Figure 1. A circular economy for the built environment
These four fundamentals of design offer practical applications of circular economy Principles 2 and 3, as defined by the Ellen McArthur Foundation (2015).
Design for longevity: the use of durable components in the building fabric (e.g. roof, walls and floors) and applying a ‘systems thinking’ design approach to deliver optimal day-to-day building performance and to provide for long term resilience to climate change.
Design for service: enhancing the experience of the occupant by building for quality, using materials that require low maintenance, are non-toxic and allergen free. The building’s design, layout and furnishings should promote occupant wellbeing and facilitate high productivity.
Design for reuse and refurbishment (at multiple scales): It should be possible to upgrade or repair fixtures and refurbish furnishings in order to minimise consumption of natural resources. The building’s layout should provide adaptable spaces; enabling occupants to change how areas are used (e.g. loft to bedroom). At the macro-scale buildings should be designed with changes of use in mind (e.g. commercial to residential).
Design for material recovery: BIM will enable asset managers to schedule maintenance programmes for fixtures (such as boilers and solar panels), and the ability to identify original manufacturers of components will facilitate repairs and upgrades instead of direct replacement. BIM also provides demolition contractors with an accurate bill of materials so that, if a building must be deconstructed, valuable components can be targeted for recovery and reuse whilst other materials can be marked for recycling. This final design fundamental aims to maximise resource utility if a building must be deconstructed.
This vision of a circular economy establishes the building (domestic, residential or commercial) as the final product and the individual construction materials (i.e. bricks, blocks and roof tiles) as components. This distinction is essential for the realisation of a circular economy, as a holistic approach invites all stakeholders to consider the impact of their role in maximising and sustaining the value of the components (i.e. natural resources) within the building.
Critically, the model also acknowledges that human decision-making has an influence on the circular economy, which many early interpretations have failed to address. If occupants are dissatisfied with their environment they are more likely to make changes to the fixtures and fittings before these components reach the end of their stated service life. Therefore constructing a quality building that promotes occupant wellbeing will be a critical success factor in achieving a circular economy.
We believe that BIM will play a pivotal role in developing a circular economy for the built environment. Not only does it facilitate better design through a digital platform for ‘systems thinking’ (the collaboration of multiple stakeholders); it will lead to more effective long-term asset management and will ultimately decrease the consumption of natural resources in the built environment.
 Principle 1: Preserve and enhance natural capital by controlling finite stocks and balancing renewable resource flows is not addressed in detail since this principle can be pioneered by component manufacturers via the component design and manufacturing process. It is anticipated that this is addressed before components become part of the final product: the building.