An energy-efficient trio of multi-storey timber-frame flats in the Jyväskylä suburb of Kuokkala have won this year's Wood Prize, awarded by Finland's Wood Information Centre.

Not to be confused with the Wood Awards, the Wood Prize was established in 1994 to recognise outstanding Finnish wood architecture which advances research and development in timber construction techniques. Beating off stiff competition from nine other nominated timber-based projects, the Puukuokka Housing Block, which was also awarded the Finlandia Prize earlier this year, was victorious once again thanks to its pioneering modular system.

Sitting eight storeys high, Puukuokka is built from prefabricated volumetric modules of cross-laminated timber, which slot together on site.

The CLT design, conceived by architect and designer Anssi Lassila of OOPEAA and commissioned and built by Lakea, has multiple advantages. The CLT's substantial insulating qualities allow the temperature of the individual apartments to be controlled independently from that of the spacious hallway and atrium; pipes for heat, water, electricity and ventilation could be easily integrated into the wall structure in the hallway; the CLT also made it possible to have a primary load bearing structure and frame for the building's entire 26 metres; and last but not least, it was possible to cut construction time on site down to six months, limiting damage from exposure to weather conditions.

'The goal was to create a hybrid building that combines the sense of privacy of a single-family dwelling and the semi-public character of the shared spaces of an apartment building,' says Lassila of the project's goal.

As well as its ground-breaking construction, Puukuokka also pilots an innovative lease-to-own financing strategy that aims to support social sustainability by promoting stable communities.