Achieving net zero goals in construction and design requires further regulation that must focus on both operational energy efficiency and embodied carbon, argues Thornton Tomasetti’s Sustainability Lead Duncan Cox.
Published in Global Construction, December 6, 2019
This year we have seen a huge rise in political, public and industry attention toward climate change, with the global emergency dominating many of the headlines. As a result, the UK government committed to becoming net-zero by 2050. But what does this mean for the construction industry?
Following the net-zero targets announced by the government, the UK Green Building Council (UKGBC) released a framework definition for net-zero carbon buildings to provide the industry with clarity on how to achieve net-zero carbon in construction and operation. The building sector currently contributes to approximately 40% of global greenhouse gas emissions (source AIA2030) highlighting the crucial role our sector must play in targeting net-zero carbon.
More recently, structural engineers and architects across the UK have declared a climate and biodiversity emergency, with firms across the country committing to strengthen working practices to create structural engineering outcomes that have a more positive impact on the world around us.And now, net-zero is becoming an electioneering buzz-word with leading opposition political parties declaring an intent to get to net-zero by 2030.
Before we explore the challenges we face in achieving net-zero carbon and the benefits that can be achieved, it is important to clarify what is meant by ‘net-zero’. The definition varies across the industry and there are various forms of emissions that must be considered by those working in the industry: operational carbon and embodied carbon.
The past few decades have focused heavily on operational carbon in construction, which refers to the carbon emissions generated through regulated and unregulated use of lighting, heating, aircon and ICT. We’re seeing buildings becoming more operationally energy efficient over time, and sourcing power from on-site and/or off site-renewable energy sources – with ‘net-zero energy buildings’ becoming increasingly common. My concern, and one that is shared by many others, is that the definition of a net-zero energy building often neglects to consider the other form of carbon emissions – embodied carbon. Embodied carbon refers to carbon dioxide emitted during the manufacture, transport and construction of building materials, together with end of life emissions. In order to deliver net-zero buildings that are truly sustainable, we must always consider the whole life carbon of the building from the outset.