When Will Arnold called for the introduction of a Grade III listing to make the reuse of existing buildings the default, his main intention was to provoke.
But the head of climate action at the Institution of Structural Engineers, who set out the idea first in The Architects’ Journal and then in The Times last year, remains serious about curbing the UK’s enthusiasm for demolition and new build.
As buildings become more energy efficient and electricity generation is decarbonised, embodied carbon is becoming a more significant part of the whole-life carbon of a new building and must be reduced if we are to achieve a net-zero economy.
EG caught up with Arnold to find out more about his drive to put real estate at the forefront of the battle.
Why focus on embodied carbon?
Embodied carbon in the UK is in total about 50m tonnes a year – more than aviation and shipping – and we don’t have a plan to reduce it. But we know how to; it is very much a problem we can tackle.
Some 50,000 buildings are demolished each year to be replaced by new ones, despite the existing buildings being structurally sound. People are demolishing things like 1990s offices.
We realised that the biggest way to save embodied carbon is to use the buildings we’ve got.
As the grid decarbonises, more of the carbon footprint comes from embodied carbon and two thirds of the embodied carbon is the structure. I do believe we need a solution to stop so many buildings being demolished.
We think single use plastic is a bad idea. But for some reason, single use buildings are normal.
What are you doing now to change the UK’s approach?
We are campaigning for the regulation of embodied carbon in the UK. A group of authors, including myself, put together the Part Z proposal for amendments to the Building Regulations that could be used to mandate the reporting and limiting of carbon emissions [made public in April 2022].
Two hundred companies gave their support. They are trying to do this anyway, and they feel hampered by a lack of regulation.
They have to respond to what the client wants each time. If it was regulated, they could take a consistent approach. There would be a level playing field – not just those companies that care about the future of the planet acting.
We really firmly believe we need this as a country. Other countries in Europe are already doing this. Regulation of embodied carbon would lead to a lot less demolition.
How would Part Z work?
What we advocate is a “measure first, limit later” approach, mirroring the Netherlands. It started requiring reporting of embodied carbon in 2013, then started limiting it in 2014. You need data.
We are [pushing for] reporting from 2025 and then limits to be set from 2027.
Does the property sector support Part Z?
Loads of developers are supporting this – including Grosvenor, Stanhope, Landsec and Lendlease. For the most part, the property industry has been very, very supportive.
There will always be parts of the industry which don’t agree but generally the property industry has been very much behind the Part Z campaign. It has galvanised the industry to push for something.
How important is it for engineers to influence developers?
It’s our job to show the art of the possible. The best buildings come out of a strong and honest relationship between the development side and the design side.
If a client already knows what they want and asks you to deliver it then it’s not design, it’s shopping.
Name a reused building you admire?
The Hylo office building in the City [103-105 Bunhill Row, EC1] is amazing.
It has shown how it is possible to stack an extra 13 storeys on top of the existing structure. More than 2,500 tonnes of CO2 were saved by designing it around the original structure.
When would demolition be OK?
We need to retrofit more. It’s not always the right answer, but it would be good if we always had to consider reuse first.
If it was for the greater public good or social benefit, there could be a case for demolition.
To send feedback, e-mail julia.cahill@eg.co.uk or tweet @EGJuliaC or @EGPropertyNews
