Landscape Architecture in a Circular Economy

2nd February 2022

Achieving circularity in the built environment requires a paradigm shift away from the status quo. This article talks through why we need the circular economy, what the circular design principles are and the pathway to circularity.

We’re living in an age of waste. Currently society takes, makes and wastes materials, which is great for growing GDP but disastrous for the planet. Simply put, limitless economic growth on an ecologically finite planet is unsustainable. Currently:
• A typical housing development wastes 1 house worth of materials for every 5 houses built;
• The built environment sector alone is responsible for 54% of waste generated in London;
400m tonnes of materials are consumed by the built environment sector in the UK annually;
• Just 5% of land mass is left untouched by human activity.

Image adapted from the Mayor of London Design for a Circular Economy Primer

“We have an economy that tells us it is cheaper to destroy earth in real time, rather than renew restore and sustain it”
Paul Hawken, Environmentalist

A circular economy built on the principles of reuse, refit, repair, refurbish, reclaim, and retain, keeps materials at their highest value for as long as possible and decouples growth from resource use. Circularity shifts reliance away from virgin material extraction which can consequently avoid unethical mining practices, reduce embodied carbon emissions, limit waste management costs, save on material purchases and ultimately protect the natural world.

Image taken from The London Plan

Positively The London Plan 2021 has adopted circular economy into policy – SI 7. Now, all referable schemes, must submit a Circular Economy Statement which promotes circular design principles and aims to be net zero-waste, however could this policy go further? Should it not be applied to all developments?

There’s a strong argument that the built environment sector industry, which has such a profound impact on the environment, should take the lead in promoting a circular approach and not wait for policy to force our hand. Although stringent policy will be crucial to the circular transition, it takes years to work through bureaucratic systems. Is it not up to us, as designers, to act now and address the climate and biodiversity emergency?

“Instead of looking for hope – start creating it” Greta Thunberg

The Circular Design Principles

Minimise resource use and avoid waste
The less you need to change in the landscape the higher the savings on energy, water and labour. Easy wins include preserving what’s already in place. For instance, often paving just needs a jetwash and weeding between the cracks to give it a new lease of life. Outerspace took this approach for our recent office courtyard enhancement project, Arlington square. By avoiding the need for new paving we saved the client money and reduced the impact on the planet. Other materials to retain could include existing trees, furniture and planting.

Before and after images of Arlington Square, an office courtyard enhancement project

Design for longevity
Closing and slowing material lifecycles is a core principle of the circular economy. Avoiding practices like changing a materials state or composition keeps it in the loop for as long as possible. For example, instead of mulching a timber beam for planting, keep it whole to use as a seating or play element instead. It could be that in 20 or 30 years time the wood weathers or decays and at that point shredding it to mulch may be appropriate. In the time saved from lengthening the material lifecycle another tree could reach maturity and provide for a new furniture piece.

Design for adaptability and flexibility
We must design and construct in a way that allows for easy maintenance later in its life. Before the mid-20th century western society lived in a circular manner, we built robustly and fixed things when they needed fixing. It is only in the last 70 years or so which the take, make, waste culture has proliferated. The monumental impact of human activity on nature was clearly articulated in David Attenborough’s recent book and TV series A Life on Our Plant; which highlighted that total area of remaining wilderness dropped by 30% just in Sir Attenborough’s lifetime.

We’re now in an age where almost all the materials we need are above ground, Duncan Baker Brown in his book, The Re-use Atlas, uses the phrase ‘Mine the Anthropocene’. We must start looking inward to our urban environment for our raw material stock and stop overturning what’s left of our natural environment. There are some fantastic suppliers out there now whose core ethos is repurposing/ reusing materials. Ashwells Reclaimed Timber recently delivered a CPD to the Outerspace team on reclaiming and repurposing tropical hardwood and we’ve since seen great enthusiasm from clients to specify their products. Furthermore we’ve seen the emergence of Globechain, which although is in its infancy in terms of what it can provide architectural projects, are certainly an exciting prospect to supply reuse materials for the future.

“You’ll now find more gold in a tonne of iphones, than you would in a tonne of the best gold ore in the world”
Duncan Baker Brown, Architect & Author of The Re-use Atlas

Design for disassembly
When approaching a project, always design with disassembly in mind. Our urban fabric is ephemeral. Therefore, we must design with the knowledge that most materials will outlast a development’s lifetime and be repurposed for another project in the future.
A key principle when designing for disassembly is to avoid the use of toxic chemical products since they compromise a material’s composition and adaptability. For instance, can nuts and bolts be used instead of adhesives? Or a natural aesthetic specified instead of painting/ staining?
Other ways to design for disassembly include building with standardised units instead of bespoke products.

Pathway to Circularity
Forecasting the pathway to a circular economy was discussed at length during the recent ACAN (Architects Climate Action Network) Circular Series. A key discussion point was introducing a RIBA stage 8 into project programs for deconstruction and reuse. Perhaps the industry is not too far off but it will need top-down steer. Watch this space.
Another helpful tool could be Material Passports, a data set to help source re-use materials. Material passports would truly allow us to mine the Anthropocene by mapping materials throughout the city. When a development is up for demolition, this would be flagged and a new development at concept stage could reserve the stock for their project. As more practices get up to speed with BIM softwares making use of this technology will become far easier.
Other barriers in practice include upskilling staff to be comfortable with technically delivering ‘reuse’ designs, sourcing local materials reliably, value engineering and, perhaps the trickiest, convincing clients to adopt a less polished aesthetic. Ultimately, we are consultants and it’s our clients who make the final call but that shouldn’t stop designers putting forward the strongest possible argument for circularity.

“In 2050, we live well, within the planet’s ecological limits. Our prosperity and healthy environment stem from an innovative, circular economy where nothing is wasted and where natural resources are managed sustainably, and biodiversity is protected, valued and restored in ways that enhance our society’s resilience. Our low-carbon growth has long been decoupled from resource use, setting the pace for a safe and sustainable global society.”
Environment Action Programme to 2020

Landscape architects are well placed to spearhead the circular movement due to our wholistic understanding of the physical and biological processes. Designing out waste is another crucial string to our bow in tackling the climate and biodiversity emergencies this urban century.

Outerspace pledge to push for circular design practices on all of our projects.

Soon we will have a ‘Climate’ tab on our website to transparently share how we are becoming more eco with our projects, practice and profession. Keep an eye out on our socials.

The 7th Environment Action Programme (EAP)
ACAN circular economy series

Written by Alex Lowenhoff, Landscape Architect