Authors: Catriona Brady, Director of Strategy and Development & Sara Kawamura, Project Officer, Better Places for People, WorldGBC and Asif Din, Sustainability Director, Perkins&Will and Louise Hamot, Global Lead of Lifecycle Research, Dar & Integral Group.
In WorldGBC’s flagship report ‘Beyond Buildings’, we analysed how three-quarters of the global infrastructure needed to advance development by 2050 is yet to be built. There are simply not enough finite resources to carry on with the current take-make-waste consumption models. A transition to a circular approach is the only solution to balance international development and environmental goals.
The built environment – considering both buildings and infrastructure, in an integrated manner – is a key part of the solution to achieving this. Building materials account for half of the solid waste generated every year worldwide. As much as 32% of landfill waste comes from construction sites, and 13% of materials delivered to a construction site end up being sent directly to landfills without having been used; it is clear that the building and construction sector are responsible for a huge amount of material waste (1).
Reducing waste in the construction process, both by sourcing re-used materials at point of construction, and by returning functional materials to the market at end of life point, offers opportunities for the reduction of excess and surplus building materials seen in many geographies today. Considering that 40-50% of resources extracted for global materials are used for housing, construction and infrastructure, there is clearly a great opportunity for making a positive impact in the built environment sector. The WorldGBC global network is exploring opportunities for resource efficiency and implementing a circular economy at building, infrastructure and supply chain scale – allowing us to facilitate the development of crucial built assets (both buildings and infrastructure).
The Principles of a Circular Economy – for buildings and infrastructure
A circular economy gives us the tools to tackle both climate change and biodiversity loss hand in hand, while addressing important social needs. It gives us the power to grow prosperity, jobs, and resilience while cutting greenhouse gas emissions, waste, and pollution. “We must transform every element of our take-make-waste system: how we manage resources, how we make and use products, and what we do with the materials afterwards.” (2)
The imperative of resource efficiency is its reusability over infinite lifecycles with minimal value degradation. As such, the principle is to use less materials, use recycled materials, create a market for secondary materials and continue to recycle. As a consequence, waste must be eliminated in the model so that all materials are used efficiently and regeneratively, as circularity is also about regenerating the natural environment.
The Need for a Circular Economy – for both buildings and infrastructure
Buildings cannot decarbonise, or fully engage in a circular economy, without infrastructure.
Neither buildings or infrastructure can decarbonise without transforming the supply chain. As both buildings and infrastructure rely on similar supply chain pathways, this can create opportunities for transformation of high resource-intensity sectors that provide long-lived, durable materials for the built environment. Because both sectors rely on similar supply chains, they share synergies and opportunities for material re-use to feed into a circular economy.
The co-benefits of an integrated approach between buildings and infrastructure to achieve a circular economy
Within the building sector, a range of different initiatives exist to show which materials in the urban environment can be dismantled and reused, and are looking to the future to define the inventory of future buildings for reuse rather than looking at existing stock (3). Compiling the raw materials available from both building and infrastructure projects in one collective registry dramatically increases the availability of usable materials.
For example, the majority of concrete used within the construction sector can be reused as aggregate for future developments. The ingredient with the most carbon impact within concrete is the cement component, and although this can be reduced in terms of carbon, it needs the residual product from processes requiring large amounts of fossil fuel. Further opportunities exist in enhancing circularity for both buildings and infrastructure by using, for example:
One methodology to ensure that material flows travel in a closed loop is to make the material manufacturer responsible for its lifespan, and for its handling at the end of service life at a particular location. Certain companies provide environmental services in a similar manner with lighting companies providing guaranteed levels of lighting on surfaces within a building (4). In a solutions based service this makes the specification of equipment the responsibility of the manufacturer.
The consideration of both buildings and infrastructure together in a holistic capacity increases the feasibility of the ‘Products as a Service’ model, by dramatically expanding the market size and providing wider opportunities, e.g. increased longevity of service models for infrastructure projects.
It is important that existing buildings and infrastructure projects are surveyed and disassembled rather than demolished to obtain their maximum material, if not economic value. In the case of future assets, buildings should all be designed with a degree of modularity to reduce waste within construction and allow a standardisation of both building and infrastructure projects to ease future deconstruction. The use of a material passport could be used to make sure all the information on the material can be stored as well as the component be easily identified.
Alignment and consistency between building and infrastructure designers, construction and deconstruction stakeholders will be essential to allow for feasible and effective material reuse. Maintaining a holistic approach and championing a shared narrative is imperative to working towards the goal of circular material utilisation across all built assets.
The growth of cities with new infrastructure and buildings will grow the demand for resources substantially over the coming decades. Circularity within the resource economy of cities will become increasingly important as this growth must be balanced with the embodied impacts of materials and resource scarcity concerns. As the urgency of this situation enhances, we expect the industry to provide better clarity on ambitions and pathways to a more circular built environment to accelerate this process.
We believe that a key part of the theory of change is the integrated approach to buildings and infrastructure on their shared sustainability journey.
Find out more in the full report.