Towering Virtuoso in Sweden

In the Sara Culture Centre, named after the Swedish writer Sara Lidman, all of the columns, beams, decks, and walls of the cultural center were prefabricated in a local factory and assembled on site. This method reduces the emissions and gray energy generated from transporting materials over longer distances, reduces construction time and cost, and creates work for local companies.

An insulated envelope

The hotel tower has a double-layer glazed façade through which the wooden structure remains visible. Between the inner layer of high-performance triple glazing and the outer layer of glazing is an adjustable sunscreen made of glue-laminated timber (GLT) louvers. The double-skin glazing encloses an insulating air space that envelops the entire high-rise. This enhances the thermal efficiency of the entire building – an advantage not to be underestimated, since Skellefteå is located close to the Arctic Circle and has correspondingly cold winters.

To maximize overall energy efficiency a hybrid ventilation system was installed to provide controlled ventilation to the large foyers and theater stages. This significantly reduces the loads on the main HVAC system. The architects also implemented a smart grid equipped with an AI unit that, over time, learns to autonomously predict and control the building’s energy consumption according to projected use and occupancy.

The Sara Cultural Center is to become a meeting place for the people of Skellefteå, whether they are interested in culture, want to borrow a book, or just want to talk to each other in a warm, cozy environment.

Read the full interview:

“Informative architecture – Towering Virtuoso in Sweden” in Sixth Holcim Awards

All structural parts are glue-laminated timber, prefabricated in a local factory and assembled on site; hotel rooms consist of prefabricated 3D modules in cross-laminated timber; floors of hybrid timber and concrete (HBV-system) redistribute load from the high-rise and enhance structural stability. Wooden façades alternate with generous transparent portions of the building envelope that allow for passive solar gains and abundant access to daylight inside the rehearsal rooms and other spaces. The building aims to be carbon neutral over its lifespan thanks to the low embodied energy of the structure, the integration of solar panels, and the use of a highly energy-efficient double skin façade integrated with a mobile sun shading system.

Jury appraisal

The Holcim Awards jury Europe was particularly fascinated by the innovative timber construction techniques deployed to achieve this beautiful and sustainable architectural project, which showcases the potential when working exclusively with timber. Making the material choice a question of both engineering and spatial quality was considered a powerful claim. The fact that all the building structural elements are entirely made of wood, including the structural core and elevator shaft, makes this tower quite unique in its genre. The jury applauded the refined expression of the building, the elegance of the massing and the showcasing of the timber structure through a delicate curtain wall.

Key benefits of using timber in Sara Culture Centre are:

• Reduced emissions from material production and transports as compared to a traditional steel and concrete solution.

• Carbon storage during the life cycle of the building.

• The structure is visible from within the building (not covered in gypsum) ensuring a high-quality indoor climate and giving warmth to the spaces.

Pursuing 100% prefabrication through modular construction (Innovation and transferability – Progress)

• Timber construction allows for a high rate of prefabrication.

• The columns, beams, slabs, and walls of the culture center are prefabricated in a local factory and quickly assembled on site.

• Hotel rooms are prefabricated as 3D-modules complete with bathrooms, installations, and finishes.

• Factory prefabrication in a controlled indoor environment allows for higher accuracy and better working conditions.

• Prefabricated elements are transported on site in a "just-intime"- manner and assembled, minimizing noise and disturbance.

• Construction time on site is reduced, minimizing the impact on neighbors, commerce and passers-by.

• Reduced construction time results in lower costs, compensating for the high level of innovation.

A showcase for holistic sustainability (Contextual and aesthetic impact – Place)

Sara is composed of timber volumes of varying scale and transparency combined to give a human scale at street level with lower volumes towards narrow streets, staggering up to the landmark hotel facing the main square. Public areas are accessible from the attractive pedestrian areas, and backstage workshops are also made visible to celebrate the craft behind the creative process, thus vitalizing all surrounding streets.

Facades at street level feature natural wood that will age over time, the timber structure of the high-rise is visible through a double-skin facade. The sustainability concept aims to highlight timber as a sustainable material. Hybrid ventilation, mobile sunshades and high efficiency envelopes allow for great transparency, showing the timber structure from close and afar.