“This is carbon that goes into the atmosphere now – not spread over the next 25 years,” says architect Peter Fisher, a director at Bennetts Associates and a key driver behind its sustainable projects.
“We need to have a dispassionate analysis of whole-life carbon and, particularly, upfront carbon. Because upfront carbon hugely outstrips ongoing operational carbon. I can state that as a fact. There are people who will say, ‘Ah, but you could knock it down and build a more efficient, modern building’. The arithmetic simply doesn’t work. It’s a disingenuous argument.”
If you take 2050 as the target date for net zero, Fisher explains, the upfront carbon of constructing a new building would probably be five to 10 times what its operational emissions would be between now and then.
Fisher is part of a seismic shift among architects, encapsulated and, to some extent, led by the Architects’ Journal campaign RetroFirst. Given the significant role of the built environment in the climate emergency, Fisher says architects increasingly feel a “genuine sense of purpose” – perhaps in a way they haven’t since the post-Second World War era of reconstruction. “That is definitely coming through in younger architects and students, more so than it has in the rest of my career,” he says.
Early adoption
Bennetts Associates’ first major refurbishment was the transformation of a dilapidated and inefficient 1960s building to provide offices for Hampshire County Council. The remodelling of Elizabeth II Court completed in 2009. “We did look at some very early embodied carbon analysis and it looks very rudimentary from today’s perspective,” Fisher says.
He is project lead for Timber Square in Southwark, SE1, where Landsec is creating 370,000 sq ft in two office buildings with public realm between them.
This is a net-zero carbon scheme, achieved in large part by keeping 85% of one of the existing offices on the former printworks site to create the Print Building with an upfront carbon intensity of 450 kgCO₂e/sq m. Alongside it, the new build Ink Building uses modern methods of construction to help drive its embodied carbon down to 650 CO₂e/sq m. Hybrid steel and cross-laminated timber mean the scheme is around 20-25% lighter than if built using regular materials. The overall development is 550 kgCO₂e/sq m.
Bennetts started work on the project in 2019. “I’m guessing if we had started five years earlier, it would probably have been a case of clear the site and start afresh,” Fisher says. This was the plan for the site’s previous owner, Gaterule.
By this point, Landsec’s agenda was different. In 2016, it became the world’s first commercial property company to have its carbon reduction target approved by the Science Based Targets initiative, linking its targets with the science of climate change. Bennetts Associates had its own science-based targets – covering energy use and travel emissions – approved in 2018, making it the first architectural practice to achieve this globally.
“The brief very clearly said we should prioritise timber construction for new-build and the retention of existing buildings. That retention was for carbon reasons,” Fisher says. The existing structure means Landsec can add several storeys.
Retaining character
Happily, there is another upside to retention over demolition: raw industrial character. Fisher sees the retention of existing buildings as an antidote to the bland steel and glass architecture that has come to dominate commercial office buildings. The language used around repurposing has changed, reflecting an important shift in sentiment, he says. “I think a few years ago, reuse or repurposing would have been called compromise. Now, it is referred to as character,” he says.
He sees corporate occupiers with net zero, science-based targets driving further action – and fast. Often their biggest carbon impact is the building they occupy and their business travel emissions. “People are moving out of buildings into much better ones. For now, many of those are new-build. But then you also get the buildings they have moved out of. What do you do with them? So quite a lot of work we are doing now is looking at those. Even refurbishing buildings we designed ourselves,” Fisher says.
Set a starting point
Fisher isn’t calling for a universal ban on new buildings but when he talks about analysing whether the case for demolition/new-build stacks up, he means environmentally. Where it doesn’t stack up, there may be other justifications. “I think there’s got to be this starting point on embodied carbon,” he says.
“We should have an initial presumption in favour of retaining. That must be a meaningful starting point, not the start of an exercise to justify what you decided you were going to do anyway.”
He believes there will be embodied carbon targets for new buildings. “Most other European countries have got those now. There will probably be some form of taxation placed on carbon,” he says. “And it will probably be quite high: And that changes a lot.” The current value for carbon pollution set in HM Treasury’s Green Book is £252/tCO2 and the UK Green Building Council recommends following this as an internal “shadow price”. “It would add up to big sums of money for the big developments,” Fisher says. “I hope that comes through in some legislative form. I’ve no hope it will under this government, but maybe under a subsequent one.”
Is that what is needed to really make a difference? “Yes. I think once you get a genuine price for carbon that reflects the damage being done and the cost of mitigating it, which is what the Treasury Green Book is intended to do, then that begins to make a big difference.”
He also sees the commercial property sector moving quickly off its own bat.
“Even agents aren’t the enemy anymore,” he jokes. “In fact, they are asking for stuff that’s undeliverable now. There’s no greater zealot than a convert. Agents understand the language and they know what is feasible – and they ask for a bit more than what is feasible.”
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