As part of the passing of the Environment Act 2021 it will soon become mandatory that developments achieve a minimum of 10% measurable gain in biodiversity, commonly referred to as Biodiversity Net Gain (BNG). The act goes on to state that the habitats must be secured for at least 30 years.
This will be a big step for biodiversity in the UK because it will mean that biodiversity will be a key consideration in all development projects. This will hopefully slow down, or ideally stop, the currently loss in biodiversity across the country that has caused the UK to be one of the most nature depleted countries in the world.
What Does This Really Mean?
This means that prior to any development commencing a Preliminary Ecological Appraisal (PEA) must be carried out to establish a baseline for the site. The PEA must include condition assessments carried out for each habitat to assess the current condition of the habitat.
The habitats can then be input into the DEFRA Metric, currently V3.1, which will give baseline habitat units, hedgerow units and river units for the site, for the site prior to the development.
The development plans for the site can then also be input into the DEFRA Metric to allow post development biodiversity units to be calculated, taking into account factors like the time that the habitats will take to achieve the condition stated.
What Happens Then?
Once the baseline figures and initial post development figures have been input into the metric an initial calculation can be carried out to establish the percentage change in biodiversity achieved by the development.
The next step of the process will depend on the figure that has been achieved. If the site already achieves at least 10% gain in biodiversity units then no further work is required, unless there is a specific requirement to achieve a figure over 10%. If the scheme does not achieve the required 10% gain in biodiversity units there are two options, the development layout can be tweaked to achieve more biodiversity units, or the units can be offset off-site.
Tweaking the development plan could include several options that would provide an increase in biodiversity units, such as increasing the amount of public green space provided by the scheme, creating hedgerows along site boundaries or setting aside areas as wildlife areas, which will allow higher value habitats to be created.
On-Site or Off-Site?
Ideally all offsetting should be carried out on-site, although this is not always possible. Typical developments will cause the loss of large areas of habitat, whatever the condition, to be replaced with roads, areas of built development or residential gardens.
Therefore, where the biodiversity units cannot be offset on-site there is the option to provide enhancements off-site, either directly through the purchase of additional land for the purpose of offsetting or through the purchase of biodiversity units from the local authority or a local scheme set up to deliver biodiversity units.
However, the units are achieved they must be secured for the required time.
What Next?
To finalise the planning application the DEFRA Metric must be completed, including details of all baseline habitats, the post development habitat creation (on-site) and any off-site habitat baseline and creation. Where off-site units are being purchased these aren’t included in the metric but will need to be outlined and secured separately to show that the scheme achieves the required net gain.
But Be Aware!
Although biodiversity offsetting should be a simple process there are common problems or misconceptions that can complicate the process, a few of these are outlined below.
Habitat creation must be realistic. There will be a temptation to show unrealistic habitats in the post development plans because that will achieve more units. However, all habitat creation will be checked by the ecologist preparing the metric and then also by the local authority ecologist. So don’t be tempted to outline football pitches as areas of lowland meadow or specify species rich hedgerows and trees in short sections in between residential gardens, doing so will just be causing yourself problems, and delays, further along the planning process.
BNG is additional to all other ecological protections and can only be considered once mitigation has been secured. Any protected species issues on the site must be dealt with outside the DEFRA Metric with the offsetting having no impact on the specific species legislation, which must still be adhered to.
Baseline figures cannot be manipulated. The baseline figures must consider the site in it’s pre-development condition. Therefore, there is no option to clear the vegetation from the site prior to the PEA being completed. If this happens there is a requirement to backdate the baseline assessment and consider the site in its natural state, which could cause habitat units to be calculated higher than they actually were, because some assumptions will have to be made regarding condition assessments etc.
And Finally
BNG shouldn’t be a chore, it should be celebrated. BNG gives the UK a chance to turn around the current biodiversity loss and to have all developments improve biodiversity, rather than reduce it. Yes, there may be a need to look at development designs and change how we look at the design of large developments, but is that really a bad thing? And yes, there are issues with the current BNG process, but any new process will go through an evolution and with improvements BNG could go on to do good things and make people consider what is being lost in the under the banner of ‘progress’.