Circular construction model: entire supply chain involved
In order to change course, begin reducing construction waste and increase the circularity rate, not only contractors but the whole construction value chain must be involved. For circular construction to be as high-grade as possible, the business model of all supply chain partners has to change. Architects and owners have to decide whether old buildings will be reused or demolished, as well as how buildings can be easily converted for new owners.
For instance, they may opt for more sustainable construction methods such as timber construction. Suppliers can offer bio-based materials (e.g. wood, straw, flax and hemp), and demolishers can ensure that building materials are reused at the highest possible grade. All supply chain partners – from owner and architect to demolisher – need to embrace circular principles to make the process a success.
For demolishers, opportunities exist in circular construction through smart demolition. They can extract whole building parts from a demolition site by dismantling the building in a way that specifically allows these parts to be reused.
Distribution of such materials provides new opportunities for wholesalers, who have networks of contractors and can therefore buy used building materials to sell again. If the trend of circular construction continues, this will result in fewer sales of new building materials for suppliers, as "old" building materials are reused more frequently.
The chart below summarises the most important changes to be made for the circular construction process to be able to take place. See further our circular construction report which answers the following questions:
Who does what?
An increasing number of construction companies have ambitions in circular construction. Several large European construction companies are trying to promote circular construction, decreasing the amount of waste and improving the circularity rate. Here are some examples:
Bouygues Construction is transforming its building processes in the supply chain to implement circular economy strategies. To do so, they've outlined four priorities: selecting sustainable and recyclable materials in the design phase, reducing the amount of resources used during construction, recovering and re-using materials on-site and recycling materials. At Hôtel des Postes, Bouygues re-used structural components, doors and external joinery along with various other building parts. For instance, they repurposed the old carpet for new insulation.
Skanska focuses on resource efficiency by reusing and recycling materials and products where possible. Concrete, demolition waste, mixed construction waste and wood are the four largest waste types for the company. They reduce waste with smarter design, planning, procurement and logistics.
In 2022, 72% of total waste was recycled, 8% was set for reuse and 13% received another waste treatment. 6.8% of generated waste went to landfill, which does not yet meet the company's target of less than 5%. Skanska applied circular solutions during the construction of the office building Epic in Malmö, using concrete from the Copenhagen metro, excess bricks from the Epic façade, window frames and beams from other demolition projects, and recycled PET bottles for sound-absorbing canvas in the façade.
Hochtief has a sustainability plan, with goals for 2025 outlining various targets. Circularity is just one of the dimensions, with targets including an 80% recycling rate of waste in 2025 and a consecutive increase thereafter. In 2022, the recycling rate hit 88.7% – already exceeding the original target.
Promoting life-cycle analyses by actively engaging clients in at least 200 building projects in 2025 is yet another target. Hochtief also intends to increase the proportion of projects in which the used materials are digitally logged by at least 10% per year, which should make the reuse and dismantling of used building materials simpler.
Circularity is one of the six key themes for BAM’s sustainability strategy. In the short term, it aims to enhance the transparency of material usage and offer circular construction methods. The company's circular construction initiatives include the "Madaster Platform", a digital tool that documents the materials used in construction projects and promotes their reuse.
By 2030, BAM plans to reduce non-biobased materials by 50% compared to 2019 levels. Additionally, the company strive to reduce its production construction process and office waste by 75% by 2030 compared to 2015 levels.
It's now become critical for a real shift to take place in the construction sector if rising waste levels are to have any chance of falling. Stronger regulation could solve one part of the puzzle, but the transition needs to be covered every step of the way – from clients and contractors to demolishers and the building material industry.
Larger construction companies are already adopting circular policies to help turn the tide, but smaller companies must also step up efforts for any real change to occur. The construction sector is very fragmented, with a high number of these smaller firms playing a key role – and it's crucial that action comes from all sides moving forward.
