Yesterday was COP26 Built Environment Day. Engineers have an exciting but daunting role to play in reaching (net) zero carbon buildings and the route is yet to be plotted. At Smith and Wallwork our 10 years of materials tracking is telling us that our sub- and super-structure designs have been achieving LETI 2020 targets for embodied carbon. As a business, we are some way off achieving the 40% reduction required for LETI 2030 (despite all the timber structures we design). How we get there will need a plan and some fundamental changes to our engineering designs.