Equals Associate Patrick Carter says choosing lower embodied carbon materials doesn’t mean developers need to increase their spending.

An alarm call for construction

No-one in the built-environment sector can be in any doubt: the climate emergency is real and it is our collective duty to respond.

The stats are alarming. The World Green Building Council – a global climate-action network set up to promote sustainable practices in the construction industry – says that buildings are responsible for 39% of carbon emissions worldwide: 28% from operational carbon (the energy needed to heat, cool and power them), and the remaining 11% from materials and construction.

Bold new vision

In its report ‘Bringing embodied carbon upfront: coordinated action for the building and construction sector to tackle embodied carbon’, the Council outlined a scenario it said must be realised in order to offset the worst impacts of climate change. It wrote:

“By 2030, all new buildings, infrastructure and renovations will have at least 40% less embodied carbon with significant upfront carbon reduction, and all new buildings are net-zero operational carbon. And by 2050, new buildings, infrastructure and renovations will have net-zero embodied carbon, and all buildings, including existing buildings, must be net-zero operational carbon.”

Laudable ambitions certainly, but the problem is that, historically, the industry’s main focus has been on operational carbon (albeit to much success). If we are to treat the climate emergency with the urgency it so obviously requires, we must address the issue of embodied carbon with the same vigour.

What is embodied carbon?

The term is used to describe the carbon-dioxide emissions associated with materials and construction processes throughout the life cycle of a building. It encompasses raw material extraction, manufacturing processes, transportation, assembly, use, deconstruction or demolition, and end-of life-stages.

Ready for the challenge

At Equals, we recognise that as project and cost managers, the onus is on us to steer strategic decision-making for our clients and project team as we work together to reach these targets. This includes finding innovative solutions to embodied carbon – one of the biggest challenges to industry de-carbonisation at this time.

An informed viewpoint is essential if we are to provide our clients with strategic guidance and support. To this aim, we have undertaken an analysis of materials commonly specified in construction projects, comparing their relative costs with those of alternative materials that have a lower embodied carbon footprint.

To do this, we relied on embodied carbon ratings provided by the London Energy Transformation Initiative (LETI), which comprises 800-plus built- environment professionals working to help the capital reach net-zero. The results showed that, in many cases, lower carbon alternatives either cost the same or were more cost-effective than other commonly specified materials.

Comparative cost analysis: the key findings

The graphs below show how commonly used materials compare in terms of relative cost and also their embodied carbon footprint.*

Right time, right place

While our findings are good news for your profit- and-loss sheet and the planet, timing is also a key factor. Making the right choices early in the life of a project will have the biggest impact and help you to procure with confidence later on.

The Product stage (A1-A3) of a project (raw material supply, transport and manufacturing) accounts for the largest proportion (c. 55%) of embodied carbon over the life of a building. Consequently these are the emissions that should be treated as a priority.

In addition, because off-site manufacturing also contributes to a building’s embodied carbon, where you source materials is crucial. Look into a supplier’s carbon credentials before selecting them, and obviously the more local they are, the lower the likely impact of transportation.

Simply by making informed decisions on material selection at the optimum time, it is estimated that embodied carbon can be reduced by up to 20% in the short term, with no additional costs.

5 quick wins for reducing embodied carbon

• Re-use buildings/materials and minimise demolition
• Adopt structurally efficient systems and grids
• Target lean design, and build light
• Avoid over-specification
• Procure local and low-carbon materials

Equals’ key role in decision-making

As construction professionals, Equals can meaningfully inform material choices by establishing project brief targets and ensuring the implementation of an embodied carbon reduction strategy.

This would include costed design studies and market-testing for optioneering and optimising the selection of component materials. We can also advise on the procurement of consultants and contractors who have a proven track record of reducing embodied carbon.

For further information contact Patrick Carter or Neil O’Connell