The sustainable renovation of older buildings involves more than just an improvement of their energy footprint – and it is due to the complexity of the issue why architects are destined to take on this task. The book, “Energy efficiency refurbishments”, was written by architects for architects. It shows how design, construction and systems engineering carried out during the renovation of diverse types of buildings fit together. The authors present the basics of indoor and outdoor environments, energy-efficient balancing, ecology and economic viability. Aided by countless illustrations of design details, they discuss issues such as thermal insulation and the proper use of daylight as well as heating and ventilation. Detailed analyses of a residential building and a non-residential building help illustrate how individual issues are integrated into the overall architectural context.