The clients approached us to design a loft extension and full fabric-first retrofit of their mid-terrace house in Walthamstow. Their existing house suffers from overheating due to the rear of the house being south facing with large expanses of glass and poor construction. One of their top priorities is to manage solar gain and improve the thermal comfort of their home alongside making sustainable improvements such as installing an air-source heat pump, woodfibre insultation and a sedum roof. The existing kitchen extension will be retained and the external facade will be upgraded with timber cladding.