Pakila Halkosuontie wooden school

The Pakila district in northern Helsinki now has a new wooden school building for its 3rd to 9th graders. Completed in April 2022, this school on Halkosuontie street is one of the first modern woodenframed schools that the City of Helsinki has built.

Read the article in Finnish here.

To meet the City of Helsinki’s carbon neutrality goal, the new school building has solid wood structures. To gain insight into the project’s potential for carbon neutrality, the City conducted a carbon footprint comparison at the beginning of the project. As a result, the decision-makers invested in a wooden frame despite its higher cost. To keep the carbon footprint small, it was important that all new construction and any repairs to the site’s existing building were kept as low-carbon as possible. Carbon neutrality was considered to be as important as functionality, safety, the well-being of people in the building, and costs in the project.

The new wooden school is an expansion of a cherished older building already at the site. Designed by Jorma Järvi in 1953, the original building is being repaired as part of the project. A gangway connects the new wooden school to its brick predecessor. Out of respect for this brick architecture, the wooden school’s building mass has been designed to fit in with the older building and brick has been used for the façade. The project is an excellent example of how a solid wood frame can still be the best choice despite a historically demanding environment – and that a wooden frame does not necessitate a wooden façade.

In the interiors, the visual contrast of the new and old parts of the building is quite noticeable. Repairs to the old school building respect the architectural choices of the 1950s, whereas in the wooden school, the load-bearing wooden structures have been left on full display. CLT surfaces are visible all over the school, especially around the canteen in the centre of the building, in the main staircase, and on the exterior walls of the learning spaces. Wooden fibreboard with beautiful groove detailing lines the ceilings of the main spaces to improve acoustics.

Technical solutions

The new wooden school is built with a CLT frame that combines two wooden structural systems, namely a load-bearing wall system and a pillar-beam system. The vertical structures are CLT panel and glulam, while CLT slabs with load-bearing delta beams serve as the horizontal structures. The roof is built from wooden roof elements made with LVL and OSB products, among others.

CLT walls and mast pillars brace the building and handle the loads transferred from the horizontal structures. For added support, the HVAC building technology room has a CLT-concrete composite slab floor.

The construction project

The extensive construction project for the schools and daycare centre in the Pakilanpuisto area is being handled by an alliance formed by the City of Helsinki, architectural firms Arkkitehdit Rudanko + Kankkunen and AFKS Arkkitehdit, contractor NCC Suomi Oy, design firm Ideastructura Oy, and engineering firm FCG Suunnittelu ja Tekniikka.

The large-scale project includes all the new school, daycare, and youth premises in the Länsi-Pakila district. The on-going second stage involves a new building for daycare and 1st and 2nd grade students, which will be completed in 2023 on a nearby plot. A special feature of both schools are the new building’s learning spaces specifically designed for students with severe disabilities.

The construction project’s alliance model is based on the close cooperation of its key parties. Together, the client, the designers, and the contractor are jointly responsible for the project’s design and implementation. As this project spanned several plots, the alliance pondered the various possible placements of all the functions in cooperation with the appropriate city division. Residents of the area were also presented the various options and given an opportunity to make their voice heard in resident workshops and online surveys.

CREDITS

Arkkitehdit Rudanko + Kankkunen and Arkkitehdit Frondelius + Keppo + Salmenperä (AFKS) have collaborated on demanding school building designs since 2015. Their alliance was born when the two architectural firms decided to team up for the Sipoonlahti school design competition. Both firms were interested in scaling their know-how of educational facilities to larger sites and to learn from a partner at the same time. Their mutual design philosophy emphasises functionality and a desire to retain the values of the existing environment. Their teamwork is democratic and deliberative, with the two firms in constant dialogue about their designs. Individual parts or tasks on a site are handled separately by each team, but the bigger picture is always drawn together. This conversational approach has made them more open-minded in their design language and added a level of storytelling and clarity to their shared projects. Their architecture is refined through joint deliberation.