Balancing your development losses
Mike Hopkins MCInstCES, Managing Director, Storm Geomatics
Many levels of leadership in our 21st century economy are turning towards a regenerative period where humanity must put back what it has taken away.
This is because there is an overshoot of negative impacts from earlier economic models that has put the planet into a degenerative and unsustainable position, which needs addressing at once before the situation is irrecoverable.
Biodiversity Net Gain (BNG) ensures that all developments have a measurably positive impact on biodiversity compared to the pre-development state. As a result of the Environment Act 2021 it is now law in England for major and minor building developments to replace 110% of the biodiversity losses that they cause.
This will also come into force for ‘nationally significant infrastructure projects’ from late November 2025.
The system that implements this is Biodiversity Net Gain (BNG) which ensures that all developments have a measurably positive impact on biodiversity compared to the pre-development state.
Developments will not be able to start until this mandatory planning condition has been discharged.
There is no getting away from this.
To discharge this planning condition developers are engaging with environmental professionals that evaluate individual land parcels taking into consideration four criteria:
- Size.
- Condition.
- Strategic location.
- Type.
Early stage optioneering from environmental professionals will inform developers on the best strategic approach to the BNG law for their individual site, this first desktop evaluation is low cost but is essential to make the best decisions on the possibilities for the site.
Environmental professionals are partnering with geospatial surveyors to capture BNG metric-sensitive measurements which makes certain that the most cost-effective options are available for the developers/investors.
If the investor decides to go ahead with the development a full BNG assessment will be needed for the planning application to be approved.
A site visit from a competent person is conducted to capture correct data concerning the above criteria, which is then entered into the DEFRA Statutory Biodiversity Metric to return a value expressed in biodiversity units (BU).
Environmental professionals are partnering with geospatial surveyors to capture BNG metric-sensitive measurements which makes certain that the most cost-effective options are available for the developers/ investors.
The measurement part of the BNG metric is interesting for the geospatial profession as it is sensitive to the geometry of the varying habitats within a site. Investors and developers will be paying between £25k- £240k for one biodiversity unit, depending on the habitat type, so the geometry input can influence the final BNG cost to the developer significantly.
Once the baseline biodiversity value (in BU) of the site is proven, the same metric is used to predict the post-development value, which is achieved using design drawings to calculate areas of habitat loss/ gain.
The residual value in BU from predevelopment minus post-development must be made up +10% and accounted for in a s106 legal agreement before development starts, the creation of biodiversity units can be done onsite or offsite.
Does the BNG system work?
In theory, yes. In practice, time will tell. My experience with BNG is two-fold, firstly I have passed a river condition assessment (RCA) course, which is necessary to complete a river/watercourse BNG calculation, and secondly, I co-own and manage a 14-acre BNG offset site – Halford Flood Meadow – which is a species rich floodplain with a mosaic of habitats – in the making.
By going on the RCA course, I have expanded my knowledge in natural river processes which has given me an addiction to understanding the amazing interconnectivity of ecosystems.
By owning and managing a 14-acre BNG offset site has emptied my pockets and made me realise how difficult it is to force nature. In turn, this has made me realise the value of the biodiversity losses that have arisen through construction.
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When I embarked on my floodplain restoration project to establish a species rich meadow of neutral semi-improved grassland distinction, the county ecologist said I would be doing well to get to a ‘medium’ condition in 30 years of managing the meadow. Imagine how long it takes to establish a species rich meadow in ‘good’ condition!
BNG is forcing the construction industry to understand how important biodiversity is to sustain a healthy ecosystem for humans and I am convinced that when our attention is drawn to this, as human beings we will all embrace it.
Through construction and modern weedkillers, we can destroy an incredibly biodiverse habitat in one afternoon that could have taken 100-plus years to establish. Much of the population do not realise the significance of that – I must admit that I didn’t until I started to get involved with BNG.
When I think of it like this, I realise how both sensitive and hardy these vitally important habitats are, sensitive because it is easy for humans to destroy them, and hardy because they regenerate naturally and tolerate all but the most catastrophic circumstances – human intervention.
It is extremely difficult to convey the message of sustainability and biodiversity to the construction industry, is this because it is almost the exact opposite of what the industry is trying to achieve and is therefore ignored and almost treated as a nuisance?
BNG is forcing the construction industry to understand how important biodiversity is to sustain a healthy ecosystem for humans and I am convinced that when our attention is drawn to this, as human beings we will all embrace it.
For now, I need to get back and tend to my meadow which has flooded 12 times since I sowed an expensive flood meadow seed mix in September 2023. My ecologist told me last week that I have lost nearly all the seed in the floods and the exercise has so far been a failure – a perfect example of how climate change is supressing biodiversity and a warning that we are approaching a point of no return.
To understand more, please Google ‘biodiversity’, it is a fascinating subject.
Mike Hopkins MCInstCES, Managing Director, Storm Geomatics
mike.hopkins@storm-geomatics.com