Carpet is the single highest-emitting build material used in events – and 78% of it is used only once, according to new data from isla, one of the UK’s leading independent bodies for sustainability within events.

The finding is one of several results from A Closer Look: Materials, the first in a new series of data-led reports from isla, drawn from more than 6,400 materials entries logged across 789 events in 2025 on TRACE, isla’s carbon measurement platform.

isla: Venues have a significant, largely unexplored role to play in breaking the single-use norm

In graphics, non-PVC standard banners carry the highest total emissions – making carpet and banners the two materials isla recommends as the starting point for any reduction programme. Despite carpet being widely regarded as a practical necessity, the report argues it deserves more strategic scrutiny, and that venues have a significant, largely explored role to play in breaking the single-use norm.

Across the board, 84% of all materials measured are virgin – newly produced rather than hired, reused or made from recycled content – and 42% of build materials are used only once and then discarded. The total weight of single-use materials recorded in TRACE is 1,229 tonnes. At around £292 a tonne to dispose of, the estimated disposal bill comes to almost half a million pounds – budget spent producing, transporting and then throwing away materials used for (at most) a few days.

On average, events are bringing in 2.7 tonnes of virgin material per event, with 87% of build production materials classified as virgin and only 10% made from more than 50% recycled content.

The report also challenges a common assumption: that materials are a secondary concern compared to travel. With audience travel taken out of the picture, and materials jump to 27% of total event emissions. Remove staff travel too, and materials represent 31% of an event’s entire controllable footprint. This, isla reports, makes it the single largest category that organisers can directly act on.

The report also sets out a practical three-part framework for tackling materials: reduce overall volume, make smarter design choices, and think about what happens to materials at the end of their life before the event begins rather than after. It also introduces a scoring model that weighs up five factors: how much a material contributes to emissions, how easy it is to change, how viable that change is long-term, how much data is available, and how much control organisers actually have over it.

Emily Shephard, insights lead at isla, said: “When you dig into the materials data, what stands out isn’t just the scale of the emissions – it’s the volume of waste that’s become normalised and accepted as part of doing business. Nearly half of build materials are used once and thrown away, a shocking stat for circularity efforts, emissions reductions, as well as a significant financial burden. That’s a clear call to action and somewhere to focus for anyone making design and build decisions.”

The report is free to download here.