Concrete construction at The Ox in Amsterdam Nieuw-West

'A true partner in shell construction'

Accurate preparation, a solution-oriented attitude and clean walls. These are just some of the themes that Nick Dijkhof, work planner at Van Wijnen, could appreciate about his cooperation with De Kock Betonbouw during the shell construction phase of The Ox. "The concrete builder not only promised to be a partner in this work, but really was." Together with Martin de Kock, work planner and calculator at De Kock Betonbouw, he looks back on the project.

Dijkhof: "The Ox is an apartment complex in Amsterdam New West with 168 residential units spread over nine floors and with a parking garage underneath. We are building this for Vesteda Investment Management." 

De Kock: "From De Kock Betonbouw, we realized the complete structural work for this. From the foundation to the roof and from advice to realization." 

Dijkhof: "We have quite a bit of knowledge at Van Wijnen, but basically we are generalists. Together with you, as specialists in structural work, we were able to go further into depth." 

Says De Kock, "We looked together for the best approach for the work and chose a combination of wide slab floors, in-situ concrete and precast components. In doing so, we used our own steel wall formwork for both the pouring of the interior walls and those in the basement." 

Dijkhof: "That worked out very well. Normally the plasterer still has a lot of points, but we had virtually none here. The poured concrete walls were of very high quality."

Scaffoldless construction

Dijkhof: "At the front, you also thought along with us about the planning. We had initially asked to always work in a cycle of ten days per floor, but you indicated right away that this was not feasible." 

De Kock: "True. We like to keep a schedule as realistic as possible, to prevent speed from coming at the expense of quality, safety and ultimately the budget; it's always cheaper to do the job right the first time." 

Dijkhof: "We therefore went for fourteen days per floor, and you met that schedule almost every time. At the end, you only needed one extra week to catch up on some work. That's really negligible on a project like this."  

De Kock: "Especially when you consider that we had to pour a total of 5,300 anchors, to hang the HSB facade closure and balconies from later. That had to be done very precisely." 

Dijkhof: "In doing so, you really did precision work: we only had to adjust 2 or 3."

De Kock: "What was also special about our approach is that we built completely scaffold-free. We used our own wide plate support to apply edge tables on the open aisles and end wall scaffolding on the end wall. With a C-hook of about 5 meters arm length, we could always
one floor higher. This saved us a lot of labor hours AND allowed the facade system to be assembled right behind us."

Partner in work

Dijkhof: "A number of unforeseen problems also occurred during the project. That's part of the deal, but the difference is in how you deal with them. You always thought along in terms of solutions and possibilities. The roof floor was not completely level, but you straightened it out. And because of the corona crisis and the war in Ukraine, the whole industry had to deal with significant price increases."

De Kock: "Where beforehand we had counted on 100 euros per cubic meter of concrete, so to speak, it suddenly became 140 euros per cubic meter. But I thought that was a piece of entrepreneurial risk that lay with us." 

Dijkhof: "At first you collected an enormous amount there. Only when things got out of hand did we look together at what we could do. How you handled that was very much appreciated by us." 

De Kock: "That is also what we stand for at De Kock Betonbouw. We want to be a partner in the work and take responsibility. So with us, you don't get an invoice for every little bit of extra work." 

Dijkhof: "Many subcontractors sell themselves this way, but don't keep their promises. You really did act that way: always looking for a solution and doing it together. That is quite unique."