What’s stopping us from designing for biodiversity?

After several years of measuring the embodied carbon on our projects, we’re all starting to feel reasonably confident about it. We know we need to use less, we know we need to reuse materials where we can, we know which materials have a terrible carbon footprint. All of that is, of course, a great improvement on where we were a few years ago, but embodied carbon isn’t the only measure of the impact that we have on the environment.

Over the last 50 years UK species have declined by around 20%. Globally, animal species have declined by 70% – a value high enough to be considered a “mass extinction event.” So why aren’t we talking about biodiversity loss more? And what impact do we have in the construction industry?

Some of the impacts are easy to identify; construction works often destroy habitats and can generate noise or other pollution that impacts wildlife. Within cities, we’ve identified that this is an issue and implemented schemes to try and improve the situation. In London, our green spaces and parks are protected by Historic England, and as part of the London Environment Strategy the Mayor of London has committed to making more than half of London green by 2050 – a pledge that sounds a little difficult to measure. As part of the London Plan, the “urban greening factor” was introduced for major developments. However, urban greening can be difficult to implement; on a constrained central London site, the only space available for greening is the roof – the same space where you might be considering introducing PV. If both measures help the environmental credentials of the project, which should take precedence?

Other cities have taken different approaches to improve greening. In Hamburg, there is an initiative to protect 30% of the land area as green spaces (with 10% of that being untouchable nature reserve). Because the value is based on a percentage of the area, as the city grows, so too should the green space. In addition, the initiative also dictates that if construction works impact nature, they must be compensated for elsewhere.

But these are small, local impacts. If we want to make a real difference to biodiversity, then we need to consider the wider impacts that we can have – in particular, those related to material extraction. As designers, we are rarely involved in the procurement of materials and therefore have limited knowledge of supply chains and perhaps even less knowledge of the extraction methods needed for the materials we specify every day.

Concrete production involves quarrying and dredging for sand, both of which can have significant negative impacts on habitats. Steel production also involves mining and quarrying, although a significant amount of steel is produced from recycled content. Aluminium production requires the extraction of bauxite, a process which requires removal of vegetation and topsoil, destroying habitats and leaving behind by-products such as “red mud,” a highly alkaline sludge that can result in the extinction of all life. All of which seems quite extreme for some window frames.

If we are going to consider the true impact of the work that we do, then we need to start looking beyond embodied carbon. We need to consider where the materials we use come from and whether we can specify them in a way that limits their impact on biodiversity. Using less is a great first step, but we also need to ensure that we push for greater accountability in our supply chains. We need to understand what happens beyond our construction sites and start to take that into account in our decision-making. Out of sight can no longer mean out of mind.