Highlights from the NACF industry webinar – Biodiversity Net Gain: the practicalities, challenges and opportunities

Biodiversity net gain (BNG) is the newest and perhaps least understood of the new regulations and requirements of public sector construction. It presents us with considerable challenges in assembling teams with the correct balance of skills, aligning professional opinions between client, contractor and planning authority, and understanding the ongoing governance of biodiversity.

To tackle these issues and more we brought together a brilliant and diverse panel for a webinar discussion to look at some key lessons and learnings from some of the first schemes. Our panel also shared their thoughts on navigating the shift in our culture and approach to growth in public sector construction that BNG needs.

Our panel featured:

Neil Sherriff, Senior Sustainability Manager, Mace Group

Sam Bower, Head of Sustainability: Ecology, Biodiversity, Arboriculture, Balfour Beatty

Adam Sanford, Operations Lead, SCF Frameworks

Rory Watson Newman, Estates Contract Manager, One Horton Heath

Rachel Jones, Principal Consultant – Planning Advisory Service and ecology manager, Wiltshire Council

We were very pleased to welcome 135 attendees joined from a diverse audience of Environmental Specialists and Ecologists to Project Managers and Engineers. The breadth of interest was a reflection of the reach of skills and expertise needed in meeting BNG requirements.

In this article, we’ve picked out some of the key pieces of insight from the discussion to share. We hope that some of these will help our construction and public sector colleagues to start on the right road with BNG.

Getting the right team in place

Adam – Start out by having early and informal discussions, so that you can build the right team at the right stage in the project. This means bringing in-house resources together with consultants and supply chain construction partners and encourage engagement and conversation early before making too much progress. Don’t be reserved in tapping into your longer-term relationships and make use of collective expertise and experience.

Neil – We’ve been delivering 10% biodiversity Net gain for the Ministry of Justice since November 2020 and it was very clear from the outset that you needthe right team of technical consultants in place. The ecology consultants are now having to wear two hats of 1. delivering the ecology surveys and 2. the BNG assessment and delivery.

You also need to engage a landscape architect alongside your project architect from RIBA stage 1, where previously they would step in at RIBA Stage 3. The ecologists working with the landscape architect and architect need to be running the BNG assessment at concept design stage on site layout options to gauge how far out or not you are on BNG early on.

Rachel: My experience is that every planning authority is different. Some like Wiltshire are lucky enough to have an ecology team, others outsource and then some just don’t have any resource at all. As a result, you’ve got a complete spectrum of different approaches that need to be taken into account. Different resources and people with differing levels of expertise will be looking through these documents and so it’s important that they are clear and concise. Many local authorities don’t feel very prepared as yet for BNG and there’s an awful lot of guidance that’s still to come from government.

Rory: Focus your team on getting to the baseline and ensure the developer maintains it, but make sure you have a team with the skills to understand the complexities of the short and long-term management and maintenance plans. Simplify the plans where you can and provide a schedule that anyone can understand.

Sam: We’re coming at the project as a principal contractor so in that context it is fundamental to make sure that you have the expertise integrated across the team. You need biodiversity guidance and input at all stages of the actual delivery process across disciplines. It used to be that the ecologist was just involved at site clearance and towards the end with landscaping. With BNG, they now need to be involved in areas such as drainage, site management, earthworks, soil management, vegetation clearance etc right across the duration of the project.

Aligning clients and contractors and developers

Rachel – As a local planning authority we’re reviewing planning applications, looking at the different stages and then towards monitoring and reporting. We’ve been considering in detail on-site versus off-site provision and strategic approaches. I’ve been looking at our own land holding to assess recreational areas as well as rural estate.

Adam – I think it’s really vital to get that expertise baked into the whole team and to include BNG as part of their stakeholder engagement, such as early consultation stages with local communities. Bear in mind that your supply chain might not carry the experience or expertise but that local community will be able to network within itself so there might be other suppliers in the area.

We’ve had some major challenges with nutrient contamination in the solent and had to learn really fast to look at the development in line with the public need in the area. It’s been vital not only to have that network of close relationships with supply chain but also being able to network within other public bodies in the area.

Neil: It is important to remember that BNG does not absolve the developers of their responsibilities to ensure appropriate species mitigation is undertaken for the development and- it is embedded throughout the BNG process. We’ve learned the hard way that the actual BNG % figure/target should not be fixed with the LPAs at planning stages but worded in the conditions more generally that the Project will deliver BNG .The design will evolve at RIBA Stage 4 as the design is worked up in detail and this can potentially impact on the BNG figure and so we would recommend aiming for a float of a t least +15-20%BNG at outline For example, a subcontractor could come along at RIBA Stage 3/4/5 and request space to set up a logistics area or there is a design change and that can upset the BNG figure thereby reducing it down. So my advice is that the clients, contractors and developers all work together to agree a float from the outset and to try and anticipate where the fluctuations might arise so the +10% BNG target is reached .

Sam: As a collective team, recognise that BNG is a core component against which project success is measured (and legally authorised) – in the same way that safety has become and carbon and sustainability goals are moving towards. You’re seeing it in design, in tenders and contract, in every component of delivery and in the long-term aftercare/maintenance period.

Rory: Add consultants to the mix to work across the broader team and establish baselines. Address it together by looking at phases. On a 10 year project for example can you work together to identify pockets you can deliver earlier?

On-site challenges and learnings

Sam – Make sure that the design has been robustly challenged and assessed to take details into account. For example, the level of detail for soils analysis or other environmental factors which may affect those habitats. A good example is in building roads where the amounts of particulates coming off the carriage may have an adverse impact on different floral communities.

Like any kind of infrastructure, you need to start with the fundamental foundational component which is your soil and get that absolutely right. That requires more planning and more consideration with BNG and often more space which can impact viability on many schemes.

Neil – We are all certainly having to accept that there are some interesting practicalities to watch out for. We are having to make sure that logistics are much tighter so that we are more mindful of BNG and maintaining that baseline assessment with site set up on some of these long-term projects.

Sustaining BNG for the long-term

Rory – Plans for ongoing maintenance should be fully costed from the outset and a value set against it. There needs to be sufficient funds available. It is also useful to think beyond legal obligations in terms of engaging communities to support the benefits it can bring. Beyond meeting targets, appreciate the wider benefits and what else a development delivers for a community in terms of health, active travel, attracting investment etc, so BNG is considered as an asset rather than a cost burden.

The trickier area is around banking BNG and offsetting and one of the answers is to make them relevant to where the development is located so that there is an immediate benefit to the local community. We should be looking within parameters to ensure any offsetting is delivered within a reasonable distance.

Neil – I have come across housing schemes where they’re trying to get the local community who are living in them to get involved in long-term management but BNG landscapes can be quite complex to maintain and unless the residents have the skills and intend to stay long-term there is a risk to this approach of the BNG landscapes failing over time

Sam – Ultimately, it’s going to sit with the asset owner be that a developer, statutory body, local Authority. Either way, they will be incorporating these commitments into their business model. For independent developers, it’s a massive challenge in the ownership of the asset and how that that is reflected in that cost and associated commitment.

Some of the benefits can be costed such as nutrient harnessing and air quality improvements, but others like well-being and the mental health value of being in green spaces are harder to quantify. As an industry, we need to remember why it is that we’re doing it and that the costs come with enormous benefits.

Rachel – The resourcing element is not something that’s been a statutory function for local authorities but it is something that everyone is having to think about. Somebody needs to be monitoring and checking and able to action any enforcement. We’re looking at how we can self-resource at the moment.

BNG over the long-term will work well if everyone is being precautionary and realistic, so it doesn’t just become a numbers game. There are already high expectations and over estimations about what can be delivered on site and we have to be realistic if we are going to get good outcomes.

Adam – It’s important to think about long-term BNG and where it fits alongside social value and public access, both mature legislation having been around for 10 plus years. It’s really important to see where both environmental and social value legislation can complement each other. Community benefits come from having a more diverse and nature-friendly environment, the improved immunity of a site that has been built to complement its environment. It’s really important to make sure that when social value is being considered that there are also opportunities within biodiversity to upskill local communities and use this biodiversity work as opportunities for education and employment.

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