The ACA flats project in the Dutch town of Utrecht-Overvecht involved the renovation and revitalisation of 362 homes with the design led by architectural firm DOOR architecten for housing corporation Mitros. Equitone also played an important role in the project.

While the entire project comprises a total of 1,800 residential units, the 362 homes of the ACA flats (ACA stands for Apollo, Centaurus and Atlasdreef) made up the first phase. For ACA, DOOR architecten worked with Over Morgen (a provider of sustainability, energy and installation advice), principal contractor Hemubo and KCP, which together with Hemubo was responsible for liaising with the residents.

The DOOR architecten team comprised of architect and structural engineer Terry Pater and Karin Dorrepaal. Pater explained the philosophy behind the project and the choice of EQUITONE facade panels.

"For the ACA flats, we started with a meticulously designed sustainable basis – the chassis, so to speak. That chassis will be the same for all 1,800 residential units in the project. We devoted a lot of time and energy into the engineering of this chassis, and it shows. The result delivers a high RC value, good airtightness and a strong architectural statement. On top of this chassis, of course, comes the bodywork – the cladding. This differs per project and ensures a completely different look for the various sub-projects, while retaining certain similarities,” Pater said.

“The ACA flats will have a robust, stylish looking facade. We have chosen Eternit as the supplier for the facade panels, because with the EQUITONE ranges Linea, Tectiva and Materia, Eternit offers a wide range of options in terms of colour combinations, of smooth and rough surfaces, shading, mutual contrasts, etc. The effect of the sun makes the building look very different at different times, which is a nice aesthetic plus."

The circular approach

In their approach, DOOR architecten often emphasise the circular aspect. "That doesn't mean that we only carry out circular projects," says Pater, "but they do make up the majority of our work. If we receive non-circular assignments, we will always inform the client about the sustainable options that we can offer. It's simply in our DNA. The ACA project received an honourable mention in the Dutch Betonprijs (Concrete Award) in the 'circular' category, on account of the reuse of the existing concrete shell. In other words, the existing concrete did not have to be demolished, removed and then re-produced and rebuilt. We also reduced the ecological footprint, by minimising the cutting and sawing losses on the facade elements."