AT chats to Peter Fisher from Bennetts Associates about challenging sloppy claims about building performance and holding journalists to account.

Timber Square by Bennetts Associates, a hybrid timber redevelopment in London’s Southbank, that addresses both embodied and operational carbon emissions.

Bennetts Associates has always been at the forefront of measuring building performance. Is there a risk of becoming so preoccupied with the data that it discourages designers from using intuition and creativity?
Is there a risk? Yes. But it shouldn’t preclude us from just doing our basic homework and measuring what we do. And that in itself can actually throw up stuff that’s counter-intuitive, which makes us look at things differently. So for example, it isn’t as insane to hang concrete cladding off a timber building as it might seem. And at least knowing that is worthwhile and helpful. It’s not necessarily about tell us what we shouldn’t do, or standing in the way of experimentation but is very useful in terms of having data you can point to.

Who takes responsibility for gathering data around embodied carbon?
As a result of BREEAM it has defaulted to service engineers, and I have to say, I don’t think that’s where it naturally sits. Architects should be on top of it, and if it isn’t the architect it should lie with the quantity surveyor. Calculating carbon is effectively about measuring and putting a value on quantities, and quantity surveyors are pretty well placed to do that. Every carbon decision as an impact in financial terms and every value engineering decision has an impact on carbon. It’s about trying to filter through those implications as you go.

Bennetts Associates has published its anti-greenwashing charter in a bid for banish sloppy or downright inaccurate claims about environmental performance. How did that come about?
It genuinely was written as an internal document. It was about challenging ourselves to be more substantive about what we say, and more precise in terms of the language we use. Our next target is journalists. Journalism is increasingly about rehashing press releases, so questionable statements get repeated over and over again. You read claims that a particular project has achieved a 50% reduction in carbon. And you think a 50% reduction from what? What are we taking as the average? It’s infuriating when you see things that you know can’t be right. You look at some of the figures that are thrown around and you think either they’ve hit the magic formula that we’ve never come close to after 30 years of trying, or it simply isn’t true. So it’s about educating journalists as much as practitioners.

How has the preoccupation with embodied carbon impacted on the buildings you design?
One key thing is that it is really affecting the materials we use. The biggest improvements in operational carbon came about from things like LED lights, or heat pumps, which don’t significantly change the way the architecture looks. But the move to more natural materials has a transformative effect. It’s not just about the way it looks. It’s just gentler and nicer and warmer. It even changes the way a building smells.

Peter Fisher is a director at Bennetts Associates