SAWA

UHPC balconies combine low weight with strong aesthetics in groundbreaking timber construction

Build Year

2022-2025

Architect

Mei Architects and Planners

Engineer

Pieters Bouwtechniek

Builder

ERA Contour, Nice Developers

A GROUNDBREAKING TIMBER BUILDING

SAWA stands as a symbol of the future of construction. A 50-meter-high residential complex in Rotterdam, the Netherlands, built in CLT (Cross-Laminated Timber) and developed with ambitious goals to promote CO₂ reduction, circularity, biodiversity, and social inclusion. The project demonstrates how timber can not only carry large building structures but also help create healthier and greener urban environments. Its visionary concept and strong focus on sustainability earned SAWA the title of “The Healthiest Building in the Netherlands” along with multiple architecture awards.

The building combines the warmth and aesthetics of wood with technological innovation. A central design feature is the balconies and terraces, which not only extend private outdoor spaces but also integrate vegetation, contributing to a vibrant city center. Hi-Con provided the innovative solution that made the large balconies possible. Our Ultra High Performance Concrete (UHPC) balconies were developed to meet extraordinary demands for slenderness, low weight, and aesthetic harmony with the building’s facade.

"The choice for Hi-Con for the galleries and balconies in SAWA fits perfectly with SAWA’s ambitious sustainability goals of minimizing the use of raw materials. This design choice uses 50% less concrete than conventional solutions."

Robert Platje,

Associate Partner, Mei Architects and Planners

UHPC FROM HI-CON AS THE SOLUTION

The use of a CLT main structure placed strict requirements on the weight and anchoring of the balconies – traditional concrete was simply too heavy. The solution was UHPC balconies from Hi-Con: slender, yet extremely strong and durable. The material enabled a weight reduction of around 50% compared to a regular concrete solution, making it possible to realize slim balconies without compromising the project’s sustainability ambitions. In addition, UHPC is naturally fire-resistant without the need for extra fire protection. A clear advantage for both safety and long-term building performance.

In total, Hi-Con delivered 238 tailor-made UHPC balconies for SAWA, including a spectacular connecting walkway. The balconies feature a wood structure and color tone on the front that beautifully complement the warmth and natural appearance of the timber facade.

©Ossip

HOW UHPC COMPLEMENTS TIMBER CONSTRUCTION

The combination of high strength and low weight makes it possible to create light balconies that enable striking designs without overloading the timber structure’s load-bearing capacity. Surfaces can also be customized with textures and colors.
UHPC is naturally fire-resistant and requires no additional fire protection. A property that can provide significant cost savings in fire safety.
The material withstands weather and wear for over a century without structural maintenance. That means longer service life and a strong LCA profile – ideal for CLT projects.

©Ossip

INNOVATIVE COLLABORATION THROUGH EARLY INVOLVEMENT

Early involvement and close, ongoing dialogue between Mei Architects and Planners, Pieters Bouwtechniek, Era Contour, and Hi-Con laid the foundation for the innovative balcony design. Through creative, multidisciplinary collaboration, the team developed a UHPC solution that not only met the technical requirements for weight reduction and anchoring but also added a striking visual element to the building.

The result is more than just a balcony solution. It is an example of how advanced concrete can be integrated into modern timber architecture to create buildings where ambition, aesthetics, and functionality come together.

Curious about how our slim UHPC elements can take your project to the next level? Get in touch with us. Our specialists are ready to provide advice and collaborate with you.