a row of building facades in Oslo, Norway

This Oslo Workplace Is Made of 80 Percent Upcycled Building Materials

Local firm Mad Arkitekter refurbishes an office building using demolition waste, changing the conversation around material reuse.

The European Commission estimates that the building industry creates around a third of the world’s waste. That’s an almost unimaginable volume of demolition debris—wood offcuts, old tile and carpet, pieces of steel, windows that didn’t quite fit, concrete rubble, and more. But viewed another way, all of that garbage is also a wealth of raw building materials waiting to take shape. Is it possible to design a building almost entirely from waste?

For Mad Arkitekter, an architecture studio founded in Oslo in 1997, the potential of reusing construction waste has been an obsession that led the firm to redesign its own offices with largely upcycled materials in 2021. When real estate developer Entra approached the firm about overhauling and expanding a 1958 office building nearby, the firm saw an opportunity to take reuse to the next level. 

Mad Arkitekter's exterior of an office building in Oslo, Norway
Kristian Augusts Gate 13 in Oslo, Norway, boasts nearly 80 percent reused components across a refurbished 1958 office building and an eight-story, 9,200-square-foot addition, cutting the project’s embodied carbon emissions by 70 percent compared with baseline new construction.

This Project Uses Nearly 80 Percent Reused Components

The project, referred to by its address at Kristian Augusts Gate 13, boasts nearly 80 percent reused components employed across the refurbished existing office building and an eight-story, 9,200-square-foot addition. The strategy cut its embodied carbon emissions by 70 percent compared with baseline new construction

At 43,000 square feet in total, the building “is big enough to set an example, but it was small enough to handle,” says Åshild Wangensteen Bjørvik, partner and CEO of Mad Arkitekter’s Oslo office. Her design team sourced materials such as structural steel, tile, bricks, wood, cladding panels, windows, and even concrete floor plates from 25 demolition sites and building projects around Norway that she calls “donor buildings.” Along the way, they proved that reuse has potential far beyond demonstration projects and off-grid homes. 

an aerial view of the exterior of an office building designed by Mad Arkitekter that features a green roof and mismatched cladding panels
The new addition is clad partly in reused Steni panels, partly with metal plates and Cembrit plates (some as old as 35 years) that were sourced from three buildings and cut to size. They’re fastened with a simple screw system, which Åshild Wangensteen Bjørvik, partner and CEO of Mad Arkitekter’s Oslo office, says will make them easy to repair or replace. Brand-new windows were sourced from a residential development that had inadvertently ordered the wrong product. The design had to be adapted, resulting in the staggered layout.

Hurdles For Material Reuse

The hurdles were many: Reuse is not exactly covered by building codes and regulations, the marketplace for reused materials is not well established, and coordinating the construction schedule with the demolition schedules of dozens of other projects required patience and flexibility. Certain elements couldn’t be reused: Glass office partitions couldn’t be found in time, and only three of the addition’s floor slabs could be made of salvage.

Still, 80 percent is remarkable, and Bjørvik is optimistic that Kristian Augusts Gate 13 will create a pathway for subsequent reuse projects. “It was more expensive for these [steel and concrete] components in particular because they are complicated to reuse. But after this project, many others have followed. We made a new pathway, a new routine, a new way of doing things so that it’s much easier now and the cost is going down.”

By Mad Arkitekter, an interior staircase with built in seating, a living wall is in the background
A central staircase was a lesson in flexibility. It was designed to be made from cut-up glue-laminated wood slabs sourced from a demolished school, but delays to the demolition schedule forced Mad to pivot and instead use wooden handrails from a demolished swimming pool; these were stripped of varnish, cut to size, and glued together to form the stairs.

Key Partners for Mad Arkitekter’s Reuse Project

To ensure safe repurposing of structural elements, the Mad Arkitekter team developed partnerships with research institutes and engineers in Norway to test steel and concrete for structural soundness. Support from the City of Oslo was also key. “The municipality really had confidence in us and that we would make a project that could handle both the law and the reuse, and certified that this building would last for years,” says Bjørvik.

The building’s tenant, coworking franchise Spaces, was another key partner. Originally, the interiors had to conform to the Spaces design manual, but given the varied availability of reused materials this wasn’t always feasible. In most cases, Bjørvik says her team was able to find reused materials that fit the Spaces palette, but they persuaded the brand to allow for some flexibility. In the end, Spaces was so invested in the process, it worked with Mad to create a new design manual specifically for reused buildings. 

a brick wall reinforced with steel beams, created by Mad Arkitekter
Three of the addition’s floors were built with slabs recovered from the Regjeringskvartalet government offices that were damaged in a 2011 terrorist attack. The floors were cut into narrow strips, tested for structural soundness, and installed on a reused steel frame. Bricks were sourced from six buildings around Oslo; their construction style, Bjørvik says, is a traditional method commonly seen in old houses around Northern Europe, where brick walls are reinforced with wooden beams. Here the team used steel to meet modern fire safety standards and construction stability standards.

Inside the Space at Kristian Augusts Gate 13

Inside, the space is eclectic and welcoming, decorated with a mosaic salvaged from the 1958 office interior, as well as a bar and central staircase both made of upcycled timber. Office spaces are partitioned by demountable wood and glass walls, and a kitchen on the first floor and terraces on the addition serve as social spaces. A green roof further cements its sustainability credentials. Judged by its popularity with Oslo’s tech and creative workers, the space is a success. “There are a lot of people who want to work in this building, and there’s a wait list for renting space,” Bjørvik notes with pride. 

Her biggest piece of advice for reuse: You have to know your materials. “Everyone seems to think that the building industry revolution is digital. And yes, it can be. But it’s very much physical,” she says, pointing to a photograph of her team inspecting a pile of salvaged lumber. “You can’t just scan everything; you have to use your hands and you have to have a much deeper collaboration between the craftsmen and the designers. It’s an old-fashioned way to do it, but it has to be renewed in the future of building industry.”

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