Construction never stops. With the pandemic more or less under control, buildings continue to be erected around the world at a speed few can fathom. And what impact do all those constructions have on the environment? According to the World Economic Forum (WEF), accurate carbon emissions data is available for less than 1% of new buildings worldwide. It is known that the global built environment is one of the biggest culprits driving global climate change, responsible for more than a third of the greenhouse gas emissions that are destabilizing the climate system and threatening our way of life.
To make the construction of net zero buildings a standard practice, the volume of emissions generated by a building across its full lifespan. Real numbers to be assigned to how much carbon is generated by building materials, construction practices, and the ways buildings are used. If it were possible to ‘see’ the carbon in buildings, from design and construction to habitation, humans could find ways to remove it. But more data is needed.
1. Energy efficient buildings
The global property sector is wisely refocusing on energy efficiency. Energy used to power, heat and cool buildings is precious. Cutting buildings’ day-to-day energy use through measures like insulation, passive design, lower carbon heating and cooling systems, and behavioral change by occupants is essential.
A building’s carbon emissions, however, are not all generated through its operation. Research from the WEF with the World Business Council for Sustainable Development shows that as much as 50% of typical buildings’ emissions come from embodied carbon: the emissions that enter the atmosphere during the production and transport of building materials and as part of the construction process.
It is important to understand the details of buildings’ embodied carbon emissions if we are to measure their “whole life carbon” impacts: the total amount of carbon that buildings emit over their lifespan. Whole life carbon data is the tool that will allow us to be precise about designing and constructing buildings with the lowest possible total emissions.
Structural engineers need to know how much embodied carbon comes with the concrete or steel supplied by different producers. Mechanical engineers need to know how decisions about a particular building façade will impact on the capacity of a cooling system.
Electrical engineers need whole life carbon data to understand the scale of embodied carbon attached to a cable tray or conduit. Until comprehensive data on buildings’ whole life carbon emissions are built, it won’t be possible to know when the best choices to achieve the deepest carbon cuts are being made.
2. Building carbon assessments
Arup is committed to carrying out whole life carbon assessments for all its building projects work. The WEF has collected and analyzed data for almost 1,000 building design projects across 30 nations on five continents. New, industry-relevant insights have emerged about the scale of embodied carbon across different building sub-systems as part of this work, and this information is being used to drive fact-based decision making. It is now known that carbon intensity increases during the later stages of most design projects and we’re homing in on which decisions drive this escalation.
The United Nations’ High Level Climate Champions have set a daunting goal for the built environment industry: to ensure all new and refurbished buildings are net zero in operation and reduce their embodied carbon by at least 40%. Carbon reduction at this scale and pace is essential to prevent catastrophic climate change.
Scaling and accelerating net zero buildings will only be achieved if the built environment industry collaborates to build comparable and open whole life carbon data. Delivering complex buildings that meet the needs of the modern world is something the sector does well. Carbon emissions produced by buildings need to be halved in less than a decade, and whole life carbon data is a powerful tool to achieve that.