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Case study: thermal architecture in Finnish language school

Large windows and open, spacious rooms characterize the new language school in Jakobstad, Finland. Construction began in March 2019 and in August 2020 students and teachers moved in.

Thermal architecture

Individual learning needs

The school can accommodate around 400 students from preschool to fifth grade. When creating the new language school flexibility was key to ensure everyone’s needs can be met. “The expectations of today's and tomorrow's students require a new kind of education. The structure remains the same, but we now have flexible space solutions that allow for flexible teaching, so we can respond even better to the students’ individual learning needs," says Kristiina Hellstrand, head of the language school.

The open learning environment inspired lead architect Hilkka Maija Antila of NAC Arkkitehdit Oy to create an environment that stimulates curiosity and gives students and teachers the opportunity to be creative, inventive and enthusiastic. “In all planning, it is important that the environment you create stimulates the users. The environment should never consume energy.”

The language school has both smaller and larger classrooms without walls. Sound-absorbing curtains, seating areas, chairs and tables separate the rooms. 

Radiators prevent cold spots at large windows

The school’s interior features airy spaces and a natural colour scheme that creates calm and harmony. Delta radiators blend into this natural environment in terms of both colour and design.

"We chose large windows to give space to the learning environment. However, it’s also important to consider the cold draft that occurs around these windows," says SAFA architect Hilkka Maija Antila. “That is where radiators play an important role in combating cold that occurs near the large window areas.”  

“The radiator under the window prevents cold drafts from the windows. The cold air currents moving along the window are slowed down by convection in the radiator or convector. On top of that, the radiation coming from the front of the radiator is important for the comfort in the rooms, as it compensates for the cold surface of the window, commonly called cold radiation. Thanks to these two phenomena, the radiator makes the room more functional, since the usable space can be used much closer to the window without compromising on comfort. These phenomena and their consideration already in the design phase of the building are called thermal architecture," says Mikko Iivonen, Product Development Purmo Group.  

Interiören kännetecknas av luftiga utrymmen och en naturnära färgskala som skapar lugn och harmoni.

The school is designed with natural colors and wooden surfaces. 

Inredningen går i naturnära färger. Purmos Delta radiatorer följer samma färgskala. Kulör: RAL 9002.

The interior design is in natural colors. Purmo's Delta radiators follow the same colour scheme. Color: RAL 9002. To improve acoustics, many floors are carpeted, and the lamps are also sound-absorbent.

Delta radiators integrated into sills at large windows

One particular challenge was to integrate the radiators in front of the large window sections.

Students tend to sit on radiators when possible. That's why we decided to integrate some of the radiators into functional benches," says Hilkka Maija Antila. “The HVAC design was done by Sweco (formerly Avecon) and the installation work by Larsmo Rör.

“The initiative for an open learning environment came from city representatives and is the first of its kind that we have implemented. A very inspiring and rewarding project to have been involved in,” says Hilkka Maija Antila.

Munkformade pallar finns utplacerade här och där och en del radiatorer har integrerats till funktionella bänkar.

Monk-shaped stools stand here and there, and some radiators have been integrated into functional benches. 


Jakobstad is a multilingual city where people work together for a functioning multilingualism. The language bath was established in Jakobstad in 1992 using the so-called early full language bath method, and a separate language bath school - Kielikylpykoulu - was opened in 2003 with classes from preschool to sixth grade. The language bath is a voluntary teaching method in which language is acquired through use in natural situations.

Språkbadsskolan har en modern fasad i rost.

The language school has a modern facade.

Facts about the Språkbadsskolan language school

Client: City of Jakobstad
Architect: NAC Arkkitehdit Oy
HVAC design: Sweco (formerly Avecon)
Contractor: Peab
Building automation: Caverion
Ventilation: Bravida
Electrical installation: Sähköpalvelu Walberg
Pipe laying: Larsmo pipes
Radiator solution: Delta sectional radiators from Purmo

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