SILT Middelkerke
The SILT project, the absolute eye-catcher on the Belgian coast, is an architectural masterpiece located between the dike and the dunes of Middelkerke. This versatile building, designed by architectural firm ZJA, in collaboration with OZ, Bureau Bouwtechniek, and DELVA landscape architects, provides direct access to the beach, a truly unique experience. Reynaers Aluminium offered high-performance solutions and on-site support to help complete the impressive award-winning building envelope.
Contemporary design with historical influences
The multifunctional building houses a casino, a restaurant with terrace, a foyer, an events hall with a capacity of 1,700 people, a hotel with about 60 rooms and underground parking. From the casino floor, visitors enjoy a breathtaking view of the sea.
The design of the casino building reflects the experience of the historic coastal landscape in a contemporary way, extending the nearby square with an artificial dune. The event hall, restaurant and casino are hidden under the dune, but offer spectacular views thanks to the transparent façades and spacious terraces. Atop the dune is a park-like square where events can take place.
Architectural challenges
The striking building envelope presented several technical challenges, particularly due to the unique wooden outer shell with an X-structure draped around the hotel. The wooden structure of the façade is suspended from the shell and is interwoven with the aluminium façade for added stability.
Stable aluminium façades
The aluminium curtain wall is composed of a steel support structure that is essential to keep the façade stable in windy and salty circumstances. The steel cables running through the aluminium profiles provide additional strength and seamlessly connect the different elements of the façade.
Anticipating thermal movement
The transition between the glass façade and the adjacent glass roof required thorough cooperation between the various building partners. Sufficient space between the various components of the curtain wall and the glass roof is necessary to account for thermal movements, caused by the hot sun or freezing wind. As a result, special attention was given to the water tightness and expansion possibilities of both façade parts at the expansion joints in the underlying shell structure.
To evaluate the performance of the waterproofing between the façade and roof components, a water test was performed on site. Additionally, all glass roof elements were provided with a double sealing barrier and smooth drainage of rainwater to limit dirt accumulating.
ConceptWall 50: unlimited design freedom, excellent performance
For the aluminium façade and glass roof, fabricator Allaert Aluminium chose Reynaers Aluminium's ConceptWall 50 curtain wall system. This versatile stick façade offers unlimited design freedom and strong energy performance, making it an excellent choice for projects with high sustainability requirements. With ConceptWall 50, it is possible to achieve the desired transparency and incidence of light without sacrificing strength or energy efficiency, as was proven in this challenging project.
ConceptWall 50 is highly compatible with our other aluminium solutions and can easily integrate elegant opening elements. For SILT, MasterLine 8 windows and doors, as well as the MasterPatio sliding system were added to create one continuous façade.
Facing coastal challenges through pre-anodisation
Building on the coast also means considering several natural factors. Water, sand, salt, and wind can cause corrosion and affect the durability of the structure. To ensure the longevity of the materials and maintain the aesthetic quality of the building elements, a pre-anodisation treatment was chosen for this project.
Pre-anodisation is a pre-treatment process applied to aluminium profiles before they are powder coated. First, the surface is cleaned and impurities are removed, providing a durable base to prevent corrosion. Next, a very thin layer of the aluminium is oxidised in a controlled manner. This oxide layer enables even better protection against external influences. After pre-anodisation, SILTs windows and sliding doors were powder coated in RAL colour 9005, a deep black hue that provides an elegant contrast to the anodised curtain wall profiles.
With anodisation, this process is slightly different. Here, a thicker oxide layer is applied to create a seaside AA pre-treatment, which increases resistance to corrosion. All curtain walls of this landmark are anodised in a light golden-bronze colour (C31), which matches the building's modern and sustainable design, and seamlessly blends with the wooden outer shell.
Water testing, a necessary step when building in coastal areas.
Project support from design to implementation
Given the mixed-use nature of SILT and the high number of visitors, ensuring acoustic comfort was quite a challenge. Reynaers Aluminium carried out detailed acoustic studies during the design phase to minimise noise pollution and ensure a quiet environment for hotel and restaurant guests. These acoustic studies resulted in specific recommendations for the Ug value (heat transfer coefficient) of the glass, which had to meet the sound insulation requirements.
During the implementation phase, we provided further technical support to our partner Allaert Aluminium. This included regular site visits to check construction progress, provide feedback and ensure that work was proceeding according to our specifications. Part of these site visits was checking the complex connection between the sloping façade and the adjacent skylight in the entrance hall. On-site water tests helped to verify the effectiveness of the seals and to ensure that no leaks would occur in the future.
An iconic beacon for Middelkerke
Innovative and durable design at such a remarkable location does not go unnoticed. At the Architecture Masterprize 2024, held at the Guggenheim Museum in Bilbao, SILT was one of the winners in the “hospitality architecture” category. However, it was not the first award SILT had won since its grand opening in March 2024. Already during its construction phase in 2022, the multifunctional venue received the prestigious International Architecture Award, granted by the Chicago Athenaeum and The European Centre for Architecture Art Design and Urban Studies (ECAADUS).
The SILT project marks a new milestone in architecture and urban development on the Belgian coast. With its innovative design, sustainable materials and multifunctional spaces, SILT offers not only a spectacular landmark, but also a unique experience for visitors. Reynaers Aluminium's extensive project supervision and technical expertise contributed to the successful realisation of this iconic building, which forms a harmonious link between the city and the beach. SILT is an example of how modern architecture and respect for the historic coastal landscape can go hand in hand.
