Architect Joop van Stigt designed Cluster Zuid for the Faculty of Humanities of Leiden University in the late 1970s. The extension was reinaugurated in 2024 as Herta Mohr. Photo courtesy De Zwarte Hond

Studio De Zwarte Hond Reimagines Dutch University with Circular Renovation

The Herta Mohr building showcases how resourceful reuse can transform a legacy structure into a sustainability paradigm.

Established in 1575, the Dutch Leiden University is a public research institution with two campuses, seven faculties, and five science clusters. Ranked 17th on the global UI Green Metric sustainability index, the university aims to achieve carbon neutrality by 2050.

As part of a bold, 12-year vision to transform the Humanities Campus, Leiden University is reshaping over 462,500 square feet with redevelopment, renovations, and new construction. The renovation of the Herta Mohr building renovation, formerly the Cluster Zuid school, represents just one phase of this initiative.

“The biggest challenge was transforming the building while honoring its monumental status,” says Bart van Kampen, partner at De Zwarte Hond, the architecture studio in charge, reflecting on the late 1970s design by structuralist architect Joop van Stigt, under whom van Kampen studied.

Photo courtesy Eva Bloem

Sustainable Construction Leads to Interactive Spaces

As a listed building within a protected campus, Herta Mohr has a facade on which changes were kept minimal, preserving striking features like its prefabricated concrete columns with conical capitals and round balconies, now fully visible in the renovated structure.

De Zwarte Hond reimagined the fragmented layout of seven disconnected “houses” into a unified building around a spacious, light-filled atrium to inspire interaction and knowledge sharing. Previously, dark ceilings, narrow corridors, and small windows with wired glass cast a gloomy atmosphere that made navigation difficult.

Photo courtesy Stijn Poelstra

The second floor of Cluster Zuid underwent a complete transformation, while an “eighth house” with an anodized aluminum facade was added. This fulfilled an element of van Stigt’s original design that was never realized and extended the building by over 32,000 square feet. 

BREEAM Excellent certified, the Herta Mohr building now offers 172,332 square feet of space, including more than 700 teaching spaces, two lecture theaters, libraries, work and meeting rooms, and common areas.

“About half of the building costs went towards new installations, with the other half allocated to structural changes,” says van Kampen, adding that around 70 percent of the original building materials were reused to minimize environmental impact. 

Reclaiming Heritage while Enhancing Energy Efficiency

The concrete columns, made in situ in the late ’70s from the demolished central house, found new life in the extension. “We cut them loose from the floors and moved them to the new extension without any problem. The concrete tested flawlessly, with no rusted steel inside. Its quality is outstanding—I’m confident it’ll last another 150 years,” says van Kampen, highlighting how repurposed materials align with the university’s future-proofing strategy.

The Sequoia redwood ceiling panels were repurposed as wall cladding in the atrium. They were carefully milled in collaboration with BWRI, a social development organization supporting individuals with disabilities and other employment barriers. The slats’ specific pattern allowed for prefabrication and installation, minimizing waste.

“We had around 65,000 square feet of ceiling wood available, but we used only around 43,000 square feet. Some of it is stored on-site, and we’re planning to repurpose it for our next project,” says van Kampen, whose firm is also tasked with revitalizing two buildings adjacent to Herta Mohr building.

Over 430 solar panels, green roofs, and a ground-based thermal storage system drive the building’s energy efficiency, making it the university’s first fully gas-free structure. This system alone will cut carbon emissions by 150,000 kilograms annually.

Photo courtesy Eva Bloem

A Key Focus on Biodiversity and Biophilia

Biodiversity was also a key consideration. The design blends indoor and outdoor spaces with a butterfly garden, bird nesting spots, and insect habitats. The climate-adaptive front square mitigates heat and absorbs rainwater, promoting both social interaction and environmental well-being.

This balanced focus on long-term sustainability mirrors van Kampen’s approach to architecture. Despite the challenges posed by Cluster Zuid’s protected status, he advocates stricter preservation to minimize unnecessary demolitions, emphasizing that buildings should be valued as long-term assets.

Van Kampen concludes, “We should protect more buildings to prevent their demolition too quickly. Buildings aren’t disposable products to be discarded after a few decades.”

Video credit: De Zwarte Hond & Harryvan

Would you like to comment on this article? Send your thoughts to: [email protected]

Latest