(Bloomberg) —
When calculating our environmental footprint, people usually consider their consumption of things like food, flights, and fuel for heating or run the car. But a major contributor to carbon emissions and creation of waste is often forgotten — the construction of buildings, which is responsible for 11% of energy-related carbon emissions globally.
But by reusing and recycling building materials — things like steel, glass, stone and timber — that total could be cut by almost 60%, according to a report released Thursday. The report, titled Closing the Circle and released by construction firm Mace Group, says London can be a hotbed for “circularity” in buildings given that developers, lessors and planning authorities in the capital all want more sustainability.
The push from authorities to reduce waste has risen since April, when legislation forcing commercial landlords to meet minimum energy efficiency standards to rent out property. In July, the UK government vetoed Marks and Spencer’s plan to demolish and rebuild its flagship store on Oxford Street, London, stating that the carbon impact was a factor in the decision.
London builders are also increasingly interested in greener development, as clients are increasingly look to boost their ESG credentials.
“We have a sustainability pledge,” said Zac Goodman, chief executive of TSP, a property investment company that is a so-called B Corp.
In the decade to 2021, the City of London generated 1.54 million metric tons of construction and demolition waste, Mace estimates, or 2.7 tonnes per worker. Cutting that could keep an additional 900,000 tonnes or almost 60% of materials within the City’s construction supply chain over the next decade. Over London as a whole, this would be 13.8 million tonnes — saving 11.8 million tonnes of carbon dioxide emissions. One tonne of CO2 would fill a sphere about 32 feet in diameter.
The report looked at seven cities in total, including New York, Paris, Madrid, Amsterdam, Berlin and Rome. It concluded some 77 million tonnes of waste could be kept in the supply loop over the next decade if construction firms reused materials, worth £10.6 billion. New York has the greatest potential, with 30.6 million tonnes that could be kept in construction, worth £2.8 billion.
One barrier to re-use is cost. Although reclaimed materials in themselves may be cheaper than new equivalents, recycling has additional costs due to the extra labor needed for reclamation and repair.
Ged Simmonds, Mace’s managing director for commercial offices and residential property in the UK, said the costs are often similar between reclaimed and new materials. But there’s a subtle shift happening to the former, he said: while in the past, people would have chosen new materials over reclaimed ones when they were the same price, that is now reversed. “It’s an interesting flip,” he said.
Some remain slanted against using “second hand” materials in buildings, said David Weatherhead, senior design principal at HOK, an architecture and engineering company. “The societal challenge is the interesting one for me — what are we comfortable with? What’s the status quo?” he said.
Historic cities like London can find that people are already used to the idea of reusing materials, said Goodman.
“Societally and culturally we’re used to living with things that have been reused over a long period of time,” he said. “People enjoy the heritage, charm or sustainability of things that are older than them.”
Examples include the former BT building on Newgate Street, City of London, a Mace project currently under construction and reported to be the new location for HSBC’s headquarters. The project will result in doubling the square-footage of the building, but the central core has been kept. Of the core structure — concrete, steel, aggregates and stone — 76% has been retained, Mace estimates. The Portland stone cladding and granite — 1,500 tonnes of it — is being removed, restored and re-used.
Another example is the reuse of ceiling tiles at another of their developments at 100 New Bridge Street, another commercial address in the City. “There’s nothing wrong with a metal ceiling tile,” said Simmonds. “But historically, four or five years ago, they would have gone in the skip.”
To contact the author of this story:
Helen Chandler-Wilde in London at hchandlerwil@bloomberg.net
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