A generous feeling of space: From garage door to premium facade

In downtown Zurich a new building complex incorporating a 70 metre high residential tower with a punctuated facade was completed last year in which some of the windows can be opened all the way without encroaching on indoor space. The large-scale, electronically-controlled windows tilt up and back across the ceiling to open up the apartments to the outside and provide residents of the Löwenbräu Black high-rise with spectacular views of the Swiss city. When open, these up-and-over windows provide a generous feeling of space as their profiles do not interfere with the field of vision. Architects: Gigon/Guyer und atelier ww
Location: Löwenbräu Areal, Limmatstrasse 268, 8005 Zurich, Switzerland

The 20-storey tower block, which is clad in corrugated ceramic wall tiles in black, is part of a composition involving various buildings whose appearance reflects the differing uses to which the site of the former Löwenbräu brewery has been put. The high-rise stands in contrast to the museum centre at the site, a four-storey building in exposed concrete that accommodates Zurich Museum of Fine Art, the Migros Museum for Contemporary Art and various galleries, while the nine-story office building at the complex is faced in shiny red ceramic tiles in reference to the colour of the site's listed brick buildings while differing from their matte facades in texture. The 70 metre high residential tower, which offers high-grade apartments between 98 and 320 sqm in size, juts out nine metres from its L-shaped, six-floor base over the historical building at its feet.

To not distract from the archetypal building's powerful impact, the architects at Gigon/Guyer and Atelier WW found it particularly important to avoid differentiation in its grid façade – in other words, the fixed glazing and the operable windows were to be virtually indistinguishable from the exterior. The punch windows with a total area of 3,800 sqm are designed as composite windows and on their left or right feature a 120 mm wide vent that opens up 90 degrees for natural ventilation of the rooms, thus obviating the need for an air conditioning system. The development and execution of the 3,900 sqm facade was entrusted to Josef Gartner GmbH. The tiles were completely glazed – i.e. including the edges and joints – after firing.

In this upscale downtown residential development, the architects cast around for a way of doing without balconies and loggia, and wanted entire glass elements to open without the view being impeded by window profiles, etc. This ruled out conventional solutions such as awning-type, sliding and folding windows. In response, Gartner came up with the new tilt-lift mechanism, which enables the openable glass elements to glide upwards and back across the ceiling like garage doors, resulting in a particularly spatial effect. The occupants are thus provided unimpaired views and when the windows are open, the apartments have the feel of huge balconies, so to speak.  A textile screen let into the box-type windows provides protection from the sun and glare, and when windows elements are open an additional exterior screen can be let down.

Reporty by Klaus Lother (Managing director of Josef Gartner AG, Gundelfingen) and Frank Kaltenbach.
An extended documentation can be found in DETAIL 7+8/2014 "Façades".