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Cat A fit-outs: the real carbon gap

Ella Smith & Craig Robertson

Ella Smith and Craig Robertson explain why AHMM investigated the fit-out/rip out cost relationship, and reveal some surprising statistics

AHMM’s new report, Fit Out//Rip Out was prompted when a member of our design team asked if we had data on the carbon impact of a Cat A fit-out. We realised there wasn’t any on which you could base informed decisions. Our research is usually based on real-world problems, so we’ve looked at four of our projects and expanded that into a piece of work that is relevant to the wider industry.

At present, if fit-out is factored into carbon calculations it is done so naively; RICS’ methodology assumes everything will stay in place until the end of each component’s service life. It’s difficult to say how often rip-outs happen but we’ve compared the RICS assumption with the worst-case scenario, and the carbon cost is about two and a half times greater, so around 40% of the life-cycle carbon in a building is currently unaccounted for. Reducing that would be a massive win.

Craig Robertson. Credit: AHMM
Ella Smith. Credit: AHMM

The four fit-out types we examine range from ‘substantial’, with air-supply ductwork and suspended ceilings, to ‘subtle’, with mixed-mode ventilation and exposed concrete soffits, and we distinguish between elements that can be ‘baked in’ and those ‘at risk’ of being ripped out. There is no single right approach. Some agents we spoke to believe ‘subtle’ is a hard sell, but we could develop a more circular economy around component-based elements that often get chucked in a skip – as we’ve seen recently with raised access floors.

We also look at the drivers for repeated rip-outs, such as leasing patterns and the marketing of space. Solving the problem will involve everyone in the industry, including landlords, agents and tenant groups. Architects can contribute in various ways, from design for adaptability and better communication of the comparative carbon cost of design choices, to developing more convincing ways of marketing through technology like Virtual Reality.

Having published the report as a provocation, we are now inviting others to get in touch, and continue the discussion. Whether it’s through better or fewer rip-outs, the goal is that over the life of our office buildings we reduce our impact on the climate.

Craig Robertson is head of sustainability and Ella Smith is a building performance analyst at AHMM

Read the full report at:


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