The Cost of Overlooking Biodiversity in Planning
For property developers, navigating the planning system has never been more complex—or more dependent on ecological compliance. With the introduction of mandatory Biodiversity Net Gain (BNG) under the Environment Act, biodiversity has moved from a secondary consideration to a legal requirement. Understanding how biodiversity consultancy prevents costly planning delays is now essential knowledge for anyone involved in development projects.
BNG is no longer just a box to tick at the end of the planning process; it is an integrated part of how planning permissions are granted. Local planning authorities expect developers to demonstrate how their projects will not only minimise environmental harm but also deliver net gain in biodiversity. This means working with ecological experts early on to ensure a viable biodiversity net gain plan is in place.
At Civity, we specialise in managing the coordination of biodiversity consultancy—though we do not carry out ecological fieldwork in-house, we ensure the right specialists are involved at the right time, helping your project stay compliant and on track.

Understanding Biodiversity Net Gain (BNG)
Biodiversity Net Gain is a planning policy requirement that mandates all new developments in England to leave the natural environment in a measurably better state than it was before. Under the mandatory biodiversity net gain regulations, developers must achieve at least a 10% calculated biodiversity net gain on their development site and/or via off-site biodiversity units.
Using the DEFRA biodiversity metric, ecologists assess the existing habitats and ecological features on-site to calculate their current biodiversity value. A biodiversity net gain assessment is then conducted, outlining how the proposed development will improve or replace these natural assets through habitat creation and biodiversity enhancements. Where on-site habitat gains aren’t feasible, the use of biodiversity offsetting at a separate site can balance the books and achieve a net gain for a project overall.
This is where the biodiversity consultancy process becomes critical. By interpreting ecological data, applying the mitigation hierarchy, and formulating a compliant BNG strategy, specialists guide the production of a viable biodiversity net gain plan. Without this input, projects risk being stalled by local planning authorities. Early consideration is key to achieving net gain and minimising cost: ensuring a minimal impact in the first place (developing land of low biodiversity value to begin with) is usually the best and easiest way to do this.
The Role of Biodiversity Consultancy in Planning Projects
A professional ecological consultancy supports developers by providing timely and accurate ecological advice tailored to the planning system. Consultants assess protected species, priority habitats, and the habitats present to inform the biodiversity gain plan. They also advise on habitat strategic significance, ensuring the plan aligns with local nature recovery strategies and is acceptable to the local authority.
One essential deliverable is the Preliminary Ecological Appraisal (PEA)—a baseline study that determines the need for further ecological surveys or mitigation measures. These early evaluations help identify constraints and opportunities for biodiversity improvements, reducing the risk of last-minute redesigns or rejections during the planning approval stage.
Another key contribution is calculating biodiversity units using the biodiversity metric, which quantifies the net change in biodiversity value before and after development. This data forms the backbone of the net gain plan and informs decisions about whether developers must purchase biodiversity credits, use habitat banks, or deliver on-site biodiversity enhancements.
Why Timing Matters: Biodiversity and the Planning System
Delays in engaging a biodiversity consultancy can have significant financial consequences. If ecological surveys are not scheduled according to seasonal availability, developers may miss critical survey windows, such as for bats or great crested newts, pushing back their planning timeline by months. For BNG assessments, sites with semi-natural habitats like grassland and woodland often specifically require a survey during the growing season (April-September) or even narrower seasonal windows to capture optimal botanical data.
By integrating biodiversity early into the land management and design phase, developers not only comply with biodiversity net gain requirements but also streamline their overall programme. A well-prepared biodiversity net gain strategy shows planners a commitment to environmental responsibility and increases the likelihood of planning permissions being granted without protracted negotiations or costly redesigns.
For instance, identifying an area of ancient woodland or discovering a protected species late in the process can result in enforced setbacks, legal challenges, or even denied planning consent. Conversely, addressing ecological factors early allows time for creative solutions that meet both conservation and commercial goals.
Off-Site Options and Biodiversity Credits
Not every development site has the capacity to support a full 10% net gain on location. In these cases, developers can achieve compliance through off-site biodiversity units or purchase biodiversity credits from approved schemes. These might include habitat banks, conservation covenants, or (as a last resort) working with Natural England to access statutory biodiversity credits.
These options must still be reflected in the biodiversity gain plan submitted with your planning application. A qualified ecological consultant will assess the viability of these routes, ensuring that any off-site solution still enhances biodiversity value and aligns with the strategic significance of local natural habitats.
The ability to boost biodiversity even when space is limited is a key advantage of a strategic, consultancy-led approach. These professionals guide developers in ensuring their contribution to reversing biodiversity loss is both measurable and meaningful.
Avoiding Delays: Biodiversity Consultancy as a Planning Partner
In many cases, developers encounter costly planning delays not because of opposition to their project, but because of inadequate or non-compliant ecological documentation. Even a well-designed site can be held up indefinitely if it lacks a clear biodiversity gain plan that meets biodiversity net gain requirements under the Environment Act.
Through professional ecological consultancy, developers gain access to expert knowledge of the planning system, local biodiversity priorities, and biodiversity net gain assessment methods. This expertise helps you demonstrate compliance with planning authorities and prevents back-and-forth delays that can derail project timelines and inflate costs.
Future Developments: Biodiversity as a Strategic Asset
In today’s environmentally conscious planning landscape, biodiversity is not just a compliance issue—it is a marker of quality and resilience in future developments. From integrating green infrastructure to enhancing natural environment assets, developers who treat biodiversity as an asset rather than a constraint are better positioned for long-term success.
Well-managed biodiversity enhancements not only improve outcomes for ecological features but also raise the attractiveness and market value of a site. Public support, improved planning approval rates, and alignment with sustainability goals all flow from a strong biodiversity net gain strategy.
In this sense, biodiversity consultancy becomes not just a way to avoid problems but a proactive partner in building places that last, adapt to climate change, and deliver measurable benefits to the community and the environment.
Invest Early to Save Later
For developers, the message is clear: the earlier you engage a biodiversity consultant, the smoother your path to planning permission. Delays, redesigns, or legal complications often arise when biodiversity net gain plans are treated as a last-minute checkbox.
A trusted ecological consultancy ensures you comply with biodiversity net gain requirements, avoid unforeseen complications, and show local authorities that your development supports the natural world. At Civity, we help you navigate the process efficiently by connecting you with specialists, managing deliverables, and ensuring your development project proceeds without unnecessary holdups.
Biodiversity is not just a regulatory requirement—it’s an investment in the long-term success and sustainability of your site. By embedding ecological thinking into every phase, you not only protect biodiversity but also futureproof your project in an evolving planning landscape.