Kuninkaantammi wooden apartment buildings

In the spring of 2018, A-Kruunu completed the construction of two wooden four-storey apartment buildings in Kuninkaantammi, Helsinki.

Located at Taidemaalarinkatu 6, the site includes two residential apartment buildings, an unheated underground garage and an auxiliary building in the yard. The apartment buildings, which have a total of 58 apartments, are interest-subsidised rental housing produced by the Housing Finance and Development Centre of Finland (ARA).

The external architecture of the buildings is strongly guided by the city’s ambitious plan for the Kuninkaantammi district. Building designers were eager to join the city in creating such a visually unified district with its own unique identity. The area’s external architecture is characterised by a uniform scale, pitched roofs of varying shapes and sizes, construction directly onto the street, fully retracted balconies and a lively but controlled use of colour. The colours are reminiscent of the rhythmic pitter-patter of Central Europe’s medieval cities, which served as a distant inspiration. To make the buildings more interesting, the colour demarcations of the facades are intentionally out of sync with the building masses. The facade colours continue on the bottom surfaces of the eaves. The free-folding form of the roofs is a key part of the site’s architectural expression.

The frame is wood, except in the basement and garage, and constructed from large elements. The intermediate floors, balcony elements and indoor staircases are all made of wood, the balcony slabs are CLT. All parts of the buildings are made in Finland, with Finnish materials. The exterior cladding of the building facades is mainly horizontal wood panelling. In contrast, the facade facing Taidemaalarinkatu street uses vertical panelling. The roofing material of the residential buildings is felt, and the auxiliary building has a green roof. Special attention was paid to the yard’s quality and the absorption principles for urban runoff water.

The project is part of the “Kehittyvä kerrostalo” (The developing multi-storey building) program of the City of Helsinki. Using buildings of similar size and shape, the program compares the properties of wood and concrete construction during the design and construction phases and during actual use. Conveniently enough, the reference site is located on the neighbouring plot.

Residential buildings with sizes and layouts similar to A-Kruunu’s wooden buildings were constructed in concrete almost at the same time. The research also includes a customer satisfaction survey to discover eventual differences in how people actually feel about living in wooden vs. concrete buildings. The results will be published later this year. According to Mika Airaksela, Managing Director of the site’s contractor Rakennusliike Reponen Oy, it is already clear that the wooden building’s carbon footprint for the construction period will be about 30 percent lower when the entire building – including foundations and earthworks – is taken into account. The projects differ little in terms of total time spent: wooden multi-storey buildings currently require more time in the design stage, but concrete buildings are slower to build.

Kuninkaantammi is A-Kruunu’s first wooden construction. A-Kruunu wants to continue wood construction in the future, as evidenced by the two entries it submitted to the design competition for a wooden housing block in the Kivistö district of Vantaa. The promotion of wood construction is an important goal, as are the development of affordable rental housing and the furthering of housing innovations.

Project in brief
Location: 
Helsinki, Kuninkaantammi
Client: 
A-Kruunu Oy
Size: 
Volume: 21 652 br-m3, Gross floor area: 3 738 k-m2, Total area: 6 091 br-m2
Structural design: 
Wooden structures: Sweco Rakennetekniikka Oy, Concrete structures: Insinööritoimisto Kai Kakko Oy
Special design: 
Electric design: Optiplan Oy, HVAC design: Optiplan Oy
Contractor: 
Rakennusliike Reponen Oy