A timber based attic extension system for sustainable urban densification

The growth of metropolitan areas is progressing worldwide. According to recent projections, the city of Vienna will grow by 250,000 inhabitants and reach a total of 2 million inhabitants by 2030. Supplementary residential spaces have to be developed - not only by creating new urban quarters, but also through refurbishment and urban densification. Most urban development strategies include attic extensions as an important means to increase urban density. Due to their low housing density, Vienna's municipality buildings ("Gemeindebauten") of the 1950s to 1970s seem especially suitable for such measures. Using timber as a regionally available and environmentally sustainable material provides additional ecological and economic advantages. Our objective is the development of a system for attic extensions based on industrially prefabricated timber elements with integrated renewable energy systems. This system shall facilitate large-scale urban densification in Vienna - and elsewhere.