2021

Comparing wood and concrete in apartment construction

Image © Wellu Hämäläinen

Arola is an innovative housing project set amidst the natural beauty of Hirvensalo, a newly built area surrounded by the sea. The built project is composed of two four-storey apartment buildings: one wooden and one concrete. Apart from the materials, the two buildings are the same both in size and in the number of apartments. This makes it possible to evaluate the effect of different building materials on construction time and on the carbon footprints and handprints stemming from construction and occupancy. It also allows for comparing the life cycle costs and the experience of residents in the two buildings made of different materials.

Location: Hirvensalo, Turku, Finland

Program: Housing

Size: 5300 m²

Status: Built in 2021

Client: Mangrove Oy, TVT Asunnot

Team: Eero Lundén, Anu Tahvanainen, Emma Koivuranta, Hannele Cederström, Tuuli Toivonen, Bertta Röning, Eero Junkkari

Kirsikka, constructed in wood and Kide, in concrete are identical buildings that differ only in their building materials.

The two buildings are situated side by side and share a common yard, communal sauna and storage for outdoor equipment. Carports and additional storage are placed on the west side of the plot. The shared yard brings people together while the sauna and club rooms provide ideal spaces for activities.

As a comparative study, the buildings were designed to be identical except for construction materials. The project sought to create high-quality rental housing without compromising on architectural quality. Despite the differing structural dimensions, through careful design, the room sizes and ceilings were kept the same. As a result, the wooden building, Kirsikka is slightly longer and taller compared with the concrete building, Kide.

The overall architecture is calm and minimal to accentuate the building materials. Image © Wellu Hämäläinen

The overall architecture is calm and minimal to accentuate the building materials. Kirsikka is constructed from large CLT elements and the facade features light painted vertical wooden cladding with decorative grooves that vary from floor to floor. Kide is made of concrete elements and features a grooved, natural-coloured facade. To maintain a similar appearance to Kirsikka, the width of concrete grooves are also varied. The storeys are emphasized on the facade with horizontal galvanized steel seams that visually divide the buildings into harmonious parts.

The stairs zig zag from floor to floor offering different routes through the building, moreover, encouraging occasional encounters with other residents.

There is an emphasis on community within the building. The stairs are distributed within the entire mass, providing an inner street and meeting place for residents. They zig zag from floor to floor offering different routes through the building, moreover, encouraging occasional encounters with other residents.

The material world of the building exteriors has been extended to the interiors.

Each building consists of 41 apartment units. The apartments are compact, at the same time, comfortable and functional. There are various types of rental apartments ranging from 35m2 studios to large family apartments, however, the design focused mainly on 51m2 to 55m2 one-bedroom apartments. All apartments have inset balconies and on the ground floor, terraces. The building materials extend to the interiors: some of the interior walls of the wood building feature exposed CLT surfaces and the concrete building, exposed natural concrete surfaces.

Concept Diagram