In environmental law, acronyms abound, and BNG aka Biodiversity Net Gain has recently been added to the list that developers must become familiar with. As of this year, BNG is a legal requisite for large-scale developers operating within the United Kingdom since February and for smaller projects starting from April.
BNG essentially mandates that any construction project must result in a quantifiable enhancement in biodiversity by at least 10%. For instance, if a building project is happening on a site featuring any ecological elements like grasslands, a water body or treeline, any destruction to those environments must be compensated in such a manner that the biodiversity increases by 10%. This starkly contrasts the past scenario when full-scale environmental destruction was permissible.
To avoid superficial attempts at conservation, termed ‘greenwashing’, the law is particularly stringent. A qualified ecologist must be appointed to accurately calculate the “units of biodiversity” lost and subsequently gained. Tools have been devised to evaluate the existing biodiversity and propose the corresponding level of ecological repair. Therefore, developers cannot compensate the felling of mature trees by merely planting new saplings, as the habitat provided by mature trees is not replicable by young trees.
This provision raises hopes that this might result in the safeguarding of highly beneficial ecosystems or the inclusion of existing natural features in building designs, instead of clear-cutting them to forge barren brownfield wastelands.
Whilst this law isn’t enacted in Ireland, many developers are adhering to it as if it, or a similar law, is imminent. The law has led to the establishment of a market for “biodiversity credits”, wherein landowners and farmers are remunerated for the ecological services offered by their current or newly-formed biodiversity. The aim is to achieve a better-regulated system than the less successful carbon credits market.
It will present a variety of intriguing design conundrums. What is the solution to incorporating a green rooftop and renewable power sources when your sedum flora is jostling for room with your photovoltaic modules?
This shift is also predicted to stimulate employment, specialists in meadow grasslands upkeep to ensure they stay plentiful in biodiversity and full of a variety of pollinator-attracting flora, instead of turning into monocultures with low species diversity.
Maintenance duties will also include protection of forest areas from incursion by deer, laurel or rhododendron. If BNG and other biodiversity restoration regulations are to be effective, it is vital for the system to factor in longevity. It is essential these natural habitats persist far into the future in order to have a meaningful impact.