Movable sun protection

Modern facade constructions combine sun protection with harmonious lighting conditions. In an office building in Austria, PLEXIGLAS® Satinice allows daylight in while simultaneously protecting against the sun’s radiation.

Anyone passing Haus am Milsertor in the small Tyrolean town of Hall will notice the bespoke folding sliding shutters straight away. When open, the translucent white panels extend outwards like flags; closed, they cover the full-length glass of the building’s facade like a second skin, creating pleasantly soft light in the offices within.

Compartmentalized facade structure

The folding sliding shutters envelop the corners of the building which is home to the Private Banking division of Raiffeisen Regionalbank Hall in Tyrol. The elements cover all three floors on one side of the building, as well as two floors on the entrance side. Stripe-like horizontal concrete bars break up the delicate structure, creating a symmetric appearance. “We chose this simple basic shape for Haus am Milsertor, optically highlighting the central areas and softening the corners,” says planner Walter Niedrist from the architect firm ao-architekten ZT-GmbH in Innsbruck.

High static quality

The architect’s grand idea was put into practice by Colt International GmbH, a company which has already implemented numerous sun protection projects worldwide. They convinced the planners to use PLEXIGLAS® rather than sheet metal or fabric for the sliding folding shutters. According to Colt, the brand acrylic glass’ combination of outstanding material properties and comparably low weight made it the ideal choice. The elements need to withstand any weather conditions and extreme fluctuations in temperature, for example, while still maintaining their attractive appearance. Unlike fabric constructions, PLEXIGLAS® also possesses the required static qualities and remains very slim even as a large panel. In this case, the 60 x 60 centimeter sections are just 6 millimeters thick.

Pointed corners

Haus am Milsertor rises from trapezium-shaped foundations. Its pointed corners are equipped with very special sun protection blinds made from PLEXIGLAS® Satinice. When closed, they envelop the building’s facade like a second skin...

The open folding sliding shutters extend outwards, similar to a line of flags

Barely visible from inside

...while when open, they extend outwards like a line of flags and provide an almost unobstructed view from inside the building.

Highlights in the central section

Light-colored, horizontal concrete bars that extend the entire height of the building are a particular highlight in the central section. They form a cohesive unit with the open, transparent zones at the corners of the building.

Close-up of the folding sliding shutters

Motorized control

A unique system was developed specifically for the installation of the PLEXIGLAS® folding sliding shutters. Struts are installed at the end of the shutters. When the shutters open and close, one strut remains rigid while the other moves. They are controlled by a motor.

View of the folding sliding shutters from inside the building

Protection where it is needed

When closed, the folding sliding shutters provide protection against the sun and ensure pleasantly soft light enters the building. When they are open, the shutters have a subtle look and ensure an almost unimpeded view to outside.

Translucence creates pleasant lighting conditions

The PLEXIGLAS® Satinice WH10 DC used also ensures significant, pleasant light diffusion, while the material’s innate UV protection guards against the harmful effects of the sun. As a result, the folding sliding shutters significantly reduce the heat load caused by solar radiation, while their translucence provides pleasant lighting conditions inside the building. Depending on the light conditions, the shutters can be folded in such a way that they appear almost invisible from inside, allowing even more light into the building. In addition, the matte surface of PLEXIGLAS® Satinice prevents any glare around the building, as the folding sliding shutters do not reflect the sun’s rays significantly when closed.

Specially-designed drive system

The biggest challenge facing the specialists from Colt was how to attach the folding sliding shutters to the building. When closed, the entire construction was to enclose the existing building envelope as a secondary facade, like a second skin. To achieve this, Colt went as far as developing a special drive system. It was vital to prevent any water from penetrating the mechanism, despite the high levels of rain and snow in the Hall region.

Each folding sliding shutter is constructed from two out of a total of 1,504 integrated PLEXIGLAS® panels, connected together with specially-produced hinges. Producing the folding sliding shutters took around eight weeks. The result is 18 facade areas, each of which can be adjusted individually, either via the central control or manually. As a result of the compartmentalized facade structure, the dimensions of the building and the number of floors are not immediately obvious. The folding sliding shutters not only function as a translucent sun protection, but also as the building’s second skin.