Located in the centre of Helsinki, the Kaivokäytävä passageway presented a challenging renovation site because the pedestrian traffic along it could not be stopped during the work. Almost 20,000 people use the route daily. All changes to the frame were carried out with in-situ cast steel and concrete structures. Kaivotalo’s car ramp leading from the ground level to the basement was replaced with a new intermediate floor that forms a passageway running behind the Kaivokäytävä covered passage’s shops. Business premises were built on the second floor, which is served by a new escalator leading up from Kaivokäytävä. All the surface structures, including the glass walls, were replaced. The glass ceiling and surrounding ceiling structures were replaced, apart from the steel frame. New floor structures offered additional floor space for the second-floor shops.