Increasingly important weapons in the architect’s armoury

Recently, a report from the Global Alliance for Buildings and Construction (GlobalABC) found that the climate performance of the sector and the 2050 decarbonisation pathway is widening. Among a slew of predictably dreary statistics was that the building and construction sector’s energy consumption and CO2 emissions have rebounded from the pandemic in 2020 to an all-time high.

At every summit, the construction industry promises meaningful action. Yet each year, we are presented with statistics that suggest we’re making little genuine progress.

At last year’s COP26 summit in Glasgow, Enlai Hooi, the Copenhagen-based head of innovation at Schmidt Hammer Lassen Architects, contended that an architect who creates just three typical buildings over their career will be responsible for carbon emissions equivalent to the lifetime emissions of 162 typical Americans. And with the built environment generating 39% of annual global CO2 emissions, it is widely acknowledged that those designing the buildings have a vital role to play.

Increasingly, in the earliest phases of the building’s design, architects are having to consider the whole-life carbon impacts of their projects, which includes the estimated quantity of operational and embodied carbon.

Operational carbon – the energy needed to heat, cool and power our buildings – currently accounts for 28% of the estimated 40% of CO2 emissions emitted by the industry. While embodied carbon - emitted whilst producing a building’s materials, their transport and installation on site, as well as their disposal at end of life - contributes 11%.

This disparity perhaps explains why the construction industry has expended more time and effort in reducing operational carbon. However, a shift in mindset, particularly for architects, represents a clear opportunity.

At every summit, the construction industry promises meaningful action. Yet each year, we are presented with statistics that suggest we’re making little genuine progress.

For architects, embodied carbon is crucial to consider from the earliest planning phase. Unlike operational carbon, which can be reduced during a building’s lifetime, embodied carbon can never be recaptured.

An increasingly popular method of measuring the environmental impact of a building’s design is Life Cycle Assessments (LCAs).

Described by the American Institute of Architects as one of the best mechanisms for allowing architects to understand the energy use and other environmental impacts associated with all the phases of a building’s life cycle, LCAs serve as an accurate environmental footprint calculator.

LCAs bring a host of benefits, not least, arming architects with the data to determine which part of their project is the most resource and energy intensive. By knowing the effect on the planet, across 15 different impact categories including climate change, ozone depletion, eutrophication, human toxicity and water and land use, it can help architects to evaluate which products and sections of the building have the highest potential to make a positive impact.

More recently, the industry has experienced growing demand for another document that quantifiably demonstrates the environmental impacts of construction products: Environmental Protection Documents (EPDs). While LCAs are the foundations of an EPD, the latter is the third-party accredited document that demonstrates the environmental credentials of a product in a standardised way.

EPDs are increasingly sought after by clients but are equally useful to architects and specifiers who can be sure of meeting the growing sustainability requirements of their construction projects.

Unlike operational carbon, which can be reduced during a building’s lifetime, embodied carbon can never be recaptured.

These documents also deliver important benefits on a more macro level, such as increasing transparency. Greenwashing continues to be the scourge of the construction industry, so anything that can help to combat this can only be a good thing.

LCAs do this by helping major stakeholders substantiate their environmental claims using credible data, while EPDs are the internationally recognised seal of approval, detailing this information in a standardised way.

There are those who argue that LCAs and EPDs can lead to scepticism, by largely relying on a simplified model and assumptions. While this may be true in some cases, the thorough insights and transparency it offers far outweigh this. Furthermore, the levels of accuracy and sophistication are only going to grow as technology becomes more advanced.

One thing that LCAs and EPDs don’t account for, however, is those sustainable products and solutions that have been created out of waste products, and thus diverted waste away from landfill. You cannot apportion a reduction in environmental impact directly to your project but by choosing products with a high recycled content you are removing considerable risk from elsewhere.

Additionally, greater consideration has to be taken when calculating the end-of-life potential of products. Both of these represent the next step in the industry’s quest for complete environmental transparency in the planning phase.

That said, LCAs and EPDs have become indispensable weapons in the architects’ armoury.