Building for tomorrow: Implementing circularity and resource efficiency in construction

The construction sector contributes to 25% of total GHG emissions [1] and generates 60% of all waste produced in the UK [2]. To put this into perspective, imagine that 400 million tonnes of materials are used in London each year alone and, on a global scale, only 8.6% of resources are treated circularly [3].

We urgently need a paradigm shift towards more sustainable practices, with circularity and resource efficiency identified as key levers in this transition. Apart from reducing our ecological footprint, this transition promises to usher in a model of sustainable and economically viable production increasing the sector’s resilience using innovative business models.

But what does this mean in practice, and how close are we to achieving a truly circular and resource-efficient built environment?

Understanding the basics: Circularity and Resource Efficiency

Circularity, or a circular economy, embodies a regenerative system where materials are in continuous circulation, mimicking natural processes where nothing is wasted. It represents a profound shift from traditional, linear models of "take, make, dispose" to one where every resource and object is designed from the outset to be recovered, recycled, and reused [4].

In the built environment, circularity means:

Build only what you need: rehabilitating existing buildings when possible.
Build with the right materials: using renewable, bio-based materials.
Build efficiently: every component matters.
Build for long-term value: designing buildings to be maintained, dismantled, and repurposed.

Resource efficiency, on the other hand, refers to the optimal use of resources throughout their life cycle, increasing their lifespan and minimizing waste and environmental impact. In the built environment, we have to select sustainable materials carefully, employ construction techniques that allow for easy disassembly and recycling, and design buildings for adaptability and longevity.

The Butterfly diagram illustrates it [5].

To become more sustainable, the construction industry also needs to incorporate important design changes and unlock collaboration efforts across the entire value chain that will increase circularity and resource efficiency.

Best practices

Now that we understand the concept of circularity, let’s explore some essential principles and best practices in the construction industry.

Cradle-to-Cradle

This design approach reshapes how the industry designs materials and products, considering their end-of-life from the beginning. This contrasts sharply with the traditional cradle-to-grave model, where the disposal of the resource is considered as the final step of the process. This approach, known to be one of the most effective ways to reduce Scope 3 emissions, extends the lifecycle of materials and reduces waste, enabling buildings to be easily repaired, updated, or deconstructed using modularity and standardization.

Materials innovation: number one objective of the OECD RE-CIRCLE project [6]

Steel and concrete are responsible for more than 13.5% of global carbon dioxide emissions [7]. A key strategy to reduce this impact is the use of Supplementary Cementitious Materials (SCMs). SCMs, such as fly ash, slag, and silica fume, can partially replace Portland cement in concrete, reducing the carbon footprint without compromising the structural integrity or performance of the concrete.

For instance, marketplaces like WasteTrade [8] facilitate the trading of recyclable construction waste for better material efficiency. These initiatives reduce waste and encourage a more sustainable approach to material use.

Example of a success story

Arup refurbished old panels to make the new façade of the “1 Triton Square” building in collaboration with the Ellen MacArthur Foundation. It sets a new standard for circular construction that proves to be 30% faster to completion and 48% less carbon intensive [9]. It also represented 66% cost savings compared to a new façade. This achievement stands as a leading example in the industry, but it also brings up further questions about the future of the panels used, pushing us even further to explore how we can achieve true circularity.

Challenges and opportunities

1. Getting involved early

"From the earliest stages of projects, we need to challenge the project brief, our designers and architects to provide more materially efficient buildings. If we are serious about circularity and reuse then early conversations with the supply chain are key to overturn existing standards, specifications and business models." Sam Burdett, Carbon Manager at Skanska

Getting involved as early as possible in the supply chain is essential to ensure sustainable procurement of materials. By finding the right suppliers and manufacturers even before the project starts, construction companies can influence production processes to be more sustainable. This approach enables the integration of circular principles from the outset of a project, ensuring that materials are selected based not only on their performance and cost but also on their environmental impact and potential for reuse or recycling. For instance, the House of Commons report highlights the significant potential of using timber for construction to reduce emissions, also emphasizing the importance of local and sustainable supply chains [1].

Investing in the retraining of industry staff is equally important, as job losses in material-intensive sectors like construction are inevitable. However, these jobs are expected to be replaced by new opportunities in recycling, repair, refurbishment of end-of-life products, and secondary metal production, leading to economic growth. The overall impact on employment is predicted to be slightly positive, with a global increase of approximately 0.03% [6].

2. Using Integrated Systems of circularity

Integrated systems are vital for circularity in construction, enhancing resource use efficiency through smart management. The advent of smart cities, underpinned by Internet of Things (IoT) technology, is a key driver in this transformation. IoT devices allow for real-time monitoring and optimization of resource consumption. The further deployment of Building Information Modelling (BIM) will play a pivotal role by enabling more efficient design and construction processes. BIM, along with digital tagging, ensures that materials can be reclaimed and reused using detailed tracking and management throughout a building's lifecycle. The further use of platforms like Madaster [10] will also enable the registration and tracking of materials, through material passports.

The reluctance of the insurance industry to cover buildings that incorporate reused materials, which may not guarantee the same lifespan as those using new materials, can be an obstacle to the reuse of materials. To address this issue, inter-industrial collaboration is necessary. For example, AXA XL, a global provider of commercial insurance, is a partner in the Ellen MacArthur Foundation's Circular Economy 100 (CE100) network.

3. Going beyond

To transition to a real circular economy in the construction industry, we require more than technological innovation and efficient material use. It demands a fundamental change in mindset across the entire value chain. Collaborative efforts between industry leaders, policymakers, businesses, and consumers are crucial to drive this systemic change.

Moreover, pushing for economic incentives such as taxes, can increase the cost of extracting virgin materials, reducing the impact on the environment while incentivising material recovery and recycling. This could raise funds to be redirected in the form of subsidies to pay for the re-training needed for the construction staff.

Here are some of the existing regulations to look-out for:

Regulation/ Strategy	Date	Description
EU Circular Economy Action Plan [11]	2023 update	Includes the 2023 Circular Economy Monitoring Framework [12].
RICS’s Red Book Supplement [13]	2021, July 2024 Update	Incorporates demolition into its guidelines, marking a significant step towards integrating circularity into regulatory frameworks.
UK’s Circular Economy Package [14]	2020	Outlines a clear directive towards minimizing waste and maximizing resource efficiency. The ambition set forth in the 25-year Environmental Plan [15] is: zero avoidable waste by 2050.
London’s Whole Life Cycle Carbon Assessment [16]	2020	Encourages the consideration of a building's entire lifecycle carbon emissions.
BREEAM UK New Construction [17]	2018	Focus on material efficiency and sets a benchmark for sustainable building practices.

In conclusion, efforts made to reduce the environmental footprint of the construction industry are currently promising but far from sufficient. Steering the construction sector towards a circular economy would alleviate the environmental strain, while also unveiling new economic opportunities and enhancing community well-being.