In designing Swedens first timber multi-storey car park, AIX Architects has redefined this most prosaic of building types.
The four-storey municipal building in Skellefteå, in northern Sweden, comprising 141 parking spaces and 700m2 of office and retail space, eschews cold, industrial concrete for the warm tones of glulam and cross-laminated timber.
Built by contractor Setra Plusshus, it is the first multi-storey car park in Sweden made from wood and is part of a residential project in the Ekorren district, which also features a five-storey apartment block, built using Setras Trälyftet timber prefabricated build system.
Magnus Silfverhielm, architect at AIX, said a non-timber underground car park was originally envisaged.
But we thought, as this was a timber residential project why cant we build a timber construction for the car park as well? There are examples of this in Austria, Switzerland and northern Italy where they build with massive wood sections and glulam. Normally these are up to two storeys, but we thought why cant we go up to four storeys?
Part of the inspiration, he added, were some of Skellefteås, older industrial and work buildings, including paper and pulp mills and stables, where large timber sections are also used.
The local authority was interested in the multi-storey concept, as the increased number of spaces would also meet parking demand from shoppers.
Two additional underground floors were designed in concrete, although Silfverhielm said they were not required.
Fire resistance and strength were obviously important requirements for the wood structure. A wood-concrete composite board on the ceiling of the four storeys provides 60-minute fire resistance, while the thickness of the glulam pillars and beams is designed to maintain structural strength if a fire does break out.
The beams are typically 300x300mm and the frame was manufactured by Martinson in Bygdsiljum. All components were prefabricated, simplifying construction, which took about six months.
The floor decks are 127mm cross-laminated timber. It can support the same number of cars as a concrete deck but is one-third of the weight, added Silfverhielm.
Deck surfaces are finished with an epoxy coating because of the potential negative effects of wet tyres on the wood, and for security.
The car park has a ribbed, wooden façade design feature, which also lets in light. The effect, combined with powerful extended eaves, gives Skellefteås central business street a new and exciting appearance. When you get out of your car its a nice atmosphere and you feel a great comfort, said Silfverheim, who is also a professor at Växjö Universitys engineering and design department.
He describes the car park as a new type of building and challenges the practice of dropping urban buildings in a suburban residential context.
He is already talking to authorities in Malmö about doing a similar project and is also targeting potential clients in Gothenburg and Stockholm.
I think it will happen. Its good to have a built example and Im very happy we designed it and it has been executed in full scale. I think it belongs to the future.
Massive glulam beams support cross-laminated timber decks