Scenic views of Vienna through glass

Scenic views of Vienna through glass

Project Reference
08 Jun 2020

New apartment complex Parkapartments Am Belvedere and Hotel Andaz Vienna Am Belvedere, have become a new landmark of Vienna. The architects of the renowned architectural office Renzo Piano designed five buildings with eye-catching facades made of aluminium, ceramics and glass.

Parkapartments Am Belvedere and Hotel Andaz Vienna Am Belvedere

These vertical structures standing on tall, slender ‘piloti’ seem to float above the crowns of the Swiss garden and offer a fantastic view of the historical heritage of Vienna, the Belvedere Palace and St. Stephen's Cathedral. The eye-catching facade made of aluminium, high-quality ceramics clads, and glass is just as prominent as the structure itself. Complex insulating glass meets the high glass engineering requirements in the building physics concept and contributes to the energy efficiency of these new buildings.

When the highest glazing requirements are set, then modern coating technology and specialist knowledge in the field of glass processing should work together perfectly. To achieve design goals, two partners, glass manufacturer Pilkington Deutschland AG and Austrian glass processor Petschenig glastec GmbH, cooperated together from the production and delivery of the basic glass to the manufacture of each individual insulating glass unit.

"Without an insulating glass line with fully automated spacer application, a project with such tight deadlines and quality specifications is practically impossible to manage," says Hanspeter Petschenig, Managing Director of the insulating glass producer. The Austrian glass processor used around 50,000 square metres of basic glass for the façade to create heat-insulating and sound-absorbing as well as fall-protecting high-quality triple glazed insulating glass units.

The Parkapartments Am Belvedere were developed by the SIGNA Group and the Hotel Andaz Vienna Am Belvedere by a joint venture between SIGNA and HYATT Group. The RPBW architects were involved in the planning at an early stage. Renzo Piano sees one of the most important urban planning goals in the fact that suburbs are once again becoming urban centres worth living in. His urban concept for this area takes into account not only visually attractive sight lines and views, but also the negative aspects of the big city such as noise from the nearby train station and Arsenalstrasse. The architect also intended to create a smooth transition to the adjacent Swiss garden.

The solution was to raise the buildings on tall, slender ’piloti’. Seen from the street level, the buildings only begin at a height of between four to six floors above the ground and are therefore above the treetops of the Swiss garden. In addition to the beautiful view and noise reduction, this solution offers space for green open spaces that connect the buildings and bring the Swiss garden visually closer.

The 342 apartments and the 303-room hotel with sky bar, ballroom and conference area are spread over five towers with polygonal floor plans. The three apartment blocks contain more than 60 different apartment types. Floor-to-ceiling windows as well as loggias, balconies or terraces give the apartments the desired brightness and spaciousness. The windows cannot be opened for security reasons, but they do have ventilation sashes. Underfloor heating and ceiling cooling systems, which are fed via district heating and cooling, ensure an optimal climate.

Parkapartments Am Belvedere and Hotel Andaz Vienna Am BelvedereGlass, aluminium and a light grey ceramic stone determine the appearance of the façade. The horizontally and vertically installed ceramic stone breaks up the closed window front and gives it a certain depth. The 28,000 square metre suspended façade system was designed as an element façade. Strabag Metallica, the company responsible for the façade, installed 5,600 elements, including 1,100 triple glazed units, 48,000 corrugated sheets and 60,000 grey glazed ceramic strips. 

Good thermal insulation and high sound insulation as well as protection against falling through glazing were the basic requirements that were set for floor-to-ceiling high glazing. Due to the high noise level caused by the railway station and main roads, the sound reduction requirements were in some cases up to 52 dB. Triple glazed units have been made of Pilkington Optiphon™ Therm S3 laminated acoustic safety glass with low emissivity coating as an external pane and where fall protection was required an internal pane have been made of Pilkington Optilam™ Therm S3 laminated safety glass with low-emissivity coating. A large part of triple glazed units has been made of Pilkington Optitherm™ S3 toughened by Petschenig glastec. The triple glazed units achieve Ug-values of 0.6 W/m2K with a light transmission of around 70% and total energy transmittance of 46%.

The ground floor and the penthouse apartments on the upper floors were also glazed with triple insulating glass units made of low-emissivity glass Pilkington Optitherm™ S3.

The building corners have been glazed with the curved insulating glass units. They have been made of toughenable low-e products from Pilkington Optitherm™ family. Flintermann GmbH manufactured a large number of curved triple-glazed insulating glass units, each consisting of five large-format panes, as well as monolithic laminated safety glass, in some areas with SentryGlas+ film. The bending specialists from Salzbergen were the only glass processors to accept the challenge of producing panes with a very narrow central area according to the architects' wishes. Bending tests were carried out under great time pressure during the ongoing construction process until the solution was found and production started. 

The realization of the Parkapartments Am Belvedere and Hotel Andaz Vienna Am Belvedere in Vienna excellently shows that technical complexity and compliance with the highest quality standards, taking into account tight dates and costs, can only succeed if all project participants work closely together in collaboration and rigorous project management.

Client: SIGNA Group; www.signa.at

Design: Renzo Piano Building Workshop in cooperation with NMPB Architects ZT GmbH (Wien); www.rpbw.com 

Project management: Thorsten Sahlmann, RPBW Paris

Architects Execution: NMPB Architekten ZT GmbH, Wien; www.nmpb.at

Project management/local construction supervision: Pro Projekt Wien; www.proprojekt.at 

Facade: STRABAG AG, Abteilung Fassade Metallica; www.metallica.strabag.at 

Mullion and transom façade: AluSommer GmbH; www.alusommer.at 

Basic glass: Pilkington Deutschland AG;  www.pilkington.de 

Insulated glass units: Petschenig glastec GmbH; www.petschenig.com 

Curved glass: Flintermann GmbH; www.flintermann-glasveredelung.de 

Photography: www.architekturphoto.at