Why circularity is the key to reducing the carbon footprint of civil engineering


Almost half of the materials extracted from our planet each year in the world are destined for the built environment. This is a difficult read, especially when, compared to other sectors, the construction industry has made little progress in becoming resource efficient and the traditional ‘take, make, throw’ approach remains. much easier option.

Philippa Spence is Managing Director UK at Ramboll

We have not seen enough initiative or dynamism within the sector, at COP26 or elsewhere, to develop effective circular practices that could remedy this imbalance, despite the fact that the scale of our sector presents huge opportunities. So how do we make this change?

As we expect the world’s population to approach 10 billion by 2050, the global housing stock is expected to double in size, with a city the size of Paris being built every week. It is clear that drastic action on the functioning of our sector is urgently needed to limit the associated emissions and the resulting climate impact.

Two key things must happen to effect this change, the first coming from government. Resource efficiency in the built environment must be enabled, encouraged and enforced through policies. Market forces will not be able to counteract the short-termism of profit margins generally required by the private sector, which discourages investment, change and R&D. With insufficient motors for reuse and recyclability, we won’t get the traction we need.

Second, the industry itself has the power to have an immediate and positive impact, and we need to generate internal pressure for change. Ramboll co-wrote a report on Bring in the incorporated carbon from the start with the World Green Building Council, which sets out the following four key principles for tackling embedded carbon: Build nothing – explore alternatives; Build less – maximize the use of existing assets; Build smart – optimize design and material use, design with low carbon, recycled or salvaged materials, for disassembly and for flexibility and adaptability; and Build Efficiently – use low carbon construction technologies and eliminate waste, build for resilience, durability, serviceability and repairability.

The answers to the challenge of circularity lie in these four principles, but this presents a challenge in a fragmented industry with large and complex supply chains characterized at times by competing interests.

We cannot hope to make a difference through single solutions, but rather must prioritize the system as a whole using established industry tools such as full life cycle carbon assessments and cycle cost. life to measure and record the benefits of circular solutions. Being loyal to carbon throughout the life cycle, we also need to ensure that we consider the climate impact on our built environment, which can mean in some circumstances that we need more material to ensure longevity and to resist. to anticipated changes in our climate.

The business case for the circular economy is increasingly quantified. In a report recently launched by the World Business Council for Sustainable Development, written by Ramboll and Lendager, it highlights the economic value of avoided costs, increased asset value, rental price advantage, the market differential and rapid sales. Reports like this and growing evidence are essential as circularity is not detailed in the valuation of assets and is seen to have no measurable economic return on investment, which this latest report also helps to achieve. solve by guiding companies on how to develop the business case.

Despite the growing evidence and opportunities, we still have a bitter struggle to develop a resource-efficient industry on time, not least because:

  • The cost of virgin materials is lower than that of recycled materials
  • The costs associated with increasing the skills and logistics required for circular practices are substantial
  • Landfill costs remain low
  • We have a lack of experience in our complex value chains, which leads to higher perceived risks and reluctance to provide financial support
  • Lack of market volume or economies of scale for new and innovative circular products
  • Lack of customer demand in many market segments and geographies
  • We need circular design principles incorporated into all engineering, architecture and design courses and industry training guidance.

This balance must change if the business case is to be more competitive in terms of competition. As an industry, we can make some contribution to this change, but we need government intervention.

First, we need a stronger government intention to instill the confidence that will allow the supply chain, logistics and storage capacity to respond and serve, anticipate demand and deliver the goods. quality products where they are geographically needed.

Improved subsidies and market incentives to increase the use of secondary materials and products are also needed, as well as an update of building codes to include embodied carbon and material specifications / certifications for material reuse. that can be applied consistently. Waste legislation and standards also need to evolve to enforce more stringent landfill regulations and facilitate the reuse of secondary materials.

Finally, the reform of the tax system could also help to promote the reuse and reallocation of existing buildings over new construction (UK VAT is charged at 20% on repair, maintenance and adaptation of buildings while that new buildings are not subject to VAT).

Those of us who operate in the built environment can and are already making changes wherever possible to be more efficient in the use of resources, but we cannot do it alone and we need the acceleration of the process. support and government policies to enable widespread change.

  • Philippa Spence is UK Managing Director of Ramboll

Do you like what you read? To receive New Civil Engineer daily and weekly newsletters, click here.