To reduce the substantial contribution of the built environment to energy consumption and carbon dioxide emissions, the new ‘Part L: Conservation of Fuel and Power’ of the Building Regulations for England and Wales came into force in April, 2006. As a result, the design of all new-build and refurbished buildings must comply with ‘Target Carbon Emissions Rates’. Apart from the purely practical implications of compliance, the new Part L has prompted interesting questions concerning procurement and the impact on design and construction teams. The so-called ‘traditional method’ of procurement presupposes that designs are, in theory, completed before contractor involvement. In contrast, Design-and-Build (of which there has been a marked increase) relies upon a certain amount of concurrency in design, procurement and construction. In the light of the new Part L requirements, this presents a risk, particularly in the case of environmentally sensitive buildings, where the necessary design iterations are at odds with the contractor's time and cost incentives. These concerns have prompted the current investigation. Although the challenges relate to buildings as a whole, particular attention was paid to façades, as they represent an especially sensitive element. Data collection was by semi-structured interviews from a sample representing a selection of large construction companies, architectural practices and building performance consultants. The research framework was published in the proceedings of the 2007 Conference of the Association of Researchers in Construction Management where it was selected for discussion in an industry-wide forum, and the current paper reflects this response and develops the topic further.