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16th October 2023

Free tool: How to calculate Biodiversity Net Gain monitoring charges

Verna publishes Excel calculator to help Local Planning Authorities mitigate the financial risks of monitoring BNG.

Many Local Planning Authorities (LPAs) have asked us about how they should charge planning applicants for the 30-year monitoring activities required by Biodiversity Net Gain (BNG) legislation. To help with this, we have created a free Excel calculator which we hope will support LPAs’ internal decision-making.

This tool is based on learnings from discussions with and between LPAs, and in particular the community of users of Verna’s Mycelia software. Mycelia gives LPA teams an end-to-end BNG solution – providing support from validation and assessment, to monitoring and reporting.

Others have done good work on monitoring fees too, including Buckinghamshire Council whose calculator can be found, for those with access, on the Planning Advisory Service forum for BNG practitioners at LPAs. A direct link to the Buckinghamshire calculator on the forum is here.

The context for BNG monitoring fees

As we have written about previously (e.g. on the CIEEM website), effective monitoring is essential for the successful implementation of BNG.

LPAs can charge planning applicants to cover costs associated with this monitoring. The mechanism for this has been outlined by Pinsent Masons: “CIL regulations confirm that a local planning authority may lawfully include a monitoring fee as a planning obligation if it is fairly and reasonably related in scale and kind to the development and does not exceed the local authority’s estimate of its cost of monitoring the development over the lifetime of the related planning obligations”. This is typically achieved through a Section 106 agreement.

We are aware that some LPAs are either not charging applicants or are at risk of under-charging them. One reason for this is that LPAs may not be fully considering how the value of money decreases over time – assuming an inflation rate of 5%, an activity that costs you £100 today would cost you £432 in 30 years’ time. So you need to charge enough now to cover those greater costs further down the line.

Consequently, there is a risk that LPAs may be locking themselves into a deficit – with each additional monitoring site eating into core budgets.

Verna’s monitoring fee calculator

Of course, there is a lot of uncertainty about how much things will cost in the future, so there are a range of assumptions LPAs could make about how much they should charge for monitoring a particular case. These assumptions might include the number of LPA colleagues that need to be involved, the time required from each colleague, and how this differs between reporting and non-reporting years.

To help LPAs estimate what they should charge for monitoring a case, and to provide an evidence base to help counter any challenge, we have developed a Monitoring Fee Calculator tool. It takes into account the cost to the LPA in both reporting and non-reporting years, and translates costs in future years into the value of today’s money. The calculator assumes that the monitoring fee is received in a single upfront payment. In addition to habitat monitoring, some LPAs might also choose to charge for assessing the management plan and reviewing updates to this plan; the tool includes the ability to account for this.

You can download the Monitoring Fee Calculator here (Excel file, no macros).

For guidance on how to use the tool:

When inputting assumptions for a particular case, you could consider the approach taken by Buckinghamshire Council and consider factors such as the size of the biodiversity gain site(s) and the technical difficulty of the proposed interventions.

We recommend that LPAs act prudently by charging more, rather than less, to ensure their costs are covered (within the constraints of what is ‘fair and reasonable’).

Please note that we are sharing this tool simply to provide input to LPAs’ thinking. The ultimate decisions on charges to applicants of course lie with LPAs. Please feel free to share this tool freely, as food for thought – we don’t provide any guarantees related to it, or accept any liability for decisions informed by its results.