Faster construction through optimal prefabrication
The existing homes in Utrecht's Linschotensingel could in no way meet contemporary standards. The lack of insulation and the presence of thermal bridges meant that there was really only one option: demolish and start over.
Housing corporation Portaal awarded Bouwbedrijf Van Dillen the phased contract for the plan/redevelopment of Plangebied Oudegeinlaan. It is currently building the 96 homes on the Linschotensingel with a Design&Build contract. It was up to her to develop the best plan for this. In response, Bouwbedrijf Van Dillen chose a plan with a high degree of circularity. The old concrete will be used to pave the ground floor and the wood from the old joists will be used for the production of new window frames.
To keep construction time as short as possible, the project is being prepared in 3D. "This makes the plan fully comprehensible before the first spade goes into the ground," says Rik Schippers, work planner at Bouwbedrijf Van Dillen. "Subsequently, many building materials were prefabricated. These include gallery slabs, balconies and parapets with cast-on stone strips, as well as the HSB elements manufactured by our own Culemborg precast plant containing wooden window frames manufactured by our own Culemborg Timmerfabriek."
A monthly newsletter will keep the surrounding area informed. This allows everyone to know what to expect and on which days inconvenience can be expected. "In addition, a resident supervisor is active, who forms the link between construction and the neighborhood. This works very well for both us and the local residents. There are fewer questions. Residents who still have questions can just walk in to the construction worker."
To ensure smooth execution, work is done in two construction streams. Schippers: "Due to the short construction time, it is always swarming with people on the construction site. Yet all these people must have sufficient working space. We arranged this by working in two construction streams, each starting on the first floor. Once the installer has finished his work, for example, he moves to the floor above and the flooring specialist takes over his place. In this way, all parties always have the entire floor at their disposal."
Because Housing Corporation Portaal wants to make the housing available to a broad target group, the housing units vary greatly in size. They range from one- to five-bedroom apartments. Nevertheless, Bouwbedrijf Van Dillen has to realize them within one building system. "To achieve this, we erected the main shell in cold cast concrete," Schippers explains. "In this, in addition to the reinforcement and pouring facilities for the prefabricated elements, the systems are also cast in. Thanks to the metal stud walls, the houses become freely divisible."
Thanks to meticulous preparation, the new construction of the 96 apartments on Linschotensingel - from the first pile to completion - will take only 11 months. At the end of the year, the homes will be handed over to the client.
The concrete shells for the houses on the Linschotensingel and Vronesteinlaan are being built by Casco Bouw Nederland. Because of the high construction speed, a deployment of four shifts was chosen, with overlapping schedules in each case. Phase 1 includes the foundations with the ground floor floors, phase 2 the tunnel cycle on the Linschotensingel including the prefabricated galleries, phase 3 all HSB facades and the prefabricated balconies and phase 4 the shells on the Vronesteinlaan in sand-lime brick and the wide slab floors.
"We were involved in the project at an early stage by Van Dillen," says Jan Hokse, general manager of Casco Bouw Nederland. "We went through things together and actively collaborated on the most appropriate construction system for this project. Given the amount of repetition, we ended up with tunneling for the Linschotensingel. It is the construction method with the highest construction speed. Unfortunately, due to the limited space, the blocks on Vronestein Avenue could not be tunneled."
The joint preparation makes for pleasant mutual cooperation. Although implementation has only just begun, Hokse already dares to speak of a well-run project. "That joint preparation from the first moment pays off handsomely during execution."