Kasia House: A library with floating balconies

Turning a former department store into Finland's largest academic library

University of Helsinki Kaisa House Library Design | Case Studies

The oval atrium of Kaisa House, concentric balconies floating above a busy ground floor. The curved balcony walls finished in Rockfon Mono Acoustic, controlling reverberation.

Designing Finland’s largest academic library

When the University of Helsinki decided to build a new central library in the heart of the city, the ambition was practical: bring together the collections and study spaces of several faculties, arts, education, law, theology and social sciences, under one roof.

Designed by Anttinen Oiva Architects on the site of a former department store, Kaisa House opened in 2012 and immediately captured the public imagination. Affectionately nicknamed "Lady Kaisa" by Helsinkians, it won the annual award of the Finnish critics' association within months of opening.

At the centre of it all is a design decision that makes the building what it is.

Shaping a spectacular atrium

The heart of Kaisa House is a soaring oval atrium that rises through the full height of the building. White balconies on every floor float like concentric rings, drawing the eye upward.

It is a genuinely spectacular space. It is also, by its very nature, an acoustic challenge.

A tall, open atrium with hard surfaces, stone floors and thousands of students moving through it daily generates significant reverberation. For a library, where concentration and quiet are the whole point, that's a fundamental problem.

The architects needed a surface material that could follow the complex curves of the atrium precisely, delivering a smooth, continuous finish, while also absorbing sound at the level an academic library demands.

A standard ceiling solution wasn't going to work here.

Project info

Project name

Kaisa Library at Helsinki University

Client

University of Helsinki

Location

Helsinki, Finland

Architecture

Anttinen Oiva Arkkitehdit

Installation

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Products used

Rockfon® Mono Acoustic

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A curved, seamless, Class A surface

To achieve the smooth and curved surface of the atrium balconies, Anttinen Oiva Architects specified Rockfon Mono Acoustic. Its seamless surface follows complex curves without interruption, allowing the balcony walls to feel as one flowing form.

The smooth white surface reflects and diffuses natural light, while the stone wool core delivers Class A sound absorption, the highest level available, managing reverberation across the full height of the atrium.

Throughout the rest of the library, where curved surfaces weren't required, Rockfon® Industrial™ Opal ceiling tiles were installed behind stretch-metal mesh, a perforated metallic layer that maintains the industrial character of the space while allowing sound to pass through to the absorbing surface above.

The result is a building where the acoustic strategy is as carefully considered as the architecture itself. Students can concentrate. Researchers can work. And the atrium can be the visual centrepiece as intended.

Kaisa House is a former department store converted into a library.

Rockfon Mono Acoustic ceilings achieve Class A acoustic control in the atrium.

The curved, seamless Rockfon Mono Acoustic surface running along the first floor meeting rooms.

Looking straight up to the glazed roof, the Rockfon Mono Acoustic surfaces drawing light down through the atrium.

Lady Kaisa: An Helsinki landmark

Lady Kaisa has become more than a library. It is a demonstration of what happens when architectural ambition and acoustic design are treated as part of the same plan from the start.

Also working on a space where complex curves and acoustic performance need to work as one? Get in touch, and together we'll find a solution that follows your vision without compromise.