In the UK there is, as part of the EU carbon reduction commitment, a legally enforceable target to reduce the carbon impact of the built environment by 80% by 2050 as shown in Figure 1 below. As a result as consultants we have been exploring the tools and processes we need to deliver on this commitment. This paper looks at the state of the art and considers how the tools and the parallel process of design and construction need to evolve to allow the industry to accuratelypredict and control carbon in the built environment.