Sibelius Hall is a main venue within Congress and Concert Centre that was designed as the permanent home of the Lahti Symphony Orchestra. The Centre opened in spring 2000.

Artec assisted the City of Lahti with an international architectural competition, working with three finalists to develop separate architectural schemes. Artec then developed the design with the competition winner. Sibelius Hall is a purpose-built concert hall with 1250 seats, which are distributed on the main floor and on two balconies, as well as behind the platform as seating for a chorus.

The Hall incorporates features that allow for great acoustic variability, including a moving canopy, acoustic control curtains, and banners. The three-piece adjustable acoustic canopy facilitates on-stage communication among the musicians and can adjust the response of the "performance end" of the room, to suit individual musical works. Acoustic control curtains can be extended to absorb some of the reverberant energy, creating a "dry" sound environment. Sibelius Hall also incorporates reverberance chambers, which assist in adjusting the room's acoustics to match a particular repertory or ensemble. Hinged doors can be set to varying degrees, allowing differing amounts of sound to pass in and out of the chambers.

Artec provided Design and Planning services covering Pre-Design Phase services, Auditorium Design, Facility Planning, Specialized Performance Equipment Systems Design and Noise & Vibration Control consulting. The architect for Congress and Concert Centre was Arkkitehtityöhuone Artto Palo Rossi Tikka Oy.