Turku Market Square Pavilions

The Turku Market Square Pavilions were designed with the specific goal of improving the cityscape by creating more intimate, people-friendly spaces in Turku’s market square and simultaneously connecting the underground parking facility to the urban locale above it.

Nestled on the edges of the market square, the pavilion buildings split the square’s vast open space into smaller subsections. There are a total of three pavilions on the market square, the largest along Eerikinkatu street and two smaller ones by Kauppiaskatu and Aurakatu streets.

Read the article in English here.

The pavilions appear to grow from the ground like trees, connecting the subterranean parking garage to the market above. Stairs, shafts, kitchens, and building technology are all concealed inside the windowless “tree trunks”. The roof structures blend seamlessly into the wooden trunks, creating people-friendly meeting spots both indoors and outdoors that have the feel of being sheltered by a forest canopy. The market pavilions combine stairwells, building technology, and a variety of restaurant and business spaces into each structure.

Wood is used as a material not only as a nod to real-life trees but to bring warmth and cosiness to the restaurants, business premises, and sheltered outdoor areas. This provides a warm contrast to the stone and brick that otherwise dominate the market’s material palette. The façades and ceilings are clad with uniform glulam beams, which provide pleasant acoustics indoors. Meticulously designed eaves extend outwards to protect the wooden façade from rain, and welcoming wooden benches integrated into the façade provide passers-by with a comfortable spot to take a break and people-watch. Using wood as a building material also reduces the building’s overall carbon footprint.

Technical solutions

Structurally, the pavilions merge into the concrete structure of the Toriparkki underground parking facility. Hidden inside the pavilions, stairwells ascend from the garage to the market level above. The pavilions have a hybrid structure of steel, concrete, and wood that, together with the building technology, is concealed behind glulam façades and interior cladding. This leaves the building’s most striking element intact, namely its wooden façade.

The roof has an underlying steel structure covered by CNC-milled wood and a felt roof that is painted light grey. The façades under the roof are made of glulam beams and glass, with the beams creating the pavilions’ unique shape. The wooden façade continues in the interior to provide a smooth transition from the outdoors. More than 2,000 glulam beams in total were used to construct the market pavilions.

For the structural designer, the extent of the eave overhangs and the large, glazed areas with no stiffening elements presented the most significant challenges. Elevator shafts of reinforced concrete provide the structure’s overall stiffening together with stiffening structures built into the outer walls on top of the deck.

The lengthy overhangs of the eaves posed specific structural challenges, particularly due to cold bridges and bending. At their longest, the overhangs extend 4 metres on both sides at a point where the entire roof’s cross-section is about 13 metres. Their support structures needed to maintain the streamlined, slim appearance desired for the roof and eaves. The support beam dimensions were dictated by the bending of the eaves, and the beam shapes were optimised using parametric design.

Fire safety is based on an automatic extinguishing system with sprinklers protecting the wooden façades and interiors. An automatic fire alarm system is installed on the eaves to alert emergency services in the event of a fire outside.

The construction project

As the project was a split contract, the various parties needed to collaborate to ensure timely wood component deliveries and installation work.

The façade’s wooden structure was fashioned in a six-month long design process that went through eight alternative models, and the chosen solution was made possible thanks to the team’s cross-disciplinary collaboration that brought together a broad range of expertise and knowledge of materials.

The toughest nut to crack turned out to be the façade’s glulam arches, but the laborious nature of their installation was obvious early in the project, and the team was well prepared for the workload. The curved shape of the façade was made possible with 3D modelling and CNC-milled installation templates.

Wood construction can make impressive advances with projects like this where the cooperation between the different professional groups, designers, and the client is healthy and transparent.

In terms of schedule, the project’s planning and product development took place from February to June 2020, and the façade beams were produced from October 2020 to September 2021. The pavilions were completed in the summer of 2022, allowing Turku’s new market to open to the public in September 2022.

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