Lyons O'Neill

Managing a project’s environmental impact

The pandemic has taken a heavy toll on every sector and responding to it has taken an immense amount of energy and ingenuity. Yet as we navigate this global emergency we can’t afford to forget a continued crisis that has been accelerating for decades: climate change. Just like coronavirus, it’s an international emergency with far-reaching effects that needs tackling with local solutions. Although national and international action is needed, everyone has a role and responsibility to play their part. This includes engineers.

A client may come to you with pre-existing sustainability goals and certain environmental certifications they want to work towards. But even if they aren’t chasing a BREEAM rating, there’s still scope for an engineering team to build sustainability into their plans. It takes creativity and forward-thinking but engineers have an opportunity to show a client how they can manage a project’s environmental impact and think about the future of the planet.

One way to make a project more sustainable is by reducing the amount of concrete involved in its construction. Concrete is one of the most widely used construction materials on the planet but it has a big carbon footprint: it’s estimated that global cement production is responsible for 8% of the world’s carbon emissions. Minimising its use is therefore paramount but it can be difficult to move away from traditional building methods and concepts of construction.

A solution to this is in experimenting with new foundation types that allow for reduced concrete use and working with the site environment to offer structural alternatives. This was our strategy in our project for St. Nicholas SEN School, where we avoided the need for concrete-heavy large pad or deep pile foundations by designing the superstructure on top of a reinforced concrete raft slab that was placed directly on the chalk substrate. We also cut concrete use further by creating reinforced earth embankments for large retained levels in the landscape, rather than opting for traditional engineered retaining structures which are constructed with large quantities of concrete. Thinking imaginatively and working collaboratively allowed us to find new construction methods that reduced the project’s environmental footprint.

However, it’s not just the environmental impact of the construction process that must be considered. The sustainability of a project includes its lifetime impact and it’s important to manage this too. For example, drainage is a key concern and so sustainable drainage systems (SuDS) is something all engineers need to consider for their projects. Essentially, SuDS is a sequence of techniques that together form a management train to control the velocity of water flow and to remove pollutants. They offer more opportunities to reuse and redirect water than traditional drainage methods, and aim to mimic the natural process of water flow, minimising pressure on drains and the environmental disruption caused by a new structure.

The use of SuDS was another important aspect in our work at St. Nicholas SEN School. Our drainage solutions involved the installation of an attenuation tank with base infiltration to cleanse surface water of contaminants before they infiltrate the chalk below and the construction of ring and crate soakaways to manage surface water drainage and direct it towards the water table. In this way our designs help manage the new building’s environmental impact throughout its life and use.

These are just a couple of examples of the ways engineers can manage a project’s environmental impact. They aren’t prescriptive or exhaustive but they do show how creativity and careful planning can go a long way in building better buildings and more sustainable structures. The climate crisis was with us before the pandemic began and is set to be with us long after: it’s vital every sector is doing all they can.

We take our commitment to sustainable development very seriously and are proud signatories of the UK Structural Engineers Climate & Biodiversity Emergency Declaration. Find out more about the pledge and what it means and join us in signing here: