How to prepare for biodiversity net gain requirements

Anna Cartledge is a partner and expert in planning and environment at law firm Shakespeare Martineau

From November 2023, biodiversity net gain (BNG) will become mandatory for developers in England. The legislation aims to leave the natural environment in a significantly better condition than it was found, which will require preparation from both developers and contractors to avoid unnecessary delays to planning permissions, unforeseen costs, and potential liability issues. But how can developers and contractors best prepare for this incoming legislation and will working with nature on future projects become the new normal?

“It is expected that contractors will become more heavily involved in the planning application stage, forming a joined-up team with the developer to discuss what can be delivered”

Sustainable development is high on the political agenda, with the Environment Act 2021 requiring a minimum of 10 per cent BNG for all development schemes in England. To meet these requirements, developers will need to submit a BNG plan to the local planning authority (LPA) detailing how they will achieve this on their sites. Work can only begin once these plans have been approved by the LPA.

This potential delay to development demonstrates the importance for developers and contractors to take immediate action to factor BNG into their plans, as the LPA must be confident in the plan and the ability to secure any onsite or offsite biodiversity gain, or credits that are already allocated or purchased before work can begin. There is currently a huge demand for available offsetting sites and BNG credits, and there are three common ways for developers to deliver against BNG targets.

Habitat creation

The first method is through onsite mitigation, where developers can deliver through habitat creation, enhancing BNG through measures such as landscaping and green infrastructure within the red line of the development area. This could include creating ponds and planting trees and other plants that allow the natural world to flourish alongside the development. The second is providing such mitigation offsite. This enhancement takes place on the land outside the red-line development area and can include initiatives such as having an area of land where environmental restoration has taken place.

Buying credits

The third method is through the purchase of credits, where developers and contractors contribute to largescale habitat projects that deliver high-value habitats by paying a sum of money to either the planning authority or offset provider. It is important to note that credits are meant to be used as a last resort, where BNG cannot be delivered onsite or offsite. In addition, the cost of credits is increasing, which developers may want to consider as they set out their initial plans.

If developers think they will need to purchase credits, this must be planned into the development from the start, as there are currently very limited  “off-the-shelf” credit options available. Therefore, to avoid rising credit costs and potential delays later down the line, it is important for developers to consider ways to alter their sites to provide the land required for offsetting.

Planning ahead

The preference of most planning authorities is for onsite mitigation, so developers and contractors must ensure that the outputs are delivered during the development. To do this, all parties need to be clear on the planned timescale of the build, and to bring an ecologist to the site early in the process to uncover any risks or ecological constraints. Working with an ecologist is one of the best ways to ensure that the development begins on the right foot and it is set up for success as it progresses.

While the incoming legislation could appear daunting to developers and contractors, the current National Planning Policy Framework consultation will help decision-makers clarify the government’s economic, environmental and social planning policies for improving their developments. It is also expected that contractors will become more heavily involved in the planning application stage, forming a joined-up team with the developer to discuss what can be delivered, a key point that will also be factored into the LPA’s decision to grant permission and when it will be granted.

Biodiversity net gain offers developers an opportunity to give back to the environment, so being realistic with what is being promised is extremely important as it will have to be maintained and delivered over a period of 30 years. For both developers and contractors, getting the right advice and planning as a team will help the application process run more smoothly and avoid any potential development delays.