Life underground

The growing population, increasing housing demand, and rising land sealing are straining the environment and climate. CO₂ emissions rise, air quality worsens, and natural spaces disappear. Using underground spaces offers a solution: shorter distances, stable temperatures, and longer-lasting buildings. However, challenges like lighting, ventilation, and public acceptance remain. Vienna already has many unused underground spaces, such as parking areas beneath Volivpark. This study explores how to make them usable without reducing quality of life.

This work presents an alternative approach to reducing land sealing by developing an underground building. The prominent location directly in front of the Votive Church posed a particular challenge. By placing the building underground, the visual axis to the city centre is preserved, while above-ground green spaces and large existing trees are protected. Recreational and meeting spaces are retained and extended to the lower levels. The concept utilises underground courtyard houses to create residential and public spaces. This architecture made it possible to utilise the space efficiently and achieve a floor area ratio of 1.2, even though only two storeys are available. Different utilisation scenarios were tested to demonstrate the functionality of underground spaces. Flexible elements make it possible to adapt to changing user requirements. Even if complete unsealing cannot be achieved, shifting the sealing to deeper soil layers represents a significant improvement. The heat island effect is reduced and vegetation is preserved. The ground cover is less than one metre and represents a compromise between energy efficiency and daylight penetration. However, a uniform temperature across all seasons would require around four metres, which would have a major impact on construction costs and lighting conditions. The project shows that innovative solutions are often associated with advantages and disadvantages. Nevertheless, it is necessary to break new ground in order to respond to the urgent ecological challenges of our time. This underground architecture offers a sustainable way of making urban densification environmentally friendly and combining quality of life with resource conservation.