Turku city hall renovation costs surge by €26 million due to worse-than-expected building conditions

The renovation of Turku’s city hall and six surrounding buildings will require an additional €26 million after inspections revealed far more extensive rot, hazardous materials, and structural deterioration than initially estimated, public broadcaster Yle reports.

City officials will present the revised budget to the municipal executive board on Monday, with final approval resting with the city council. Tuomas Heikkinen, Turku’s chancellor, acknowledged the request would face resistance. “The council won’t exactly welcome this with open arms,” he said.

Further surveys and demolition work uncovered higher concentrations of creosote, a toxic wood preservative, as well as more decayed timber frames than projected. “No one could have predicted the cost overrun would be this severe,” Heikkinen added. The full extent of repairs for the historic structures will only become clear as work progresses.

Foundation reinforcement alone has demanded significantly more labor before walls and interiors could be dismantled. To meet modern standards, the project must now address moisture control in the foundations, airtightness in the exterior envelope, and upgrades to ventilation systems. The scope of the renovation has also expanded beyond original plans.

Initially budgeted at €30.4–34.5 million (including preliminary courtyard costs), the total price tag now exceeds €60 million. As an alternative, the executive board will consider a phased approach, though this would likely force some buildings out of use permanently. Kimmo Suonpää, Turku’s director of urban development, dismissed staggered repairs as impractical. “Delaying the work isn’t a real solution. These buildings are still salvageable in a way that preserves their cultural value—if we act now,” he stated.

Construction began this year with piling work along the Aura River. Despite the cost increases, Suonpää confirmed the timeline remains unchanged, with completion slated for Turku’s 800th anniversary celebrations.