Floor slabs tilted into staircases, facade elements reworked into paving, fittings transformed into furniture: the transformation of Thoravej 29 in Copenhagen by Pihlmann Architects allows a former factory building to recycle itself. The project reflects a pragmatic approach to available resources, reassessing the value of the existing fabric by treating the building as its own material bank.

An industrial building reworked for arts and social life

Originally designed in 1967 by Danish architect Erik Stengade, Thoravej 29 was first used by Danske Pelsauktioner, later Kopenhagen Fur, before being converted into laboratories for the Geological Survey of Denmark and Greenland. It subsequently served as Copenhagen’s municipal office of disability services.

In 2021, Bikubenfonden acquired the building. That same year, Pihlmann Architects’ proposal for its transformation won first prize in an invited competition organised by the foundation. The subsequent renovation has created a centre for visual and performing arts, as well as social projects. Today, Thoravej 29 houses stages, galleries, exhibition spaces, studios, workshops, offices, meeting rooms, a production kitchen, canteen, and cafe. It accommodates a community of 150 people across 30 organisations working in artistic development and social work.

Dismantling and reuse

The new programme required fundamental changes to the building’s anatomy. During the renovation, the building was stripped back to its core: a column-and-beam structure with precast concrete TT slabs, also known as double-tee slabs, and facades defined by horizontal window bands.

Lightweight walls and built-in furnishings were removed, while other elements were relocated. Everything dismantled in the process was stored with the intention of being reused in the completed project. Even components typically considered insignificant were treated as potential resources.

An external analysis shows that the transformation achieved a reuse or recycling rate of 95 percent by weight of existing materials. The largest climate benefits came from preserving the load-bearing parts of the structure, which are usually among the most resource-intensive elements to produce. Compared with new construction, this contributed to a reduction in carbon emissions of up to 88 percent and a 90 percent decrease in construction waste. The reductions were supported by the careful dismantling, storage, and reintegration of structural elements, surfaces, and interior components, preventing most demolition waste from being sent to landfill.

Material logic

The logic of reuse shaped both the building’s material expression and its spatial configuration. The degree of processing varies: some elements remain as they were, while others have been resurfaced, shredded, compressed, repositioned, or reinstalled. The transformation is guided by the physical properties of each component rather than by its conventional use or aesthetic status.

Material remnants are encountered throughout the building in ways that are both direct and discreet. The building’s history is treated as part of a cyclical system, with elements preserved through reuse and given new roles within the transformed spaces. The resulting architecture is shaped by subtraction and adaptation rather than addition.

Reworking the structure

The building’s horizontal organisation has been reconfigured by converting load-bearing TT slabs into broad staircases and integrated furniture. This intervention connects the floors, creates spatial variation, and shifts the thresholds between levels. The existing slabs provided a modular kit of parts that was structurally sound, well maintained, and of high quality. Their reuse helped determine the visual and spatial transformation of the building. By finding ways to rework existing materials, the project was able to use lower-carbon solutions that also contributed to the character and legibility of the space.

The listed facade facing Thoravej, once closed off, has also been opened. The upper levels have been preserved, maintaining the area’s remaining industrial character, while the ground floor is now more closely connected to its surroundings. Large windows and transparent garage doors establish a direct relationship with the public realm, while bricks removed during the transformation have been reused in the paving, extending the building’s material fabric into the surrounding urban space.

Lifetime extension

The life expectancy of a comparable office building from the 1960s is around 70 years, meaning Thoravej 29 may otherwise have been approaching the end of its expected service life. Through the transformation and adaptation of the building to current needs, the longevity of Thoravej 29 has been extended. For Pihlmann Architects, lifetime extension is one of the most overlooked environmentally beneficial strategies.