119 Ebury Street is the first listed building in the UK to achieve BREEAM Outstanding for its proposed design, the highest possible rating. The scheme is a highly sustainable refurbishment within a heritage context, comprising a change of use from a hotel to create three residential duplexes, including a new mansard roof and remodelling of the rear extension. The scheme emphasises the integration of sustainable solutions into a Grade II listed property with a measured approach which is both sensitive and appropriate to the historic fabric. Through the application of the maximum possible efficient engineering systems and low carbon technologies, this “exemplar” sustainable retrofit project meets the government’s 2050 national carbon reduction target of 80%. Key objective of this project is to engage with resident end-users to interact with the sustainable initiatives provided, motivate them to achieve end-use energy efficiency and still provide high quality residential accommodation. A two-year post occupancy monitoring programme is used as a unique opportunity to allow for a thorough understanding of the measures employed and help to guide on future refurbishment projects by sharing information with local authorities and statutory bodies.