Research project funded by the Technology Strategy Board (TSB), aiming to the creation of a new software package, under the name 'Butterfly'. This low carbon design and decision tool will simplify and improve decision making at the design stage by incorporating for the first time in one tool the life cycle, fabric, embodied and operational energy and carbon metrics as well as a Code for Sustainable Homes calculator. The project is led by BLP in partnership with Willmott Dixon, UCL Energy Institute and University of Cambridge Centre for Sustainable development.