 and conservation covenants for your specific land control, partners, and programme.
- Scenario Testing. This is where the black box works for you. Our AI-driven engine runs design permutations (edges, buffers, SuDS planting, roofs, management specifications) and procurement mixes (off-site units from multiple providers, different phasing, and delivery risk profiles). Each scenario is scored in £ per unit, impact on NIA and GDV, and weeks to consent. The result is brutally clear: one pathway emerges as the cheapest compliant route, with a backup if anything changes.
In many cases, our approach above surfaces a £1m+ value uplift within 24 hours, simply by reframing BNG as a set of options instead of a fixed tax.
Worked example (illustrative) relating to biodiversity net gain for developers
Take a 220-home scheme on 11.5 hectares at the settlement edge. The first pass of the metric, run after a late design freeze, showed a 14.3-unit shortfall. The design team proposed enlarging a central park, dropping two plots to close the gap.
LVA went back to the baseline, re-spec’d SuDS basins and street tree mixes to lift habitat condition targets, and added biodiversity roofs on around forty percent of garages.
Those specification changes alone delivered roughly eight additional units with minimal capex and no loss of NIA.
The remaining shortfall was covered by off-site units purchased from a local habitat bank within catchment, with a modest two-unit credit contingency held in the budget for risk. The scheme hit 10%+, avoided plot loss, and produced a cleaner officer report narrative with a governance pack ready to go.
Development programme intact; margin protected.
BNG guidance for developers: governance mistakes to avoid
A handful of errors show up repeatedly. The first is late baseline work. If you run the statutory metric after you’ve fallen in love with a layout, you’ll invite redesign, and redesign invites credits.
The second is type mismatch when shopping for off-site units; units are not fully fungible, and policy expects alignment on habitat types and geography.
Third, teams under-play the 30-year reality. Management and monitoring need a named owner and a funded plan, or conditions will drag on. Finally, beware the idea that credits are always quicker. They can be, but they are priced to discourage overuse, and heavy reliance can weaken your position at committee. Getting these four points right transforms BNG from obstacle to enabler.
BNG advice for developers: practical playbook
Treat ecology as a commercial meeting, not a siloed discipline.
Put metric outputs next to £/unit and NIA so planning, design, and finance are making the same decision.
Tie BNG design choices back to sales: richer planting and visible nature can elevate the place story, support price points and improve absorption.
When you model options, think “good, better, best”: a design-led on-site heavy approach; a balanced route with off-site units; and a minimal-credit contingency.
Take your LPA with you and share the shape of your plan, your preferred legal route, and the monitoring responsibilities early so validation is smooth and officers aren’t surprised late in the day.
Keep an eye on policy tweaks, especially for small sites and exemptions; small changes can alter procurement timing and the economics of units.
Frequently asked (by delivery teams)
- Why can’t we just pay for BNG credits and move on? Because policy is designed to make credits a last resort and more expensive than market units. You’ll typically clear compliance more cheaply with a blend of on-site optimisation and off-site procurement, and you’ll look better in officer reports and at committee. Credits are a contingency, not a default strategy.
- Do we really need a 30-year plan if we buy off-site BNG units? Yes. Off-site providers carry the same 30-year management and monitoring obligations through a legal agreement. If you control the off-site land yourself, the obligation sits with you or your chosen responsible body. Either way, it has to be specified, funded and monitored.
- What about small sites? Small development sites are within scope once they meet the thresholds. The Small Sites Metric simplifies calculation, but you still need a reliable baseline and a plan to deliver and maintain uplift. The same sequencing -baseline, smart on-site design, off-site procurement, credit contingency, legal lock-in – applies, just at a tighter scale.
How Intelligent Land helps (fast)
BNG for developers is new and it’s a cost so affects viability of the value of land and selling it, so the LVA method can help mitigate viability and cost impact. BNG can de-rail a project so LVA could help. If the impact of BNG requirements is blocking your scheme, then LVA can help to unblock it as it can reveal hidden land value.
That’s the brief we work to.
We begin with rapid baseline truthing, checking the metric inputs and red-line assumptions that often cause the biggest shortfalls. We move into value-led design, where we target the most efficient unit gains per pound – often specification changes that avoid NIA loss.
In parallel, we run a market scan to source off-site units before you drift into credits and we quantify any genuinely necessary credit premium so the board can see the real trade-off. Finally, we package the governance – the legal route (s106 or conservation covenant), a funded Habitat Management & Monitoring Plan, and a pragmatic reporting cadence, so conditions don’t drag your programme.
Land Value Accelerator™ – Unlocking Hidden Millions.
A solid plan starts with an executive summary that sets out your baseline units, the required uplift, and the chosen route (on-site/off-site/credits mix). It should include the metric workbook, signed off by your assessor, and a coherent on-site design schedule that specifies habitats, target conditions, and management standards with drawings to match.
If you’re buying BNG units, add an off-site procurement pack that names the supplier, habitat types, unit counts and phasing, and outlines delivery risk and how monitoring will be evidenced. If there’s still a small gap, include a credit contingency with a clear justification narrative and budget allowance.
Finally, attach the 30-year governance: draft s106 or covenant clauses, a costed HMMP, and the monitoring plan with roles, cadence and triggers.
Final word
BNG isn’t a tax on development, instead reframe it as a constraint that hides cash when you treat it as an options model. If your spreadsheet says BNG wipes out plots, forces premium credits, or extends programme, you don’t have to accept the first answer. Re-run the baseline, retune the specification, scan the off-site market, and reserve credits for the smallest residual gap.
BNG is new and it’s a cost so affects viability of the value of land and selling it, so the LVA method can help mitigate viability and cost impact. BNG can de-rail a project so LVA could help. If the impact of BNG requirements is blocking your scheme then LVA can help to unblock it as it can reveal hidden land value.
Next step: Book an LVA BNG Value Scan. In 24 hours, we’ll show you three compliant pathways, the cheapest per unit, and the effect on NIA, GDV and programme – so you can unlock hidden land value and consent without burning margin.
