The ‘Kern Süd’ in Uster clearly shows that the best way to meet urban living and working requirements is with a sustainable energy supply. The newly designed residential and commercial quarter includes three 5- to 7-storey residential units. In order to meet the extensive energy requirement of 872 MWh, the developers opted for the use of energy-efficient geothermal heat. The drilling work was carried out in restricted space in the heart of the city by Heim Bohrtechnik. The JANSEN vertex high-pressure PN30 geothermal probes were successfully installed at a depth of 400 m.