Here we speak with Helen Nyul, Group Head of Biodiversity at Barratt Developments about the changes coming later this year, and how the Hub is working with developers on approaching new regulations.

What is Biodiversity Net Gain and how are things changing?

Biodiversity Net Gain (BNG) is a term that is becoming more frequently used the closer we get to November 2023 and is a particular approach to development and land which deliver measurable improves to the habitat. 

In November this year, we expect the Environment Act 2021, to come into force and mandate that there must be delivery of a minimum of 10% more biodiversity in and around our developments than was there in the first place, to secure planning. 

Why is BNG becoming regulated? 

The reason for BNG being made mandatory is to try to halt and reverse the significant decline of biodiversity that we are experiencing across the UK. The State of Nature Report identifies that 40% of our native species are suffering from excessive decline. This is worrying because biodiversity is fundamental to our health and well-being as well as a strong and functioning economy . 

What steps are being taken towards BNG new regulations already? 

At Barratt, we felt confident that we could deliver the required gains. We therefore committed to achieving a minimum BNG of 10% across all development designs submitted for planning from January 2023, ahead of the November deadline. 

In the meantime, 30 of the most engaged developers have so far joined the biodiversity oversight group and recognise that this is a significant change in planning requirements and in how habitats are recorded and designed in all new developments. The purpose of this group is to support the homebuilding sector in successfully complying with the BNG requirement in a cost effective manner, securing positive outcomes for nature and creating better places for local communities. It provides a space for companies to share experiences and challenges and find common solutions. 

Defra, Natural England and others have provided a wealth of guidance associated with the process of delivering BNG. However, the terms and processes are still not well understood or defined in regulatory terms. We await the release of the secondary legislation to firm up some of that understanding, which is expected early in 2023.

What have the BNG Oversight group been working on so far?

In the first meeting of the group, there was much discussion around the clarity needed for terms and processes, most notably from our colleagues who operate small to medium sized enterprises (SMEs). SMEs are an important part of the building sector and can be disproportionally affected by new legal requirements. If we are going to reverse the trend in biodiversity loss as well as support our SME housebuilders, then they need to be as engaged with the BNG process as the large housebuilders. 

One of the first issues highlighted was the language and terminology associated with BNG. A process designed by ecologists to be used by other ecologists was never going to be easily accessible by non-ecologists. A challenge, of the main target group for the delivery of BNG requirements are developers. Therefore, we have developed a short glossary of terms to try and explain some of the terminology used below.

Mitigation hierarchy

An example to begin with is the ‘mitigation hierarchy’, a fundamental principle associated with the design of BNG projects. It is a term that describes a process that has been used in conservation management for over a century and formed the basis for environmentalism in the United States in the early 1900s. Today’s mitigation hierarchy process requires the developer to ‘avoid’, ‘minimise’, ‘mitigate’ and then finally ‘offset’ their impact to biodiversity through the design of their development. However, that in and of itself is not an explanation to non-environmentalists. The whole principle really needs to be unpacked and translated into language understood by developers in order for it to be properly implemented from site identification to the design process. 

Good practice principles

The mitigation hierarchy is just one of the 10 BNG Good Practice Principles that are often overlooked or misunderstood. The principles are needed to ensure the process is adhered to correctly and that the best outcomes for biodiversity are achieved. Most ecologists have a good understanding of these and how they should be applied. Although a number of these principles are captured within the Biodiversity Metric calculator (see below), for an SME without any ecology capacity they could be designing BNG projects that miss or disregard some of these principles, potentially leading to time consuming re-plans and additional costs. 

Habitats versus species

Another area that often causes confusion within the sector is the fact that the process only measures the impacts associated with habitats and not species. This decision was based on the fact that a healthy and functioning habitat should provide shelter, food and places to breed for the species associated with those habitats. Thereby the habitats act as proxies for species. A fact well understood to an ecologist but not so well understood to a developer who is wondering why the hundreds of bird boxes installed around their site do not count for anything in a BNG calculation.

Biodiversity Metric

Then there is the calculator itself, the Biodiversity Metric. A simple tool on the face of it, which can be easily downloaded from Natural England’s website and filled in by a non-ecologist with limited training. However, to ensure accuracy, both in terms of the data input and interpretation of the results, this requires an experienced ecologist. Without this input, erroneous biodiversity baselines and wildly ambitious net gain scores are commonplace. However, how does a developer, particularly one with limited internal capacity such as an SME, engage with the calculator to provide optimal outcomes, both for biodiversity and the developer? This is also necessary to avoid SMEs having to continually reassess their BNG score with external consultants, thereby costing money as they go through the design process. 

Biodiversity units and credits

Another area of confusion are the terms ‘biodiversity unit’ and ‘biodiversity credit’ and their association with a biodiversity offset, which is the last step on the mitigation hierarchy. A biodiversity unit is both a measure of biodiversity used in the Biodiversity Metric and a tradable item generated through a habitat creation or enhancement project. Whereas a biodiversity credit is created by the Secretary of State, which a developer can purchase as a last resort, when no other appropriate offset options are available. The funds are then invested in habitat projects across the UK. The issue with this is that the terms are often used interchangeably even within the ecology sector. 

Biodiversity offset

We have found the term ‘biodiversity offset’ to be another major source of ambiguity. From an ecological perspective an offset needs to be the action of last resort, a well-considered activity that provides meaningful mitigation in proximity to the site of impact. These criteria are to some extent captured in the Biodiversity Metric (scores are weighted positively or negatively depending on the offset). However, the rationale behind the criteria needs to be defined in a way that helps a developer make decisions as to whether or not there is an appropriate offset nearby that will provide an optimal outcome. 

Benefit stacking

Also associated with offsets is the term ‘stacking of benefits’. This allows for more than one environmental benefit to be produced and sold from the same area of land, an important consideration in areas that are restricted in terms of land availability. Without understanding this concept or how to deliver and segregate the benefits, offsets could be created that miss opportunities for wider environmental benefits or make claims about stacking that cannot be demonstrated or delivered appropriately.

Next steps

The above list of terms is not exhaustive and most of these are associated with the first steps associated with site identification and design of a BNG compliant development. There are still lots of terms associated with delivery, management and long term maintenance that need to be translated. 

This is why the next step for the Future Homes Hub BNG Oversight Group is to produce SME specific guidance, in language that does not water down the BNG process, but provides clear and unequivocal terms that support SME housebuilders meet their requirements. The BNG requirement needs to be understood by SMEs and, like larger businesses, they need to engage with the process appropriately. This will hopefully mean that more businesses are geared up to meet the November 2023 deadline. 

Find out more about the Biodiversity Net Gain Project

References

[1] Hayhow DB, Eaton MA, Stanbury AJ, Burns F, Kirby WB, Bailey N, Beckmann B, Bedford J, Boersch-Supan PH, Coomber F, Dennis EB, Dolman SJ, Dunn E, Hall J, Harrower C, Hatfield JH, Hawley J, Haysom K, Hughes J, Johns DG, Mathews F, McQuatters-Gollop A, Noble DG, Outhwaite CL, Pearce-Higgins JW, Pescott OL, Powney GD and Symes N (2019) The State of Nature 2019. The State of Nature partnership.

[1] Dasgupta, P. (2021), The Economics of Biodiversity: The Dasgupta Review.