Hotel Boscolo

Hotel Boscolo
Prague
[ 185 ]

accomplishment 2002–2003
investor AGAGA
architect DAM architects
type of construction complete external envelope
type of building hotel
general contractor PSJ holding
project volume of the facade 0–1,9 mil. EUR

Sipral supplied non-standard glazed and steel structures, a large gilt awning and several small awnings for the side entrances of this neo-renaissance building on Senovážné náměstí, a former Hypoteční bank in disrepair that was reconstructed and converted into a luxury hotel by the Boscolo Italian hotel chain. The project, which was characterized by the pursuit of high quality and accurate workmanship in every detail, earned the Stavba roku 2004 (Building of Year for 2004) prize. Sipral supplied glass rotule facades measuring 1167 square meters with screen printing in front of the new hotel wing erected in the yard and connected to the existing building. Single hardened glass panes 12 mm thick are anchored to stainless point rotules embedded in drilled holes and which are separated from the external surface’s panels by a 0.6-meter gap. The extremely large dimensions of the glass panes – 4.15 x 1.64 meters – and the need for full-size screen printing put the current technologies to their limits: although every care was paid to the manufacturing that took place outside the Czech Republic, the screen printing was defective on the edges of the glass panes. The manufacturing of the glass panes was also complicated by the architects´ requirements to maintain diversity in the screen printing. Each of the eight glass panes was printed differently, with each part forming leafage in a “tree” in an imaginary holt, the English translation of the Italian word ”boscolo“. Sipral also supplied non-standard steel structures for the new entrance into the congress center, including the semi-structural façade of the entrance and foyer. The new entrance hall with a 15 x 6.5 meter plan and an attic 5.3 meters high, is located next to the old building which had a symmetrical layout; its glass facades separate the east yard from the street. It also offers a barrier-free entrance into the hotel. The hall’s main supporting structure consists of a monolithic slab 0.25 meters thick that is supported by columns welded of hollow steel profiles with continuous girders. The front and rear facades of the entrances form parts of the structure and consist of double-glazed units that are printed with leaves, entrance sliding and emergency doors. An all-glass door space was erected in front of the front façade, which is equipped with an automatically operated door. The project’s biggest challenge was the 7.6 x 10.6 meter gilt awning above the entrance of the congress center. The awning is attached only to two points and partly covers the roof of the entrance hall at a length of 3.7 meters; the remaining 6.9 meters of the structure is projected in front of the façade. Another considerable problem was that the steel soffit welded to the steel supporting structure had to be completely flat so that the subsequent gilding revealed no deformations. Sheets 6 mm thick with 8x3cm laser-cut holes, through which light rays are to be projected, had to be welded to the supporting steel structures, ground and prepared for gilting on the construction site. For this purpose, a special mounting method had to be applied. The entire awning weighed a remarkable 11 tons. The awning was rotated and installed with two cranes. The 73 square meter awning was gilded with 24-carat sheet gold during a cold period in January by a Czech subcontractor successfully drawing from experience with gilding interiors in Abu Dhabi.