Gilmour’s Close is a 4 storey, 19th Century stone tenement, with commercial ground floor, located in the World Heritage site of Edinburgh’s Grassmarket. Refurbishment of this building was completed by Assist Architects, in 2008, to provide social rented and supported housing for Hillcrest Housing Association. In the refurbishment process Assist sought not only to conserve the historic aspects of this Category B listed structure but also to incorporate low energy principles to the design in the form of ground source heating, passive solar strategies, mechanical ventilation with heat recovery (MVHR) and upgrade of the fabric’s thermal performance by internal lining. This project aims to asses the performance of this development in terms of energy use and user experience, through a 3 week monitoring process and subsequent analysis of the small office space within the development and 5 individual dwellings (2 mainstream social rented and 3 supported).