This keynote presentation tells the story of how a series of catastrophic retrofit failures led to the development of the UK’s domestic retrofit quality assurance system. The system was catalysed by the Each Home Counts review and underpinned by knowledge gained from the Retrofit for the Future programme, including the lessons that most retrofit risks are moisture-related, that retrofit goes wrong at corners, junctions, edges and interfaces, and that ventilation is critical to successful retrofit but is poorly understood. The retrofit standard PAS 2035 and the key role of the Retrofit Coordinator in that standard, are both described.