Drone view of wildflower meadow

Onsite vs offsite BNG

Onsite vs Offsite Biodiversity Net Gain

The new Biodiversity Net Gain (BNG) planning requirement has created debate over which of the two possible delivery approaches – onsite or offsite – is most impactful. Guidance prioritises onsite, while many ecologists argue offsite will produce better long-term results. Here, we delve a little deeper to help you understand the key differences.

CONSIDER THE SCALE OF ECOLOGICAL IMPACT

One major benefit of onsite habitat creation is that it ensures gains are created where they have been lost. But because onsite provision must sit well within a development site, it will likely be usable green space with a particular amenity value, such as grassland or tree planting.

One major benefit of onsite habitat creation is that it ensures gains are created where they have been lost. However because onsite provision must sit well within a development site, it will likely be usable green space with a particular amenity value, such as grassland or tree planting.

Offsite BNG can have a higher level of ecological ambition, aiming for multi-layered, complex habitat creation. This style of habitat restoration, delivered on a larger scale, is often more ecologically viable. That’s because larger habitats often offer more scope for healthy species populations and greater resilience to damage and disturbance. All of which adds up to less risk and a more secure investment.

Caterpillar on blade of grass

THINK LONG-TERM WITH BNG RISK ANALYSIS

Onsite provision is often less ambitious and so in one sense is easier to achieve. However, due to small scale habitats and green space fragmentation it may be less viable and at higher risk of failure. Rather than being delivered and maintained by restoration experts, the onsite provision may be left in the hands of maintenance contractors or a succession of different homeowners or tenants. This may lead to degradation of the habitat delivery over time. A BNG partner with experience in and a focus on restoring ecosystems will be better positioned to take on the management and liability for the full 30-year period.

HELP THE COMMUNITY ACCESS BNG SITES

Onsite provision is of direct benefit to the occupants of any specific development, providing valuable connection with green space. While public access may not be available on all offsite BNG projects, many delivery sites – such as our own Watercress Farm – provide plentiful opportunities for community access, wildlife volunteering and nature education. So, where many homeowners benefit directly from onsite, many more local members of the community can see, touch and experience green space on offsite BNG.

Children holding moths in nature

Ultimately, everyone should have the opportunity to access green space. No matter where they live. Homeowners and renters should have access to green space within the built environment as well as more widely to parks, nature reserves, trees, and wetlands. And all of these green spaces can play a crucial role for emotional, physical, and intellectual wellbeing.

AVOID A BINARY BNG NARRATIVE

When it comes to answering the debate around onsite vs offsite, the answer is both.

Every development project is different, so think beyond whether onsite or offsite is ‘good’ or ‘bad’. Instead, think about what will most fully meet the needs of your project, nature, and the community. The UK will need both onsite and offsite provision for this legislation to be a success, which is why it’s essential that planners and developers have a comprehensive understanding of each option.

We’re working on projects to deliver nature restoration at scale, restoring biodiversity through rewilding, rewetting, peatland and woodland restoration for the benefit of climate and the community. Support our work and start your BNG journey by submitting a unit request below.