Biodiversity Net Gain (BNG) is now a formal requirement

Designing Biodiversity Net Gain Together: An Architect–Ecologist Perspective

As architects and ecologists, we increasingly find ourselves working side by side from the earliest stages of a project. Biodiversity Net Gain (BNG) has changed how development is planned in England, but more importantly, it has changed how disciplines need to collaborate. When ecology and design are aligned from the outset, BNG becomes less about mitigation and more about shaping better, more resilient places.

Our experience shows that projects are strongest when biodiversity is treated as a shared design responsibility rather than a late-stage technical check.

Starting with Evidence, Not Assumptions

Every site tells a story. Ecological surveys provide the baseline data that establishes habitat types, condition and ecological value, using recognised classifications such as UKHab. For architects, this information is not a constraint but a critical design input.

By reviewing ecological findings together at the start of a project, we can identify where higher-value habitats should be retained, where enhancement is most effective, and where development pressure can be absorbed with the least ecological impact. This early, research-led understanding allows site layouts to respond intelligently to existing conditions rather than retrofitting biodiversity into leftover spaces.

BNG as a Shared Design Parameter

Too often, BNG is addressed once key decisions are already fixed. At that point, options are limited and projects can become reliant on off-site biodiversity units or statutory credits. When architects and ecologists collaborate during early concept design, the mitigation hierarchy can be applied meaningfully: avoid harm first, minimise impacts second, and enhance biodiversity through design.

This approach allows biodiversity gain to be planned into the scheme from the beginning, informing massing, access routes, landscape structure and open space provision. The result is a clearer, more credible BNG strategy that aligns with the brief, budget and programme, rather than working against them.

Translating Ecology into Buildable Design

Ecological recommendations only succeed if they can be delivered on site. Landscape and architectural design play a crucial role in translating survey data and habitat targets into spaces that are functional, attractive and measurable within the biodiversity metric.

Working together, architects and ecologists can select planting typologies, surface treatments and management regimes that are both ecologically meaningful and compatible with the wider design. Because the metric relies on specific habitat classifications, this collaboration ensures that what is designed can be confidently counted and maintained over time.

This shared understanding reduces the risk of mismatch between ecological intent and constructed reality.

Designing Through Change

Design is rarely linear. As schemes evolve, building footprints shift, servicing requirements change and densities are refined. These changes can have a direct impact on biodiversity calculations.

An integrated architect–ecologist workflow allows BNG implications to be tested iteratively as the design develops. Options can be modelled, trade-offs visualised, and decisions guided toward solutions that maintain or improve biodiversity outcomes without undermining architectural quality or project viability.

In urban contexts, where additional tools such as the Urban Greening Factor may apply, this collaborative approach helps reconcile multiple policy requirements into a coherent design response.

From Strategy to Construction

BNG does not end at planning approval. Delivering measurable biodiversity gain requires continued coordination through technical design and construction.

This includes agreeing substrates and soil depths, designing green roofs and walls, coordinating drainage and irrigation, and ensuring that habitat features are buildable and durable. By maintaining collaboration between architects, ecologists and landscape specialists, biodiversity intent is carried through into specifications and construction information, reducing the risk of value being lost on site.

Long-term management and maintenance considerations are also embedded early, supporting habitats that thrive beyond practical completion.

Why Early Collaboration Matters

When biodiversity is considered late, costs rise and opportunities shrink. Early collaboration between architects and ecologists reduces reliance on off-site solutions, strengthens planning submissions and creates places that perform better environmentally and socially.

BNG is now a permanent part of the planning landscape. The projects that succeed are those where research, ecology and design inform one another from the beginning. Working together, architects and ecologists can move beyond compliance and use BNG as a catalyst for thoughtful, place-led development.