CKK Jordanki, a multifunctional culture and congress centre in Torun, Poland, is located within a green ring around the historic city centre, overlooking the Vistula River. Its main values are:
(1) respectful integration with the town's material and cultural heritage and (2) high adaptability both to different distributions and to a wide range of acoustic needs; (3) picado, a creative recycling of reclaimed bricks for a new material with good acoustic effects.
(1) The building occupies half of the plot, the other half being given to public park and the height is kept as low as possible in order to keep unblocked the view over Vistula. Its materiality refers Torun's Gothic legacy, an UNESCO protected city, in which the façades of the old town boast of red brick. CKK Jordan's interior is covered with picado, a mix of concrete and crushed red bricks and some of this lining comes out on the façade.
(2) The concerts hall is able to adapt easily to different capacities and acoustic needs; you may join two rooms to act as the main theatre and you may open it to the outside. Thanks to its dynamic ceiling, the building can be tuned to effectively absorb a wide range of performances.
(3) Picado is a mix of concrete and other materials. At CKK Jordanki, it was mixed either with reclaimed red bricks from a local factory (Ceramsus) for the sound reflection effect; or with a volcanic reddish stone from China, for its sound absorption effect.
CKK Jordanki is a collective place because of its program, it is a congress and culture centre, so one could say it is collective by nature. But it is also collective by design. Each of the mobile parts of the ceiling can move independently from 3 to 5 m in height, allowing adjustment of the geometry and volume of the hall, depending on the needs of each moment, transforming a volume of 8200 m3 with a time reverberation of 1.85 seconds, into a volume of 6,800 m3, with a reverberation time reduced down to 1.35 seconds. By adding additional absorption you could reach a reverberation time of 1.2 seconds, which covers the entire range of possible activities: 1.85 seconds for symphonic music, 1.6 seconds for opera and 1.2 seconds for theater. The plastic properties of the concrete were complemented here with the surface treatment - picado - a crushed brick and concrete mix, allowing a kind of diffusion, very difficult to achieve with other materials.