Can high-rises make a fruitful contribution to making cities more sustainable? Many argue that high-rises deliver positive environmental effects, such as densification, and reduction of traffic and carbon dioxide emissions. But is it really that simple? On closer critical observation many questions arise and are explored in this book. What is the impact of tall buildings on their environment? What are ideal densities? What makes a tall building a success? Do high-rises live up to the claims made for them? How sustainable is a high-rise building? Can it be re-used? How can one reduce the environmental impact of a tower? The first part of the book addresses the meaning of high-rise for a sustainable city and asks when urban form can be considered as 'sustainable'. The second part focuses on transformation and area development and the processes necessary to densify the city and to develop high-rise buildings. The main question here is if it is possible to develop high-rise projects that energize city life. The book concludes by discussing the design of the buildings themselves as sustainable structures, contributing to a healthy indoor and outdoor environment, and to a reduction of materials, energy and costs.