Platform on new construction, renovation, restoration and transformation
Right in the heart of Rotterdam, Coolsingel 93 (C93) is undergoing an impressive transformation. The former bank building is not only being extensively remodeled, it is also being scaled up from approximately 72 to 99 meters in height. The superstructure consists of a steel structure combined with a relatively lightweight ComFlor 46-layer profile steel sheet-concrete floor. And that is quite unique by Dutch standards.
The ComFlor 46 profile is used less often than, say, the higher 95 profile, knows Gernand van Dijk of Stedupro, the company responsible for installing the floorboards. “This is precisely where the advantages come in handy. We are dealing here with relatively small spans. With slab sizes between 170 and 270 centimeters, the floors are easy to handle and safe to process at height.” Coolsingel 93 was realized in phases. “For each storey, the steel structure was first assembled, on which we mounted the ComFlor 46 slabs. Assembly started in May 2025 and took about 35 working days.”
ComFlor 46 is a low-profile steel sheet-concrete floor with a profile height of 46 millimeters. “In this project, we worked with sheets of 1.2 millimeters thick, which made stamp-free installation possible,” Van Dijk reflects. Dutch Engineering, distributor of the steel plate concrete floors, is a regular partner of Stedupro. By the way, this cooperation is reciprocal: they know where to find each other in projects. “Given the complexity of Coolsingel 93, we have placed the entire drawing and engineering process with Dutch Engineering, including the control calculations and the drawing in of the cladding,” says Van Dijk. “We like that cooperation very much, because of the enormous knowledge and experience in-house. Moreover, the choices made are substantiated with neat reports.” Van Dijk further praises the delivery reliability and market-based prices. “In the field of steel plate concrete floors, Dutch Engineering is really a step ahead of the competition.”
The inner-city location of Coolsingel 93 required sophisticated logistics. “In consultation with main contractor De Vries en Verburg, Dutch Engineering delivered the ComFlor panels to a depot nearby. The panels were then transported to the construction site on demand and assembled directly from the truck. That tight organization made a reliable partner indispensable.”
