The numbers, including the ones we are not proud of

Waste

This is where offsite manufacture wins clearly. Materials arrive on a schedule, are cut on a jig and the offcuts are sorted at the station where they are made. Our factory waste to landfill was 1.8% by weight last year, against a UK construction average that sits well into double figures.

The comparison we publish, −78% against traditional build, comes from two of our own projects where the client also built a near-identical traditional block and shared their waste transfer data with us. It is two data points, not a study, and we describe it that way.

Embodied carbon

A steel-framed volumetric module is not inherently lower in embodied carbon than a traditional building. The frame is steel and there is more of it, because every module needs to survive being craned. What offsets it is less waste, less transport of wet trades, and a much longer design life with the option of relocation.

Our environmental product declaration to EN 15804 is on the specifiers page. It is a real EPD with a real A1–A5 figure, and it will not always be the lowest number you are shown.

Operational performance

Here the factory helps again. Airtightness is a workmanship problem, and workmanship is more consistent indoors on a line than outdoors in February. We test every module and 91% of completed buildings reach EPC A without a bespoke specification.

End of life

Modules are bolted, not cast, so they can be unbolted. We have relocated 64 modules to second sites, mostly education buildings that moved when a school reorganised. That is a small number against what we have built, and we would like it to be larger.