A building that absorbs all stormwater

An important role in the implementation of the green concept behind VERTICAL is played by Van der Tol. With a sophisticated water management system, customized façade and roof greenery and various fauna provisions, the project in Amsterdam Sloterdijk will form an ecological connection in the green zone between Lange Bretten and Westerpark. The high-rise tower was slated for completion in late 2022, the low-rise later this year. "Each roof garden is in fact unique per floor," says client manager Casper Korteweg of the green specialist.

The so-called vertical gardens of the residential building are part of the "Brettencloth. In DS Landscape Architects' sustainability vision, the greenery of the western Bretten zone is pulled into the city over VERTICAL's buildings, making Sloterdijk part of an ecological zone running from Spaarnwoude through Amsterdam's Westerpark to the ring of canals. VERTICAL's façade gardens, green roofs, wall plantings and nesting boxes (encapsulated in a high-rise and low-rise section) encourage flora and fauna in the area, with the aim of increasing biodiversity based on native species. The green concept also significantly reduces heat in the residential area. "The residents will soon be completely surrounded by greenery," Korteweg said.

Water storage

The planting in and on the facades and roofs was chosen based on the seasons and facade directions, with their varying weather effects. Korteweg: "For each floor, this is customization - also in terms of building height and size of the terraces." 'Red thread' in the wall planting, for example, is the wild vine, a climbing plant that turns a beautiful red in autumn. In addition, VERTICAL has an essential water storage function, an ambitious part of the design. All rainwater must be retained on the plot. "In traditional construction, rainwater goes to the sewer system as quickly as possible; in this project, it is absorbed by the building itself. Rainwater is collected in the different layers of the roof garden structure. This design is ideally suited to absorb summer downpours."

Warranty

The challenges of "green" high-rise buildings also have a functional component: the technology that makes the ambitions possible. Van der Tol specializes in the development and implementation of green projects with both hard and soft aspects. "For VERTICAL, for example, we supply a complete water management system, in this case equipped with 150 millimeter thick retention on the upper roof and several buffer layers on the floors below and inside the building. We provide a 10-year waterproofing guarantee on the entire roof and roof garden system, in cooperation with roofing contractor Mastum Daksystemen under the Life on Roofs guarantee scheme." 

VERTICAL is a long-term project with a large engineering and execution component for Van der Tol. Construction began in the spring of 2021 and the high-rise tower was completed and delivered in December. Phase 2 (the final phase) will be delivered before the 2023 construction season.