Designing out waste

The restriction on movement of people and goods caused by the Covid-19 pandemic has exposed the global supply chain to one of the most significant challenges since the birth of globalisation. How could a circular economy help?

WORDS NICOLA CARNIATO, TECHNICAL DIRECTOR AT AKT II

The pandemic is not a short-term crisis; it will have long-lasting implications for how people work and how supply chains function. At a time when the climate emergency is bringing into sharp focus the fact that we cannot continue building as we always have, there is an urgent need for businesses to improve the resilience of their supply chains in preparation for future challenges.

More importantly, the current crises have highlighted the need for a critical reassessment of the present global economic model. The existing, linear economic system offers traditional linear consumption patterns of ‘take make dispose’, which increase the exposure of companies to risks such as higher resource prices and supply disruption, and are causing environmental degradation, climate change, biodiversity loss, and pollution. Design Out Waste

A circular economy will provide a sustainable economic model that is founded on a resilient supply chain and on environmentally focused outcomes. It will also offer opportunities for innovation and creativity to enable this positive, restorative economy. A circular economy replaces the concept of ‘end of life’ with the concept of restoration, and aims to eliminate waste through lasting and nourishing design.

Catalysing opportunities

In the face of supply disruptions and higher resource prices, the call for the adoption of a circular economy is becoming louder. Brexit – and the potential difficulties in transporting materials across borders – could catalyse opportunities for the UK manufacturing industry to secure these material supplies from a stable domestic market, and could stimulate the materials’ circular flow.

Around 400 million tonnes of material are used by the UK construction industry each year, of which approximately onequarter is imported, with some sectors more reliant on imports than others. Almost 70% of timber, for example, is brought in from overseas using carbonintensive sea freight. Yet, with around 100 million tonnes of material wasted each year, the construction industry is

responsible for more than 50% of all of the UK’s waste. These numbers, together with resource scarcity and dramatic rises in the cost of raw material – coupled with the cost of waste disposal – are directing businesses to think of this waste as a valuable resource that can be exploited by adopting more-circular business models: one industry’s waste becomes another’s raw material.

Environmental challenges

Cambridgeshire has experienced a constant growth in population over recent years, with the planning of sustainable expansion across the Oxford-Cambridge Arc set by the Arc Spatial Framework in February. The built-environment industry is under pressure to deliver affordable, high-quality housing, alongside good, suitable working space and other facilities, and to provide clean, green infrastructure without exacerbating climate breakdown or air pollution.

Cambridge sits at the confluence of two important growth corridors – the East-West Arc and the UK Innovation Corridor – but also faces unprecedented environmental challenges, as outlined in the council’s biodiversity emergency declaration almost two years ago. Cambridgeshire and Peterborough combined have one of England’s lowest percentages of land designated as either priority habitat, natural green space or a nature conservation site. Only 6.5% of the land’s surface has statutory or nonstatutory nature-conservation designations, and only around 8.5% is ‘priority habitat’.

Local air pollution is also much higher than the national average, so there is a concern that future development, which comes with growth, will harm the natural environment and the ecosystem services.

Economic recovery

The circular economy offers a solution, decoupling economic growth from resource use and environmental impact, and can shape a pathway towards a more resilient, low-carbon economic recovery.

Alongside material resourcing, circular-design thinking also promotes the benefits of renovating and upgrading existing buildings over demolition, including through a holistic repurposing where appropriate. These renovation projects must increase durability, by selecting long-lasting materials and by considering adaptability and energy efficiency. When all options are exhausted, and once it’s been demonstrated that a building’s retention is not feasible, a pre-demolition audit should be undertaken to identify assets and materials that can be taken out, recovered, and where possible reused.

For new buildings, the designs must be future-proofed to adapt to the needs of future generations, differing uses and climate change. Designs should demonstrate how the buildings will be maintained over the long term, so that any major renewals – such as façade replacements – will not adversely impact the occupants. The designs should also

Recovery of the construction materials

Sainsbury Laboratory: the building was appropriately located within its sensitive landscape. The internal layout allows connectivity among the scientists

Butterfield Innovation Centre: an award-winning business park with sustainability in mind

© Valerie Bennett © Hutton Crow

Allen Pyke Associates

Landscape Architecture & Environmental Planning based in Cambridge

www.allenpyke.co.uk 01223 358 055 v.friedlander@allenpyke.co.uk We are now an Employee Owned Trust

© FCB studios Material Passport

show how the various layers of the development are to be cost-effectively disassembled, to support the recovery and reuse of the building’s systems, components and parts, as and when these need replacing.

The application of circular principles to the design of buildings provides a pathway towards net zero, by specifying materials with low environmental impacts, while also ensuring the optimisation of performance parameters and the consideration of endof-life scenarios.

Design control

Some materials are inherently more carbon efficient than others, but all materials can be specified to deliver better (or worse) carbon impacts. As designers, we must control this. The impact of concrete, for example, can be mitigated with the use of cement replacements such as GGBS (a by-product of the production of steel) and with locally sourced or recycled aggregates. Novel mixes, consisting of alkali-activated materials (AAMs) and geopolymers, can also replace the cement, to provide lower-carbon concretes.

Steel is fully recyclable and can be reprocessed in an electric arc-furnace that is powered by renewable energy. It can also, however, be re-used if not damaged, the obstacles of which are currently within the certification process for reconditioning the steel members. Timber, in many ways, may be considered the ultimate circulareconomy resource, and the ultimate renewable resource – but only if procured

Shrewsbury Flax Mill is a complex restoration of Grade I, II- and II* listed buildings to provide mixed-use facilities

Fourth Age from forests that are sustainably harvested, and if the structural members are designed for reuse and remanufacture.

The circular economy fosters collaboration and innovation towards sustainability goals, thereby increasing productivity and creating new jobs. Collaboration with suppliers and designers can keep used products, components and materials in circulation, while digitalisation can boost this process with solutions such as the ‘material passport’. This gives materials value for recovery and reuse, and can be based on building information modelling (BIM).

This attitude offers the possibility to bounce forwards from this period, by placing the three ‘Ps’ – planet, people and profit – at the centre of growth strategy.