Image: Copyright PPHP

The city hall building in Zaanstad, the Netherlands, is an iconic landmark reflecting the country’s traditional canal house architecture. Externally, it resembles a series of tall colourful houses, while inside is a modern office complex.

Fitting on a small plot between a railway and busy road – and with a bus station below - the iconic design, restricted location and budget constraints created challenges for Royal HaskoningDHV’s structural design team.

Design method enables reduction in material costs

The structural design team worked very closely with the architect to ensure the project remained within budget. One of the dramatic features of the building is an arched, narrow roof which soars above the council meeting room without support from columns. It needed to be both lightweight and carefully designed to avoid the need for support.

“It was a very sophisticated design,” said Marc Bijvoet, Project Leader. “We made the drawing and structural analysis in a 3D package which enabled us to make best use of materials and reduce building costs. This was long before widespread use of 3D and provided a unique benefit for our client.”

City hall project integrated with larger development scheme using 3D model

The building as a whole sits on columns above the bus station. This too presented a technical challenge. Stocky columns were designed to provide adequate stability and a special foundation was used to transfer the loads effectively into the ground.

The city hall building was the initial stage in a larger development scheme and linked with a bridge into the city and another across the railway. The 3D model was also useful for accurately managing interfaces with future projects.