Cement is responsible for most of the carbon in a concrete wall. Over the last five years we have changed how we specify it on every project.
What we changed
- Slag and calcined clay replace up to half of the cement
- Recycled aggregate in all non-exposed concrete
- Thinner slabs with ribbed soffits where spans allow
- Concrete only where it carries load, stores heat or meets the ground
The greenest concrete is the wall you decided not to build.Ada Okafor
What it looks like
Low cement mixes are slightly darker and cure more slowly. We plan for both: board-marked surfaces hide small colour shifts, and the programme allows an extra week before striking the formwork.
