In just three years, the number of inhabitants in Vienna has increased by just under 100.000 and demand for housing is rising. Despite new construction projects on the outskirts of the city, there is great demand for high-quality apartments in the city centre. The main focus of this thesis is not the expansion of Vienna in peripheral areas, but rather concentrates on the existing inner city structures. The building grid or block grid of the Gründerzeit is characterised by buildings that are by very close or too close together. In this context, this usually leads to high levels of congestion, as well as losses in both public and private open spaces. The existing qualities of the Gründerzeit city structure must be identified, used and developed further. In the course of this thesis, planning goals for a modern cityscape are defined, taking into consideration that the city is a process, open to constant development. On the basis of two case studies of Gründerzeit blocks in the second district of Vienna, possibilities for densification and quality enhancement are shown. Here, the focus is on cross-property or cross-block planning, focusing on and formulating general qualities, as well as individual ones.