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van Vollenhovenflat

Zeist, Netherlands

Short information

Building category
Windows, Façades, Sliding systems, Security
AWS 65, USC 65, ASS 70 FD
Zeist, Netherlands
Frowijn de Roos
Kremers Aluminium BV


Project details

Project description

The modernized apartment block “Torenflat” in Zeist received two awards: Firstly, The Benelux Aluminum Award 2009 in the category residential renovation. Secondly it convinced the high-profile jury of the European Aluminum Award (EAA) for energy efficient buildings. The building was clad with modified profiles from the Schüco USC 65, ASS 70 FD und AWS 65 series and now saves over 290,000 kg of CO2 per year.

The “Torenflat” project in Zeist, 5 km east of Utrecht, is a very large, 19 story, residential building with 484 apartments. The scale of the block built in 1974 has almost unimaginable dimensions: 108 m long, 27 m wide and 58 m high. Around 1,100 people in total live in the east and west facing apartments, which provided the architects, Frowijn de Roos Architecten from Bilthoven, with a particular challenge. They did not only have to find a high quality architectonic and energy saving solution for the 15,500 m² façade, the work also had to be carried out during normal building operation, causing as little disruption to residents as possible.

Fortunately for the architects, the apartment entrances were located centrally in the building and therefore access to the apartments was not impeded in any way by the façade refurbishment. To minimize noise during the building phase, the architects chose a façade system that required the least number of holes to be drilled into the existing concrete structure.

The new façade, who’s special profiles were developed by the architects in close collaboration with the façade contractor (Kremers Aluminium from Tilburg, Netherlands) and Schüco, could be easily fixed to the face of the existing structure with just 3 fixing points per unit. Fortunately, the fixing holes for the former balcony balustrade could be used for the new façade assembly.

Prior to the development of the special profiles and to check critical fixing points, a 25 m², 1 to 1 sample façade was preassembled in Schüco’s Façade workshop: This “test façade” was a great help to everyone involved in the project, in finding the optimal solution for the modification of the profiles.

A façade to prevent heat loss

The new façade envelopes the building like a “warm jacket”. The pre-fabricated elements of the aluminum façade eliminate thermal bridging and the aged appearance of the building complex has been dramatically changed. Although the new look is very different from the “layered-structure” of the existing building, the floors of the building are still readable in the new façade. The architects have given the building a monolithic character, which is visually loosened up through the subtle nuances of the opaque spandrel panels – from dark red to white-pink rising from the ground to the roof.

The speed and logistics of the façade refurbishment were impressive: With two mobile cranes lifting the pre-fabricated façade elements into position, around 150 - 200 m² of new façade could be installed in a single day.

Delighted jury members

“The prefab aluminum façade units were extremely well suited... An apartment was given a new skin in one working day. It combines minimal investment with maximum social economic impact. An outstanding performance and a model for the future renovation of energy efficient apartment buildings of this type all over the world." This was the verdict of the European Aluminum Awards jury, who chose this project as winner in the category Energy Efficient Housing 2009.

Improved standard of living for the entire neighborhood

The tenants who were largely skeptical at the start of the project are now convinced by it: The new façade has significantly improved the level of comfort in the building. The homogenous façade has turned former balconies into loggias that can be used all year round, increasing the living space in each of the apartments. The improvement in living standards has also had a positive effect for the owner: Before the refurbishment, there was a 33 % change in tenants per year. This frequency has now fallen to under 13 %.

The decision to refurbish the building complex has had an impact on the development of the entire neighborhood. In addition to the refurbishment of the “Torenflat” block itself, a new 2000 m² extension, also planned by Frowijn de Roos Architecten, is now home to a healthcare centre and serves as the new entrance to the apartment block. In this two story building there is a dispensing chemist, physicians, physiotherapists and a social welfare centre that is open to all the residents of Zeist. The “Torenflat” project sets a wide reaching and pioneering standard – energy saving, economic and social.

Façade system UCS 65

For the new façade of the Torenflat project, modified profiles were used from the USC 65 series. The thoroughly tested and highly flexible façade system solution, which is also available as USC 65 HI (High Insulation), allows considerable design freedom as well as optimal adaptation to the specific conditions of a project like for instance Torenflat. The USC 65.HI system has slim profiles of up to 65 mm and a variety of architecturally interesting design variations. A comprehensive range of accessories makes the efficient realization of various solutions for modular façades possible.