Pihlmann Architects takes reuse to a new level, shredding, compressing, repositioning and reinstalling 95% of building elements to turn an old Copenhagen warehouse into an arts centre
Adaptive reuse usually means changing a building’s function. At Thorajev 29 in Copenhagen, Pihlmann Architects has taken this a step further. Not only has the project repurposed an unremarkable 1960s warehouse as an arts space, it has reimagined the building elements themselves, turning walls into paving, beams into tables and whole slabs into staircases.
Pihlmann calculates that 95% of the existing materials were reused, reducing embodied carbon by 88% and construction waste by 90% compared to new construction.
The most eye-catching interventions are the three wide processional staircases, which have been cut out from the slab and tilted downwards to connect the four floors together. This was, in many ways, the key to the whole project, particularly as the client had specifically asked for a number of double and triple-height spaces.
The former fur warehouse was a long, horizontal four-storey building, with low ceilings and poor natural lighting – hardly a promising space for galleries and artists’ studios. Behind the street-facing facade of brick panels and bands of glazing, it had a precast concrete structure of columns and 1.2m-wide TT beams, joined together into floorplates. By cutting out six beams to create a huge 7m x 7.2m opening in the floor and then lowering one end like a drawbridge, Pihlmann has unlocked a variety of larger spaces and vertical connections.
The team tracked down the concrete manufacturer’s original drawings of the precast elements from 1966. “This gave us very clear and accurate information relating to the pretensioned rebar inside the TT beams,” says Isabella Priddle, an architect at Pihlmann. From this data, the engineers designed a steel brace that could be inserted at each end of the 1.2m-wide beams. This allowed the tension in the rebar to be preserved after the floorplate was cut.
To remove the floor sections, a core was drilled through each end of the TT beams. Hoists were then attached, and a small crane lowered them to the ground floor. This was used as a storage zone for all materials while the building was being stripped back to its frame.
Before reinstallation could take place, bespoke steel brackets were bolted to the slab edge using the existing connection details for the TT profiles. The ceiling height varies from floor to floor, changing the gradient of the stairs, which meant that the brackets had to be designed to different angles on each level.
On the ground floor, the slab rests on a steel footing, leaving a gap between the first step and floor level. “We found another piece of concrete that had been extracted from elsewhere in the building, and that turned out to be the perfect height for the bottom stair,” says Priddle. “It was an example of something that we hadn’t designed originally – we just had to be creative and make the most of what we had to hand.”
The architects had originally envisaged a raw metal aesthetic for the steel connections, but it needed to be painted to achieve the required fire rating. “That was a bit of a challenge for us. But there were a lot of metal elements in the building, such as radiators and lamps, that had aged over time to become this off-white yellowish colour – we called it smokers’ lounge yellow. In the end we decided to use the same colour for all of the new metalwork. We’ve also reused as many radiators as possible, so you'll see a lot of radiators in the final building that are the exact same colour. It was quite a fun use of colour, something that alludes to the building's past and adds a lot of warmth to it.”
The stair treads, which are supported by brackets fixed to the TT beams, have a bent profile with seams that align with the joints between the concrete elements. “There are a lot of details that you notice in person but you can't quite communicate with an image,” says Priddle. “Where the guardrail intersects a column, for example, it sweeps behind it in quite a playful way. We’ve used a lot of these fun little gestures to draw attention to certain things.”
The aesthetic of inventive reuse and raw finishes continues throughout the building. The slab above the entrance has been cut out to create a double-height atrium, with the distinctive TT-profiled concrete repurposed as furniture, including a bar counter in the ground-level café. As you move up the building, smaller spaces such as studios and workshops are introduced, divided by untreated plasterboard and exposed door frames.
Plain mineral‑wool board fills the gaps in the TT decks for acoustics. Waste wood from the original building has been shredded and re-formed as MDF-type panels. Metal has been compressed into blocks, used as table legs, magazine holders and other furniture.
On the south-facing elevation, a 1.5m-deep thermally glazed extension has been added, creating more circulation space and a means of vertically connecting the services without making further incisions in the concrete frame. The north, street-facing elevation also has new, efficient glazing with raw aluminium framing at ground-floor level, giving the building a more welcoming public face. The bricks removed from the facade have been cleaned and reinstated as paving in front of the building.
Søren Pihlmann, the architect’s founder, describes this type of reuse as driven by the materials. “Some elements remain exactly as before, while others have been resurfaced, shredded, compressed, repositioned or reinstalled. The transformation is guided by the inherent physical properties of each component, rather than its conventional or aesthetic value.”
Since opening in 2024, the building has already become home to about 30 organisations, mostly from the cultural sector. A piece of building-integrated artwork by one of the tenants has added to the playful spirit, connecting the stairs and soffits with a pulley system of yellow ropes and tempting red handles. “It plays on the idea of being able to pull the slab back up into place, but it doesn't actually move anything,” says Priddle. “It really feels like a piece of the building though – everybody tries to pull on those red handles …”