25 Coleshill Road is a total reinvention of ‘the ugly duckling’ on a street in Teddington, Richmond upon Thames into a sustainable, contemporary detached family home. The clients brief included the reconfiguration of all the internal spaces, a new rear/side extension to incorporate a family area and the addition of new modern dormers to the top floor to improve usability. Importantly for the clients, the design strategy looks to improve the thermal performance of the property significantly with all existing external facades and roofs having new wall insulation and energy use being regulated with the introduction of a new ASHP heating system. The brief requirement to improve the thermal performance of the existing building has allowed us to provide a modern external aesthetic that complements its street setting. The project has delivered a contextual and unique approach that improves the architecture of both the existing dwelling and the street in which it sits.