Biodiversity Net Gain (BNG) became mandatory in February 2024, with under the Town and Country Planning Act stating a development must leave biodiversity at least 10% better off than it was before the site was touched.
The BNG metric, and why a chart of numbers rarely wins planning committees or investment committees on its own.
In the last 20-years, one pattern hasn't changed: the projects that move smoothly through committee are very rarely the ones with the most rigorous spreadsheet. They're the ones where the decision-makers could actually see what they were approving.
Biodiversity Net Gain (BNG) has made that gap more visible than ever. It's a metric-driven regime, built on units, percentages and habitat parcels — and yet the thing that actually gets a scheme through planning, past objectors, and in front of investors is usually a picture.
This post sets out what BNG requires, in plain terms, and why visualisation has become a genuine commercial necessity for anyone bringing a scheme forward.
BNG In Plain English
Biodiversity Net Gain became mandatory for most developments under the Town and Country Planning Act in February 2024, with Small Sites following in April 2024.
The rule itself is simple to state: a development must leave biodiversity at least 10% better off than it was before the site was touched. What's complicated is proving it.
Proof runs through the Statutory Biodiversity Metric, which converts existing and proposed habitats into biodiversity units based on habitat type, condition, and strategic significance, using the UKHab classification system as its baseline. An ecologist establishes the pre-development baseline, models the post-development habitat mix, and the metric spits out a net change figure. If it's below 10%, the scheme doesn't have enough gain and needs more on-site habitat, off-site units, or statutory credits as a last resort — in that order, under the biodiversity gain hierarchy.
Whatever gain is achieved has to be secured for a minimum of 30 years, typically through a Section 106 agreement, a conservation covenant, or registration on a habitat bank. None of that is optional, and none of it is going away — reforms taking effect from 31 July 2026 introduce a 0.2-hectare exemption for the smallest sites and adjust the hierarchy for minor development, but the core 10% requirement and the metric itself are unchanged. Larger schemes, and BNG for Nationally Significant Infrastructure Projects from 2 November 2026, remain firmly in scope.
Where The Metric Runs Out Of Road
Here's the problem: the Biodiversity Gain Plan is a rigorous, defensible document, and it is completely unreadable to almost everyone who has to sign off on the scheme.
A planning committee member, a ward councillor, a local objector at a consultation event, an investment committee, a housebuilder's board — none of them are ecologists. Handed a metric spreadsheet showing 12.4% net gain across four habitat parcels, they have no way to judge whether that's a good outcome, a token gesture, or a scheme that's quietly sacrificed the site's best habitat to hit a number. The metric proves compliance. It does not communicate quality, and it does not build trust.
That gap is where objections form, where committees defer decisions for more information, and where good schemes lose momentum they didn't need to lose.
5 Ways CGI Visuals Clearly Show A Proposed BNG Scheme
1. Translate the metric into a place.
A habitat project labelled “G3b, moderate distinctiveness” means nothing to a resident. A visualisation showing that project as a wildflower margin along their existing footpath means everything.
2. Show change over time.
Habitat creation doesn't look finished on day one. Sequential visuals — year 1, year 5, year 15, year 30 — set honest expectations and demonstrate that the scheme has been designed for the long-term management period the legal agreement actually requires.
3. Build trust with sceptical audiences.
Objectors and committee members are far more likely to accept a scheme's ecological claims when they can see the habitat bank, the buffer planting, or the wetland creation rendered accurately against the real topography — not a stock illustration.
4. De-risk the investment case.
Funders and housebuilders underwriting a scheme want to know the BNG obligation is deliverable, not just compliant on paper. A credible visual of the habitat strategy, tied to DEFRA LiDAR data and the real site terrain, reads as a lower-risk commitment than a metric printout.
5. Work across every audience in one asset.
The same model can support a planning committee presentation, a Landscape and Visual Impact Assessment (LVIA), a Section 106 negotiation, and a public consultation exhibition — without re-briefing a different specialist each time.
Where Visualisation Fits In The Wider Approvals Picture
Visualisation doesn't replace the ecological assessment — the Ecological Impact Assessment (EcIA), the metric calculation, and the Biodiversity Gain Plan still have to be right, and they still have to be prepared by a qualified ecologist. What good visualisation does is sit alongside that evidence base and make it legible to the people who aren't ecologists but still hold the decision: planning officers weighing a Local Nature Recovery Strategy (LNRS) against a housing target, committee members under public pressure, or a board deciding whether to commit capital to a habitat bank under an Environmental Land Management (ELM) agreement.
At The Ruby Cube, we build those visuals directly from DEFRA LiDAR data and the same UKHab data the ecologist is already using, so what a committee sees on screen matches what's in the Biodiversity Gain Plan — not an artist's approximation of it. For schemes where stakeholders can't easily get to a site walk, or where a habitat bank spans hundreds of hectares, we increasingly build that as a 360° interactive VR tour or animated flyover, so a funder or planning officer can experience the mature habitat before a single seed has gone in the ground.
The Bottom Line For Developers & Project Managers
BNG is now a fixed cost of doing any development in England, and the metric that proves that this compliance isn't going anywhere. But compliance and approval are two different problems. That second problem is usually the one that determines your programme.
The metric answers the first problem. Visuals answer the second.
Bringing a BNG scheme to committee soon?
The Ruby Cube turns Biodiversity Gain Plans into visuals that planners, committees and investors can actually see — built on DEFRA LiDAR and the Statutory Biodiversity Metric your ecologist is already using.
