From boilerhouse to creative design studio

Troldtekt ceiling panels from 1957 are preserved in an exemplary transformation in the Danish town of Aabenraa.

Troldtekt acoustic ceilings are the natural choice when wanting to ensure superior acoustics and a healthy indoor climate in, for example, office buildings
Photo: Thomas Mølvig, arkitekt

The tall brick chimney towers well above the centre of Aabenraa and marks the location of the ZENI architects’ design studio. The old boilerhouse, Kedelhallen, was constructed as part of the Varmecentral Humlehaven heating plant in 1957 and was in operation until 2012. Now, it has been transformed into a modern workplace with high ceilings and openness at every level. ZENI architects have achieved a very inspiring transformation which is now included among Denmark’s six best refurbishment projects in 2020.

After it ceased operations in 2012, the heating plant was purchased by BoligSyd, which took up residence in the buildings’ former offices. When BoligSyd asked ZENI in 2018 for help in setting up offices in a third of the boilerhouse, the architects immediately saw the potential of the rest of the space.

In dialogue with the developer, BoligSyd, a project was designed that would preserve as much of the industrial atmosphere as possible. At the same time, an extensive refurbishment project was required to create a contemporary setting for ZENI, who themselves wanted to move into the stunning space. In 2018, the huge boilers were hoisted out of the building, and in March 2019 ZENI could officially inaugurate the new design studio.

Original ceiling was preserved

Initially, the intention was to retain as much as possible of the building’s character. The exterior is therefore almost unchanged, apart from large new windows that create excellent contact between outside and inside. In practice, however, it was necessary to rethink the interior as the brick building lacked insulation. Kedelhallen has therefore been insulated on the inner walls and the roof has been insulated on the outside.

On the ceiling, the existing Troldtekt acoustic panels installed in 1957 have been preserved. This was done in light of the architects’ considerations of sustainability and authenticity. Why change something that works in terms of functionality and as an aesthetic element? The coarse white-painted panels work incredibly well with the visible red-painted steel rafters that span the entire space.

In such a voluminous space, acoustics are naturally a crucial parameter. And Troldtekt acoustic panels in the ceiling cannot do it all alone. The walls are therefore clad in perforated plywood sheets with underlying insulation. The simple wood brings warmth to the character of the room. In addition, smaller meeting cubicles and niches have been set up so that employees can retreat a little when needed.

The nomination for the Danish Retrofit Award 2020 was explained as follows:

“The transformation of Kedelhallen proves wonderfully that preserving buildings does not impede the development of a modern and vibrant city, but rather helps to preserve the cities’ DNA and distinctiveness.”