Peter Swallow, Sustainability Lead at Grimshaw shares his viewpoint on designing a circular built environment from our latest 'Circular London: Building a renewable city' report.

Embracing circular design principles is key to transitioning the built environment towards a regenerative future, one that balances human needs without transgressing our planet’s environmental boundaries. There are broadly three circular design principles; firstly, extending building lifecycles through transformation and refurbishment; secondly, reuse and recycling of material; and thirdly, flexible disassembly and adaptable construction.

Since Grimshaw’s inception, the practice has been at the forefront of implementing these principles as part of its philosophy that buildings should be flexible and adaptable for the long term. The following case studies demonstrate the successful application of these principles across three of our recent projects.

Finding opportunities for the creative adaptation of existing buildings is key to avoiding emissions associated with demolition and rebuilding. One notable example is the adaptive reuse of the Herman Miller Factory in Bath. Originally designed with loose-fit principles in 1976, the building was transformed to accommodate the Schools of Art and Design for Bath Spa University in 2019. The project focused on adaptability and disassembly. By reusing 90 per cent of the original facade and improving its thermal performance, emissions associated with demolition and rebuilding were avoided. The reuse of the existing building had a positive economic and environmental impact when compared to a new build equivalent.

As part of the EU grant-funded Circular Construction in Regenerative Cities (CIRCuIT) project, Grimshaw collaborated with Simple Works and Buckland Timber to run a demonstrator project focused on evidencing the viability of reclaiming timber from demolition sites for reuse in the fabrication of glue laminated timber. The timber was collected from a demolition site in South London, assessed for damage, removal of fixings and testing. The useable timber was fabricated into six glue laminated beams and mechanically tested at Napier University to confirm that their strength was equivalent to that of beams made from virgin timber.

Building on the lessons learnt from the practices experience delivering flexible and adaptable building, the Civil Engineering Building for the University of Cambridge, completed in 2019, incorporates a flexible spatial framework to maximise internal layout flexibility. Employing a regular planning module, zoning of heavy and light engineering activities to avoid operational disruption. The primary structure and facade systems were designed for deconstruction and reuse in mind to allow for future expansion and adaptation of the building as the masterplan for the wider engineering campus developed, with an estimated 80 per cent of the structural steel and façade components are recoverable. 

Despite the existence of technologies, materials and strategies that support a circular built environment, there are still perceived barriers related to cost and programme holding back their wider adoption. Early consideration at project inception is key to their successful adoption as part of an integrated design solution that many cases can improve construction costs and delivery timelines.

In conclusion, the case studies highlighted exemplify the successful implementation of circular design principles. By extending building lifecycles, reusing materials, and embracing flexibility, we can create a sustainable and adaptable built environment. Overcoming barriers and promoting early adoption are essential steps in accelerating the transition to a circular built environment.