Building cheaper and faster with precast facade elements

Prefab celebrates heyday in High Five

VIANEN, Sorba Projects and Facédo were involved in the development of High Five at a very early stage. "In close cooperation with contractor VORM 2050, architectural firm OZ and shell builder Stabiel Management, we fine-tuned the design for the hsb façade elements," says Oene Wassenaar, director of VIANEN. "For example, to increase the manufacturability, affordability and safety. We worked out the complete design in 3D/BIM and clashed extensively. Moreover, in collaboration with all the manufacturing parties, a realistic and efficient lean planning was tuned."

Excellent air and water tightness

A major challenge involved the air and water tightness of the element connections, says Wassenaar. "Together with Sorba Projects and Facédo and before the start of this project, we built a full-scale mock-up of two floors with four façade elements, which allowed us to test all detailed connections in real time. From the longitudinal seals to the transverse seals and intersections. In the process, the facade elements were tested through to a test pressure of 600 Pa, whereas 300 Pa was the requirement." By including air and water sealing already in the prefabricated construction process, an even higher construction speed can be achieved, he emphasizes. "Moreover, contractors can even better meet requirements such as BENG, Zero-in-the-Meter, BREEAM and the Quality Assurance Act. After all, the sealing products are applied under the best labor and climate conditions."

Fireproof and soundproofing

Following air and water tightness, specific requirements applied to both fire resistance and sound, Wassenaar says. "For example, fire propagation and sound transmission through the facade must be prevented. Various measures were taken for this, so the precast facade excels in all areas."

Modular base

At the base of the precast façade elements are VIANEN's modular hsb elements. "Characteristic of these elements are the fixed height and width dimensions, which are exactly matched to the frames, windows and glass fronts that come in them," says Wassenaar. "The inside of the elements is fitted with gypsum fiberboard, which has excellent fire and sound insulation and can be finished immediately. On the outside will be a fiber cement board, which will be finished completely watertight. The same applies to the sides of the hsb elements." On the side are packing surfaces, on which two foam bands will be placed. "Where the front band takes care of the waterproofing, the rear band takes care of the air sealing. With this we are in line with the VIANEN Guarantee framework, which guarantees perfect air and water sealing."

Scaffold-free® assembly

The hsb elements are fitted with gold-colored aluminum composite cladding and plastic window frames at VIANEN's factory in Montfoort, says Wassenaar. "From here, the prefabricated facade elements are transported to the construction site ready-made, just-in-time and exactly according to the assembly sequence, where assembly company Kuijpers Uitvoering & Advies BV, commissioned by VORM 2050, assembles the elements scaffold-free®. Here, a rate of up to ten elements per day is achieved!" By assembling scaffold-free®, VORM 2050 can build much faster and cheaper. After all, no scaffolding needs to be placed around the residential towers. "In addition, the building is wind and watertight in one go, allowing the interior finishing work to begin immediately." Just before the 2025 construction period, the last elements will be delivered.