Aim: We will present our ongoing experiments on home makeovers of private rooms of people with intellectual disabilities and severe behavioural problems living in a Dutch long-term care facility to demonstrate that a tailored environment contributes to a better quality of life. Background: Eight years ago, the transformation of ‘D’s room’ changed the life of D, a person with severe intellectual disabilities and behavioural problems. This was done in close collaboration between a Dutch care facility and an architect. It is because of D’s drastically and positively changed behaviour that the care facility decided to transform the physical environment of twelve of its most vulnerable patients and to study the impact on patients and staff. Methods: A project is started to transform the rooms within a four-year period and to open up a knowledge platform. To streamline and replicate the transformation process, it is broken down into ten steps. Part one of the multiple case study consists of a narrative representation of the four completed room transformations. Results: An open cooperation between caregivers, architect, and family seemed to be very important in the process. The study shows a reduction in behavioural problems of patients and improved working conditions. Conclusions: A new approach to the living environment of people with intellectual disabilities and severe behavioural problems in long-term care can have remarkable results for patients and staff. It is important to raise public awareness of the importance of a suitable living environment as an integral part of disability care.