Over existing construction and partially on W columns 

324 floating rental units

Keep Amsterdam livable, not for a select few but for diverse groups of people, including those with modest incomes. How to do that. At Koningin Wilhelminaplein in Amsterdam-West, a neighborhood upon a neighborhood is being built. The underlying building is "pierced" with supporting columns, laying the foundation for 324 floating rental units. 

Thus, none of the housing in OKU House is ground-level. One section was built above the former Fashion House, which is currently being redeveloped into OKU Office, with supporting columns running right through the office building. The other section is placed on W columns so that the dwellings appear to float between OKU Office and the
adjacent Berghaus. 

An exciting year

Real estate developer Boelens de Gruyter sold the plan to housing corporation Stadgenoot, Achmea Real Estate and De Ranitz B.V. Dura Vermeer Bouw Midden West is realizing it: 112 social rental housing units for Stadgenoot, 108 medium- and free-sector rental housing units, 104 free-sector apartments and a two-story parking garage for Achmea Real Estate and commercial spaces for De Ranitz B.V. "It has given us an exciting year," confesses Richard van Dijk, company manager at Dura Vermeer Bouw Midden West. "We are realizing a neighborhood on a neighborhood with logistical and structural complexity."

Installation of box floors

The exciting year began with the installation of 12 huge steel columns, right through the office building below. The box floors were mounted on the girders attached to the steel columns. They are constructed of colossal, elongated steel boxes over 16 meters long and weighing 35 tons. "The combination of the supply of equipment and materials and the limited space on the project site made the installation challenging. The heavyweights dangled in the air and had to land in the cantilevers cut out in the concrete for this purpose," Van Dijk says. "It was two incredibly exciting moments."

The basis for the wings

Much of the equipment had already been installed in the steel plant between the box floors. These were covered after landing with a concrete reinforced compression layer 15 cm thick. This was the foundation for the "wings" of the building. This was followed by the concrete skeleton with the provisions that in turn had to connect precisely to the provisions in the prefabricated aluminum element facades from which the facades were later suspended. Van Dijk: "Every action was a dimensional job and tolerances were minimal. Once in a while we adjusted an anchor; there was no more leeway."

200 prefabricated steel balconies

The finishing touch involved the assembly of over 207 prefabricated steel balconies. "The installation of the balconies required precision work. Just think of circumstances such as strong winds. The balconies - complete with fencing - were maneuvered to their destination by crane and suspended from anchors that had been poured into the concrete beforehand." 

Meanwhile, OKU House is in the completion stage. The utilities are being installed, the interior walls installed and the molding floors poured. "Around the 2024 construction period, OKU House will be ready for occupancy. Soon the new residents will be able to enjoy a green walking area under the floating residential towers."