PROJECT DETAILS
The Terraced Tower: a unique project with custom-made profile systems
The Terraced Tower adds a new dimension to Rotterdam’s already impressive skyline. The 110-metre-high residential tower will accommodate 340 apartments for both renters and buyers. The high quality of living is a defining feature of these homes. Full-length balconies and large glazed areas provide breathtaking views as well as a seamless transition between the inside and outside. WICONA contributes project-specific applications that combine light and design with optimal performance in terms of sound, wind resistance and watertightness.
WICONA was brought in at a very early stage of the project by partner and façade builder Byldis Facades, to help devise a suitable solution for the curtain walls and the window and sliding systems. “Together, we visited the contractor Besix NL and other companies to demonstrate how we could customise this project,” says Raimond Stassen, project manager at WICONA. “The Terraced Tower is located not only on the Nieuwe Maas waterfront but also on De Boompjes – one of Rotterdam's busiest streets. For this reason, stringent noise requirements were imposed. In addition, architect OZ Architects and developers Provast and First Sponsor had a number of aesthetic requirements.”
Slim appearance, uniform finish
All apartments had to be fitted with sliding doors with the most slimline appearance possible, Stassen explains. “We fulfil this requirement with an extremely slim intermediate/central stile of only 34 mm, as well as a profile face width of only 66 mm. To create a harmonious aesthetic, we developed project-specific profiles so that the sliding doors and window systems had a consistent, unified look in terms of design, depth and colour finish, while also meeting the highest performance standards. Thanks to an integrated aluminium frame, even the largest windows are perfectly resistant to strong gusts of wind, which can occur from time to time in the harsh winter months.”
Constantly in motion
Another challenge with the sliding doors was the underside, which has to be very streamlined and stable. “Movement can be highly detrimental to proper and reliable operation,” explains Stassen. “Because the Terraced Tower is so tall, however, it’s impossible to prevent movement completely. It’s not unusual for the building to move a few centimetres, particularly in strong winds. To absorb these movements, we worked with Besix NL to develop a special detail, which is installed in the structural frame below the sliding door, keeping it free from vibrations. The same idea has been applied to the other window frames in the apartments, ensuring that the mitred corners are also protected against movement and – as a result – breakage.”
Window doors with concealed fittings
Another project-specific element is the window doors: WICONA’s inward- and outward-swinging window systems can also be used as doors. “For the Terraced Tower, outward-swinging window doors were chosen, along with concealed fittings developed specifically for this project,” continues Stassen. “It was a successful combination.” Last but not least, a number of custom refinements were made to the connection profiles, to the complete satisfaction of all parties involved.
Self-supporting curtain walls with a height of 6.60 metres
In addition to the apartments, the Terraced Tower features a commercial ground floor with restaurants and shops. WICONA was also invited to develop project-specific solutions for this space. As an example, Stassen mentions the curtain walls on the Hertekade side. “OZ Architects insisted that no horizontal steel beams should be visible. This was an unusual request, as we were dealing with a height of 6.60 metres. Whereas we normally recommend adding a support point every 3 to 4 metres on a beam or column, here we achieved a 6.60-metre self-supporting façade!"
A slim appearance was also required for the curtain walls, with a profile depth on the inside of only 200 mm. WICONA responded to this with a special project profile, which differs markedly from the WICTEC 50 standard series – not so much in terms of appearance, but in its internal engineering. “The only way to achieve the necessary static values was to refine the internal structure.”
The first Hydro CIRCAL project in the Netherlands
Finally, the durability of the profiles was important, stresses Stassen. “The Terraced Tower is the first project in the Netherlands to use Hydro CIRCAL!” Hydro CIRCAL is one of the most sustainable aluminium alloys in the world, containing 75% recycled end-of-life aluminium (post-consumer scrap). With emissions of around 2.3 kg of CO₂ per kilo of aluminium, the material has one of the lowest carbon footprint in the world. It’s with good reason that the material has since been used in numerous follow-up projects.”
