The measures, introduced under the Environment Act, came into effect on 12 February, and will require local planning authorities to assess and seek mitigation of the expected biodiversity net gain (BNG) impact of planning proposals.

However, an ongoing survey of members of the Royal Town Planning Institute (RTPI) found that:

• 81 per cent of planners in the public sector need further ‘guidance, advice and support’;
• 68 per cent of all planners need more staff and skills, and 61 per cent require more case studies of best practice; and
• 69 per cent of planners in the private sector, whose developments and land will now need to demonstrate BNG gain as part of the planning application process, want more case studies of best practice.

The updated figures show that 41 per cent of public-sector planners still cannot confirm whether they’ll have access to the necessary ecological expertise to comply with the new BNG requirements before implementation. This is a slight improvement from September’s report, where 61 per cent of planners were uncertain.

While Department for Environment, Food and Rural Affairs (DEFRA) has confirmed funding of £10.6m for the next financial year, the RTPI has been pressing for additional resources since the proposal of these new requirements, as it’s uncertain whether the allocated funding will be adequate.

Victoria Hills, RTPI chief executive, said: “We made it clear to the Government that, without adequate funding, new BNG requirements could add disruption and delays in already overstretched local planning authorities. While we welcome the additional resources from DEFRA, we feel that only time will tell whether this funding will be enough.

“However, planners in the public and private sectors are still calling out for guidance, advice, and support to help them improve the biodiversity of new development.”

The latest results from the RTPI’s Biodiversity Net Gain survey were collected between September 2023 and January 2024. To help the Institute monitor changing levels of understanding, the survey does not have a closing date. If planners’ level of knowledge and training significantly changes over time, the RTPI encourages them to complete the survey again. 

For a deeper dive into the new measures, the Local Government Association’s Planning Advisory Service (PAS) has been producing resources to help support local authorities.

The Home Builders Federation (HBF) said the aim of the BNG mandate aligns with home builders’ efforts to protect and enhance natural environments, but it cautioned that the impact on an already complex planning system should not be overlooked. It pointed out that delays in securing planning consent are already considered a significant barrier to the delivery of homes – with 93 per cent of SME home builders identifying planning delays as a major barrier to growth, according to its own research with Close Brothers Property Finance and Travis Perkins.

Sam Stafford, HBF planning director, said: “Biodiversity net gain is already being achieved on developments across the country, delivering significant benefits to residents and the environment. However, operational challenges must not be underestimated. Ensuring there are viable options available, particularly for small sites, is vital, and expectations must be managed as this new way of working beds in.

“While the developers of larger sites have been increasingly including BNG on their developments, for smaller sites, where it’s not possible to deliver on-site solutions, there is a reliance on off-site credits – the availability of which is a challenge in some areas, with the market still in its infancy.

“We also need to ensure there is sufficient capacity in local authority planning departments to manage biodiversity net gain. Delays in the planning process are already a major constraint on development. BNG adds further complexity to the process and without adequate resourcing, further delays are inevitable.