West Kensington Office Refurbishment & Extension is the transformation of a 1980s office building in West Kensington, London, combining the refurbishment of existing workspace with a new rooftop extension. Satish Jassal Architects delivered the project in phases, allowing the building to remain occupied while upgrading the existing floors with new services, flexible office layouts and improved environmental performance. A new mansard roof extension adds approximately 2,500 sq ft of additional office space, carefully designed to respond to the surrounding conservation area and the proportions of the existing building. Prefabricated construction elements were used to reduce disruption and minimise time on site. The rooftop extension is clad in pre-oxidised copper shingles, with projecting oak-framed windows bringing natural light deep into the new workspace and giving the addition a distinctive contemporary character. The project demonstrates our experience as architects in West Kensington and London, specialising in office refurbishment, rooftop extensions, commercial architecture, conservation area projects and the creative reuse and adaptation of existing buildings.