Floating Office in Rotterdam Rises Above Threats of Climate Change

While we may not experience a devastating impact from rising sea levels in our lifetimes, there is no doubt it’s happening incrementally. The average global sea level is predicted to rise by at least two to three meters (6.5 feet to 9.8 feet) over the next 2,000 years, according to February 2023 data from The World Meteorological Organization.

But certain countries will be endangered well before that, claims the United Nations. The Netherlands is one of the four nations most at risk, so Dutch architects and developers are already thinking ahead.

In Rotterdam’s Rijnhaven harbor, architecture firm Powerhouse designed an office that can literally ride the wave of sea-level change by floating.

The 4,500-square-meter building, which is now home to Powerhouse’s offices and the Global Center on Adaptation (GCA), hovers on concrete blocks in the port and employs robust eco-friendly features. With renewable energy, modular construction and environmentally conscious building materials, the BREEAM Outstanding-certified and energy-positive Floating Office Rotterdam (FOR) is a showcase in sustainable building practices.

Constructing a building that could successfully float was a feat in of itself.

The building rests on 15 six-meter-by-six-meter concrete pontoons anchored together to create the floating foundation, and the structure is laid out in a repeating grid system that makes it symmetrical and balanced.

“Otherwise, you're going to be tilting to one side or the other,” said Albert Takashi Richters, partner at Powerhouse, noting that the tides in Rotterdam cause the office’s elevation to change by an average of 1.5 meters throughout the day.

“Sometimes we have high differences of over two meters,” he told LoopNet. “We are constantly moving, which is of course an interesting effect when you're in the office because the relationship with the water is always changing ever so slightly, which is nice actually.”

Since anything more than a barely perceptible shift in height wouldn’t be pleasant during the workday, the designers had to be precise in ensuring the building was as symmetrical as possible for optimal balance.

“You can compensate with ballasts and such, but you don’t really want to do that because it will increase material costs, effort, and will add more weight to the structure — it’ll make everything a dimension bigger which will end up requiring more material as well,” said Richters.

The symmetrical grid also benefited the modular construction process, in which all building components were built off site, towed through the port and then assembled on site, hence the long, horizontal shape of the building to keep its width small enough to pass through the drawbridge.

Unlike the modular approach usually employed for multifamily buildings, where individual units are stacked on top of each other, the purpose of the modular technique in this case was to drive sustainable construction and make the building part of the “circular economy.” The building is demountable, and all materials and components are meant to be easily reused where possible.

“We made the columns, the beams, the windows, and all of these elements as repetitive as possible,” said Richters. “The modular system allows us to basically unscrew the building by its different components. So, you could use the beams and the columns as they are in a new building or structure.”

The construction also used sustainably sourced laminated timber from Germany that can be much more easily reused than concrete or steel, which requires significant heat to melt down for reuse. “The lifecycle of wood is much longer [than steel]. Even after its regular lifespan, it can be milled down into sawdust that can then be used for composite materials, for instance,” said Richters.

Energy positive and carbon negative, the building powers itself only through renewable energy sources. The southern half of the pitched roof is covered with 870 square meters of solar photovoltaic panels, generating around 154 megawatts per hour of electricity every year — 109% of the energy required to run the office. The extra power goes back to the city’s grid. “So, we are a source of energy for the neighborhood,” said Richters.

The other half of the roof is a green garden ecosystem, and the gabled roof is not only an aesthetic choice, but a functional one as well.

“We can angle the southern roof more efficiently towards the sun, and that makes our solar panels much more efficient,” said Richters. Additionally, the pitched roof overhangs provide natural sun shading for the balconies and office’s floor-to-ceiling glass windows.

With such expansive windows, cooling is one of the main energy concerns for the office. The building uses its surrounding water for cooling, circulating it through a heat-exchange piping system in the concrete foundation and pumping it through ventilators.

“We actually don't need air conditioning, we just have cooling through the water temperature,” explained Richters. “And that, of course, obviously saves us a lot of energy.”

Rising sea level wasn’t the only reason Powerhouse decided to position FOR in the water. Representing the largest harbor in Europe, the Rijnhaven waterfront is undergoing a transformation from a port to a commercial and public space, but is running out of room for development, said Richters.

“There’s an innovation taking place in the former harbor areas of the city, because the city is basically encroaching on old harbor docks and basins,” he said.

Meanwhile, the GCA, an organization commissioned in the Netherlands in 2018 by the United Nations, was looking for a new office location. With the Dutch government’s commitment to combatting climate change and its extensive research on “the rise of sea levels and the technology necessary to protect us,” Rotterdam was a natural choice, said Richters.

While FOR was first and foremost designed for GCA as the client to represent its mission, Powerhouse also located its offices in the building.

The architecture firm takes up half of the ground floor and the second floor, totaling 1,600 square meters. The team wanted a very collaborative space that provided places to display work, meet and have informal conversations, and added movable magnetic walls that can migrate through the office for flexibility.

In addition to the four meeting rooms, quiet booths dispersed throughout the office for individual focused work were one of the most requested features by employees. Two libraries, one for architectural materials and samples, and one that serves as a study, offer more variety of workspaces.

A grand wooden staircase connects the two floors and can serve as an amphitheater for presentations.

FOR also features its own restaurant and bar on the second half of the ground floor, outdoor terraces and balconies, and a pool in the harbor.

On the other hand, GCA has a different approach to its workspace than Powerhouse does. “They require many more rooms because they have a lot of meetings, online calls and seminars, while Powerhouse needs a much more open concept where we hardly have any walls or rooms,” said Richters. “I think it was really good to see those two concepts come together in the building and show that the building allows for that flexibility, and the design allows for those different kinds of uses.”

That flexibility, and the simplicity with which it’s incorporated, along with the seamless sustainability features integrated through the project, make FOR a north star for climate-resilient buildings of the future, said Richters.

“[This project] taught us that efficiency can be done in a very elegant way. It was obvious that sustainability was a key component of the design, but we didn't want to make a building that oozed sustainable technology,” he continued. “We wanted to make it feel completely integrated into the design. We didn't need to add windmills or obvious amounts of green. We managed to come up with a design where it was fully integrated and just kind of speaks for itself.”

That’s how the future of architecture should be, he continued. “We will all have to commit to sustainable and energy-efficient designs, but at the same time, I think elegance and beauty still remain very important. So we will somehow have to integrate that technology within the aesthetics of a building. And this floating office was very much a test case for that.”