SEG Apartment Tower 

Adjacent to the Alte Donau metro station, the SEG Apartment Tower is situated in Vienna’s Donau City, a contemporary development at the eastern end of the Donaustadt district.

The 60 m high SEG Tower includes 70 apartments, offices and practices on 25 floors. The complete arrangement captivates due to its striking height and its quality of space. On the one hand the concept of the tower is based on the idea to merge two houses, one on top of the other, to get a common space at the intersection. This common space — called a sky-lobby — is then used for the accommodation of a venue, a playground, a ​“teleworking café” and a sundeck. On the other hand the concept of the so-called climate facade was developed, which is the linking and surrounding element between the two components.

All apartments (ranging from 55 m² to 130 m²) are influenced by the loft concept with an open plan and no load-bearing walls. This enables a flexible layout of all the units. A concierge located in the two-floor high entrance lobby provides optimal service for the inhabitants.

The Passive Energy Concept

Together with the ​“air-box” on top of the roof and the circulation core (as heat accumulator), the glass facade regulates the cooling of the apartments in summer and the heating in winter. This well calculated system offers a higher level of comfort during hot weather and a minimizing of costs during the heating period. Thus, the initial investment for the energy system was lower, and the amortisation period considerably shortened.

Facing southeast and southwest, the glass facade is the medium through which thermal energy is stored as radiant energy potential during winter, spring and autumn. The thermal energy produced during daylight hours is supplied to a thermal reservoir unit located inside the building. This creates a milder, more equitable room climate in areas behind the climate facade. The exploitation of passive solar energy leads to a considerable reduction of energy consumption: this is due to the stabilisation of the temperature difference between the interior living space and the loggia area, and the direct supply of energy to the apartments, coming from the thermal reservoir inside the core area of the building.

The reinforced concrete shaft of the building provides central thermal mass.

To expedite the energy exchange process, it is equipped with heat exchange surfaces, also made of reinforced concrete. To guarantee heat exchange between the loggias and the climate facade, air circulation between the two systems will be provided mechanically, and additionally impacted by the ventilators in the thermal mass shaft.