The Metropolitan building in Warsaw, with Pilkington glass products, was announced the 2003 World’s Best Business Centre (MIPIM International Property Market in Cannes).
The pentagonal shaped Metropolitan building in Warsaw spans between Wierzbowa and Moliera streets. It was designed by the world-famous architect, Lord Norman Foster. The ground floor construction produces an impression of the building suspended over the square. There are six levels of office blocks with the top level retreated against the façade to making the building seem lower than it really is. Inside there is a circle shaped courtyard 50 meters in diameter, with three openings to the outside.
Selection of glazing
The buildings outer façade has been designed for the best use of natural light. Transparent glazing in the public courtyard creates a feel for larger space. For the inner and outer façades, the designers used IGUs spanning the length of the building. The flange between levels, reduced almost to the construction thickness of floors, eliminated the use of glass spandrels and each solid of the building is within one of the six metal rings. This arrangement forced the use of sophisticated technological solutions for the glass and aluminium wall, as granite blocks were mounted in the column area in the entire façade. This large glazing without any internal balustrades is able to withstand high wind pressure. The measurements of the outer façade panels are 3200 mm in height by 1500 mm in width depending on the position (rounded corners were built with flat glass).
An additional project requirement was to increase the noise insulation for the entire building. The building was glazed with Pilkington Insulight™ Phon IGUs which consist of 10 mm Pilkington Optitherm™ SN T on the outside, 16 mm space filled with argon and Pilkington Optiphon™ 10.8 on the inside. Pilkington Optitherm™ SN T ensures good thermal insulation while maximum transparency and neutral façade colour are maintained. Pilkington Optiphon™, when combined with a thick monolithic external plate, forms an amazingly efficient acoustic barrier for tenants in the Metropolitan building.
A steel frame provides the necessary fire protection between floors. The entire arrangement is hidden behind the suspended ceiling and is not visible from inside the building. Two 5 mm colourless Pilkington Optifloat™ Clear T glass (toughened) with special soundproof foil was used as the inner layer of the laminate to significantly increase the resistance of the glass to temperature changes and risk of thermal stress. To prevent any potential post-toughening deformations plates were coupled during the lamination process. The solution came in the form of a suggestion from the Pilkington Poland Technical Office. Repeated analyses demonstrated the need to use toughened glass as the inner layer of the laminate. This significantly increased the resistance of the glass to temperature changes and eliminated the risk of thermal breakage. As a result, unprecedented solutions were applied. The structure of the internal plate was modified by the use of two panes of 5 mm Pilkington Optifloat™ Clear T (toughened), laminated with specific acoustic PVB.
In terms of manufacturing processes, non-standard solutions as the response to designers’ expectations required implementation of a special production regime. Toughening of large thin glass panels (3200 mm x 1500 mm) may reveal significant post-toughening deformations and eventually cause problems with lamination of these “twisted” plates. This was yet another occasion when Pilkington Poland’s expertise proved to be very useful. First, deformations on the toughened glass were significantly minimised – as much as twice below applicable standards – and secondly, a special system for marking the plates was developed, to match them into pairs during the lamination process. This allowed achieving quality comparable to standard laminated glass from the production line.
A very exciting challenge was the use of opaque glass at the entrance doors and in gate passages to the courtyard. The designer's idea was to use snow-white glass cladding. Tests proved that the best option was to use low iron Pilkington Optiwhite™ glass, covered with white ceramic enamel. The majority of opaque components were bonded to aluminium profiles and the entire arrangement had to be flawlessly white.
With the use of new material combinations, not applied in any previous development, the architect’s expectations could be met.
The seven storey high inner façade is entirely glazed and surrounds the circle shaped courtyard. Full height IGUs from floor to ceiling were also used for this façade. The visible difference is that there are no granite ribs. However, differences that are not visible at first glance also exist: glass fitting method and additional finishing were modified. While the outer façade IGUs were fitted around their four edges, the inner facade IGUs were only supported on their two horizontal edges.
The impression of complete transparency was important from an office perspective. Ceramic printing was therefore applied on the outer panes as a safety measure to indicate where the office floors ended. The façade from the courtyard was glazed with Pilkington Insulight™ Phon IGUs made of 10 mm Pilkington Optitherm™ SN T glass with vertical ceramic print, 20 mm space filled with air and Pilkington Optiphon™ 10.8, similar to the outer facade.
“For the entire facade more than 10,000 m² of glass as IGUs and nearly 1,000 m² of Pilkington Optiwhite™ spandrels were used”, said Piotr Oleszynski, project manager, Pilkington IGP. The building was completed and opened to the public in 2003.
* Pilkington Optitherm™ SN has been discontinued and instead we recommend the use of Pilkington Optitherm™ S3 or Pilkington Optitherm™ S1A - low emissivity glass with improved performance.