Since the introduction of steel as a building material in the early twentieth century, its superior performance has challenged conventional wisdom about construction, enabling designs of surprising lightness and span. Steel offered the opportunity to significantly expand buildings vertically and thus emerged as a symbol of the conflict between technological progress and the architectural ideal. More recently, the use of exposed steel elements in modern architecture ushered in a rediscovery of buildings' metamorphoses. Building Additions in Steel looks at the largely ignored topic of steel additions in architecture and engineering, documenting an ambitious, interdisciplinary research project by architects, engineers, teachers, and students at the Zurich University of Applied Sciences, Institute of Constructive Design. The book offers basic theoretical and technical information on a selection of outstanding steel additions alongside more than 100 illustrations, including plans and photographs. With contributions by Jurg Conzett and Roger Diener, Lorenzo De Chiffre, Yves Dreier, Patric Fischli-Boson, Patric Furrer, Matteo Iannello, Daniel Meyer, Francois Renaud, Astrid Staufer, Daniel Stockhammer, and Martin Tschanz. AUTHORS: Daniel Stockhammer is a teaching and research assistant at the University of Liechtenstein, Institute of Architecture and Planning. Astrid Staufer is an architect, professor at Technische Universitat Vienna, and codirector of the Zurich University of Applied Sciences, Institute of Constructive Design, an interactive hub for teaching and research in building design and construction in Winterthur, Switzerland. Daniel Meyer is a civil engineer and a lecturer at the Zurich University of Applied Sciences, Institute of Constructive Design. Jurg Conzett, dipl. Bauingenieur ETH/SIA (born 1956) studied civil engineering at EPF Lausanne and ETH Zurich. Diploma in 1980. Worked with Peter Zumthor. Since 1988: own engineering office in Chur (Conzett Bronzini Partner). Major projects: Punt da Suransuns, Traversiner Footbridge. Roger Diener, born 1950, is an architect educated at ETH Zurich and EPFL in Lausanne and a principal with Diener & Diener Architects in Basel. He taught as a Professor of Design at EPFL 1987-89 and as a Professor of Architecture and Design at ETH Zurich and at ETH Studio Basel 1999-2015. He has also been a visting professor at Harvard University and at universities in Vienna, Amstardam, and Copenhagen. Lorenzo de Chiffre is a freelance architect and also works as a research and teaching assistant at Vienna University of Technology. He has been working with various architectural firms before, including Carosu St. John Architects in London. Martin Tschanzis is an architect and lecturer for theory and history of architecture at Zurich University of Applied Sciences in Winterthur. 52 colour, 75 b/w illustrations