The administration building of the “Dachverbandes der öster. Sozialversicherung”in Wien, built at the end of the Seventies, has recently undergone a general renovation.
The building has 16 floors above ground and a total GFA of approx. 22,600 m2 and, thanks to the set of interventions, was certified with "EnerPHit Plus" and "klimaaktiv Gold" (996 out of 1000 points) after the renovation. In addition to the renovation, also an annex building with 7 floors above ground was demolished and replaced by a new building where a conference hall and a restaurant were placed.
The architects Chaix & Morel et associés (Paris) and Arch. DI Christian Pichler (Vienna) emerged as the winners from an international competition, thanks to the innovative solution for integrating the photovoltaic systems (a total of 148.24 kWp) on the flat roofs of the main building as an essential architectural feature and extension designed as a “fifth facade”.
A very good thermal renovation, a highly efficient and demand-oriented building and house technology was implemented.
Also a special attention was devoted to the user impact on energy consumption, hanks to an efficient equipment for lighting and appliances. In fact, the users are considered as an essential energetic factor was also carried out optimally, e.g. only monitors with a power demand of 9 W (7.5 W in economy mode) are used and the workplace lighting is provided by particularly economical LED free-standing lamps (137 lm / W).
By equipping the building and building services with energy-efficient components, not only the operating costs but also the internal waste heat that generates cooling and thus the required cooling energy are reduced.
The building also has a night ventilation system for the building cores, which further reduces the use of cooling energy for air conditioning, because the very effective method of gravity ventilation for lowering the temperature of the building cores only requires a minimal amount of energy.
The “umbrella association of Austrian social insurance” is an important and central public institution. The latest requirements for energy efficiency, building comfort and office architecture were implemented at its location and a model was created for the implementation of energy-generating office buildings.
With the seminar and conference rooms for a total of 494 people and the restaurant, the location is also a public building. With this aspect in connection with the perfectly visible PV system and the building technology that visitors can see, the umbrella organization makes a major contribution to the communication of energy-efficient use of renewable energy.
Flexible working environments and meeting rooms, good daylight illumination right into the interior corridor areas, as well as a contemporary appearance of the entire ensemble with new, green open spaces and open forecourt represent the added value of this unusual general renovation in addition to the aspects of sustainability.
Concerning the envelope, the façade is made of elements with insulated sheet metal panels with an overall a thermal transmittance of 0.26 W/(m2 K), and the glazing system has an aluminum frame and Triple glazing with argon filling and laminated safety glass in the front, with a U-value = 0.53 W/(m2K) and a solar transmittance of 33%. The roof present a large photovoltaic plant and is highly insulated with EPS and present a thermal transmittance of 0.11 W/(m2K ).
The heating is supplied by the district heating system and the emission system is both with radiant ceilings and through the ventilation system, that also integrates heat recovery. The domestic hot water is produced by decentralized boilers integrating storage that are installed in different area of the building.
According to the PHPP evaluation the annual heating demand accounts for 19 kWh /(m2a) and the heating load is 16 W/m2.The primary energy requirement for the office building in the specific context accounts for 76 kWh /(m2a ), including the primary energy for heating, domestic hot water, household electricity and auxiliary electricity calculated according to PHPP, and the building reaches the value of 49 kWh /(m2a ). The energy generated by the PV system accounts for 66 kWh /(m2a ).
More information in German and pictures are available here: