A@W Newsletter

The coast presents one of the most challenging environments for facades. Wind, salt, and sand relentlessly batter buildings, making meticulous care of the exterior essential rather than optional. The recently completed event building in Middelkerke, finished in March of this year, exemplifies efficient and creative solutions to these challenges. Aptly named Silt, this striking structure is situated directly on the beach and features a distinctive oval hotel tower, making it a new landmark on the Belgian coast.

The unusual design is the work of Amsterdam-based architectural firm ZJA and DELVA landscape architects, in collaboration with OZ and Bureau Bouwtechniek and a range of experts, who together formed Bouwteam Nautilus. They argue that this building commissioned by client municipality Middelkerke has various functions in terms of coastal reinforcement, livability and sustainability, and that it aims to return a piece of the vanished historic coastal landscape to Middelkerke in a contemporary way. The central feature is the hotel tower, which is complemented by a casino, a restaurant, a multifunctional event space and an underground parking garage. Optimal energy supply, waste treatment and production processes were sought in the complex. Due to its oval shape, the building has a complex geometry, which was designed parametrically by ZJA.

Silt is literally planted on the beach, making it a new focal point on the coast.

To talk specifically about the approach to the facade, we spoke with the project architect responsible at ZJA, Leo ten Wolde. Ten Wolde was involved in this project as early as the tender phase, and followed up until completion. Even now you still see him every now and then in Middelkerke, if, for example, a tour is to be given.

Thinking about materials

The architect first outlines how, during the design phase and in consultation with the municipality of Middelkerke, careful consideration was given to the materials used for the facade. These materials needed to be especially robust to withstand the demanding climatic conditions. The final choice was ceramic materials, Accoya wood, and anodized aluminum.

On the Belgian coast, with its almost constant west wind, you have to meet very specific requirements.

Leo ten Wolde: "In Belgium you hardly find any requirements more specific than a location on the coast, especially with the almost constant westerly wind. The first thing we had to think about was the approach to the shaping, particularly large canopy. What would be the best material for this? Inland, you could possibly opt for aluminum cassettes, but we soon had to dismiss that possibility. We also thought for a while about working with fiber-reinforced concrete, but eventually found that this became too complicated because of the shape. In the end, the choice fell on ceramic material because we know that it holds up well in difficult conditions. On the coast it already proved its worth countless times in apartment construction, among other things."

Sustainable Accoya wood was used for the façade.

"We were determined to incorporate wood into the facade, despite the challenges of doing so in that location. Ultimately, we chose Accoya, an acetylated softwood preserved through a non-toxic chemical process using acetic anhydride. This process gives the wood characteristics similar to (tropical) hardwoods. Accoya also ages beautifully and requires very little maintenance over the years. Additionally, the building features a lot of glass and anodized aluminum, which proved to be the best choice. Aluminum snap frames and plates were used for the glass frames."

Oval shape tower building

We have already highlighted the building's unique shape. Silt stands out with its overhead oval design in an area dominated by neatly aligned, ten-story apartment buildings. The decision to use this oval shape was influenced by several factors.

Leo ten Wolde: "While the oval hotel tower is iconic, it represents only about 10 percent of the entire project. Most of the structure is underground, with just one ground floor. Our concept aimed to avoid making the building too large, which would obstruct the square and the connection to the sea. Therefore, we extended the building underground as much as possible, including levels -1 and 0, along with an additional parking layer. The nice thing is that people simply walk over most of the building."

The building has a lot of glass. For this, anodized aluminum proved to be the best choice.

"For the hotel tower, we chose an oval shape for a number of reasons. For example, conversations with a wind expert revealed that a westerly wind usually blows on the Belgian coast. Large, angular towers are not recommended in such a case because they deflect the wind and possibly cause squalls on the square in front of the complex. There was also a practical aspect: in the case of the protruding section, a bit more rounded is also simply better for the view of the surrounding residents on the coastline. They simply look more past the building. In terms of aesthetics, we wanted to break with the very austere image that characterizes most of the Belgian coast. Especially since it was an event building, we were happy to revert to a more natural form that allows the municipality and the environment to make a more powerful statement."

Technical data sheet

Building Team Nautilus is a Dutch-Belgian collaboration between:

Architect: Principal designers ZJA (architect) and DELVA (landscape architect) in collaboration with OZ (casino and hotel design) and Bureau Bouwtechniek (executive architect)

Developer: Debuild

Consultants: COBE, VK Engineering, Beersnielsen, Witteveen+Bos, Plantec, MINT and Sertius

Contractors: TM Furnibo-Democo

Opening: March 2024

All Pictures: © Stefan Steenkiste und Sebastian van Damme

Originally written by Jan Hoffman