Last year, Triodos Bank welcomed its newest office, a green-roofed circular building that raises the bar for sustainable architecture. Designed by Amsterdam-based firm RAU Architects in collaboration with Dutch interior design firm Ex Interiors, the new Triodos Bank office in Zeist was envisioned as a wooden “cathedral” to nature with lofty, light-filled interiors that feature exposed wood, organic forms and full-height glazing throughout. Certified BREEAM Outstanding, the energy-efficient office also doubles as a “temporary materials bank” where the construction materials can be disassembled, transported and reassembled elsewhere without loss of value.

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Located in a forested landscape on De Reehorst Estate, Triodos Bank’s new office was deliberately designed with no clear front or back. Instead, the five-story office consists of three rounded towers wrapped in full-height glazing that are alternately connected on the ground, first and second floors via skylit spiral staircases. The organic composition takes inspiration from nature and the flight paths of bats, according to the architects.

Related: Fully circular office can be sustainably demounted and rebuilt in weeks

walkway around curving glass office building
stone reception area in office building

Aside from the basement that was built of concrete due to the water table, the building is constructed almost entirely from wood with 1,615 square meters of laminated wood, over 1,000 square meters of cross-laminated timber and five original tree trunks. The CLT cores and the laminated timber rafters that wrap around them are left exposed to emphasize tall, cathedral-like ceiling heights and to inject a sense of warmth throughout the building. Most of the timber used for the furnishings and floors were directly sourced from the estate.

wood tables and chairs near glass walls
round wood tables near large planter filled with greenery

“A building as an option for the future — RAU Architects sees a circular building as a temporary combination of products, components and materials with a documented identity,” architects explained. The building is fastened together with over 165,000 screws for easy dismantling. “The origin and planned re-use of all products, components and materials are carefully documented in order to be able to easily offer them new usage in the future.”

+ RAU Architects

Photography by Ossip van Duivenbode via RAU Architects

aerial view of green roofs on rounded building