Building measures in existing buildings is of crucial importance for the path to a climate-neutral future. Nevertheless, continuing to build not only requires planners to take great care in planning, but also to be patient and imaginative when dealing with unforeseeable problems. This book chronicles outstanding quality of living conditions that can be created through alterations and conversions, refurbishments, renovations and modernisations carried out on existing buildings. It shows 26 exciting best practice projects from the years 2017 to 2023 - from a converted church in London to a multi-storey car park extension in Cologne. Detailed drawings at a 1:20 scale provide a precise picture of each of the construction solutions along with floor plans and sections.