Oulu Central Library ‘Saari’ is located in the heart of Oulu, on Vänmanninsaari Island along the Oulu River. Completed in 1981, the library was designed by architects Marjatta and Martti Jaatinen. Adjacent to the library stands the Oulu City Theatre, also designed by the Jaatisens and completed in 1972.

The buildings form part of a nationally significant built cultural environment (RKY) and represent a restrained modernist approach to concrete rationalism. The ensemble is based on a general planning competition for Oulu’s administrative and cultural centre held in the 1960s.

JKMM Architects was responsible for the project’s head design, architectural design, as well as the interior and loose furniture design. The client was Oulu Tilapalvelut, with users including the Oulu City Library, the children’s cultural centre Kotilo, and the City of Oulu’s community services. The guiding principle of the design was to respect the building’s modernist concrete architecture and preserve its original spirit, while updating the spaces, building services and accessibility to better meet contemporary needs.

Architecturally, the building is a clear rectangular volume with façades combining mosaic concrete, aluminium and glass. The double-height library hall on the second floor opens towards the market square through a large window, while the ground floor is recessed. The 6 × 6 metre structural grid allows for flexible spatial organisation within the building. The interior spaces emphasise openness, transparency and carefully selected materials. From a conservation perspective, the most significant spaces include the entrance hall, the sculptural concrete main staircase, and the double-height library hall on the second floor. Glass walls surrounding the main staircase create visual connections between floors and activities.

In the renovated library, the fourth floor has been opened to public use for the first time, with a new stair connection added from the upper landing of the main staircase. A new lift has been installed, and the existing lifts have been renewed for public use. Accessibility has been improved throughout the building, and additional restroom facilities have been added to each floor. The most extensive and challenging part of the renovation was the complete renewal of building services: new technical spaces were added, routes reorganised and system principles redefined — within very limited space and with extensive technical requirements.

The renewed ground floor now functions as a vibrant level for events and encounters, housing a café as well as the interconnected event spaces Pakkala Hall and Laituri. The second floor forms the heart of the library: an open, light-filled library hall with extensive collections for users of all ages. The third floor offers spaces for quieter activities, including group work rooms, reading rooms and a digital workshop. The fourth floor, now open to the public, brings together the children’s cultural centre Kotilo, bookable meeting rooms, small sound-insulated studios, and staff workspaces.

JKMM Architects also designed the interior architecture, following the principles of the original architecture and the furniture design by Studio Nurmesniemi. The original material palette combines expressive in-situ cast concrete surfaces, mosaic concrete, aluminium and glass, softened by warm ash wood finishes and colourful furniture. Varied sightlines, spatial sequences and natural light remain central to the spatial experience. From the second-floor library hall, views open towards the Torinranta area and the new plant-based artwork Sininen saari (Blue Island) by Urho Kähkönen, which brings seasonal change and vitality to the building’s surroundings.

The renovated library reopened to the public in November 2025.