The UK built environment has a high proportion of buildings on the verge of becoming stranded assets as environmental targets tighten. The scale of the challenge to upgrade buildings of this type is huge. How can a project balance both a retrofit led investment and deliver the potential for increased rental values? At 300 Gray’s Inn Road the team have embedded carbon analysis whilst interrogating different options to provide the client with detailed guidance, facilitating an accurate design-making process and a route map to an environmentally and commercially viable scheme.