Towards a Circular Economy for Construction in London - Event Summary
As part of the series of events for London Climate Action Week, we hosted an online event to consider how we can accelerate the progress towards a more circular economy for construction in London.
A circular economy in construction means that buildings should be designed to create minimal waste by being long-lasting, allowing them to be easily repaired and refurbished, and to be deconstructed at end of life.
Katherine Adams, co-founder of Reusefully, the research and consultancy organisation dedicated to circularity in the built environment, opened proceedings and described how circularity is about ensuring materials flow in our economy, looking at longevity, productivity and value. It goes beyond reuse and recycling, aiming to maintain the environmental and economic value of products.
There is an intrinsic link to carbon and climate change, with circularity actions addressing upfront and embodied carbon, through to the carbon impact of reuse and recycling.
As well as reducing carbon, there is a need to be much more efficient with the resources we use, due to the impact of global population growth and the loss of biodiversity and water stress. Only 20% of construction materials comes from secondary sources in the UK, and this is often low grade or low value materials such as aggregates. The price of materials and supply shortages are beginning to have an increasing impact.
We remain very wasteful as an industry and have not reduced our overall waste by much. Whilst recovery rates are high (at around 92%), this is often for low value or downcycled applications. 5 million tonnes of construction and demolition waste is still sent to landfill.
The Green Construction Board with the support of Reusefully has produced an interactive “Routemap for Zero Avoidable Waste”, which is a highly useful document she said, helping to understand the actions that are important across different life cycle stages in construction.
Some clients and large developers are also starting to make commitments for reducing carbon and improving sustainability. British Land, for example, are starting to set percentage targets for deconstruction and take-back of materials, together with upcycling and reuse of materials.
Gilli Hobbs, also a co-founder of Reusefully, provided a perspective on circularity in London, highlighting the new London Plan guidance for Circular Economy Statements which gives greater weight to the value retention of existing structures and buildings, shifting the emphasis to using and reusing what we have got. The guidance now requires ‘pre-redevelopment audits’ to set out the justification for demolition or otherwise, encouraging the reuse or retention of whole building assets in part or whole where possible. If demolition is required, pre-demolition audits are then undertaken, with a much tougher set of requirements in the recent guidance, which is a very welcome development.
Gilli provided examples of how this value hierarchy is starting to work, aiming to get to the highest value of reuse or recycling where buildings are no longer required. This includes
Meridian Water, a project in Enfield which is a 30 year regeneration programme which Gilli is working on. The project is taking a life cycle approach to circular economy, even going so far as linking existing buildings ‘donors’, with new construction projects elsewhere. Meridian Water is also looking at future design issues, with a focus on greater adaptability and reuse.
Christian van Maaren of the Excess Materials Exchange, based in Amsterdam, said that in many ways the circular economy is ‘stuck in the future, whereby everybody wants to see it happen, but the practicality of matching supply and demand of secondary materials is difficult’. He says that London has now moved ahead of the rest of Europe in circularity.
Christian described how material or resources passports could work in future, and the need for standards in this area. He highlighted the work the Excess Materials Exchange is doing in ‘collective intelligence’ to enhance data on reusable building materials, using the knowledge and experience of experts in the field. Christian is also involved in the Enfield project, and on other projects such as Schiphol Airport looking at how tools such as RFID tags or OR-codes for reusable materials can help enhance value. The information in passports also makes it much easier to understand life cycle impact of products.
Nitesh Magdani, founder of Net Positive Solutions outlined his role advising on design solutions at Meridian Water, through wide stakeholder engagement to promote circularity and the reduction of whole life carbon. This involves the creation of a route map for stakeholders (clients, designers, contractors and others) and the generation of circular business models. He also shared case studies from his experience of circular design and construction in practice’, highlighting examples including ‘Circl’, the ABN AMRO Circular Pavilion in Amsterdam which is designed to help them as a client understand circular economy themselves and showcase this as a concept to their banking customers. Lendager Group in Denmark have an example taking repurposed bricks to make construction panels, designing in reuse as architects and developers in a project called Resource Rows.
Examples in London, include the Circular Building created for the London Design Festival a couple of years ago, which explored how you can design for the next life and reassembly, maintaining residual value after first use. Nitesh, Katherine and Gilli are also working with the whole life carbon community to quantify the carbon saving value of reuse and other circularity approaches, which is not currently understood or recognised within the current whole life carbon debate.
A lively discussion followed the presentations, highlighting topics such as the metrics that are used for measuring carbon impact and their relationship to circular economy thinking, the materials value retention hierarchy, the need to change culture and ways of working in the construction industry. Both speakers and attendees agreed that creating triple bottom line analysis together can be very impactful in winning hearts and minds in favour of circularity. Highlighting the quick wins, the (financial and carbon) impact of high value materials also helps, together with linking demolition and redevelopment with reuse. All agreed we have made a start, evidenced by some of the research and case studies highlighted, but only a start and we need to accelerate our efforts to bring all stakeholders on board.
