The space in big cities has to be used more intensively, but the possibilities are limited. The stacking of functions or the put- ting of industrial premises to new uses are potential strategies. One of the leading options for the future, however, is the use of the flat roofs of residential buildings and office blocks as building sites. Rooftop buildings can intensify the existing city, inject it with new vitality, and diversify the monofunctionality of a neighbourhood.

Preface  7

Aaron Betsky

Introduction  9

Ed Melet, Eric Vreedenburgh

Rooftop construction:

 a dazzling new ground level  17

 Urban transformations 17

 Stacking strategies  22

 Topping up versus rooftop construction  24

 Building methods  28

Utopias  38

Upper city  46

Stacked plots  60

Prefab  74

Extensions  103

Bridges  128

Industrial heritage  140

Roof terraces  160

Penthouses  176

Index of satellite texts  199

Literature  201

The authors  204