**Abstract**

Increasing the construction of wooden apartment buildings has its place as part of preventing climate change. This chapter aims to explore the possibilities of expanding the construction of wooden apartment buildings on plots owned by the City of Helsinki in the Mellunkylä area by developing a series-produced wooden apartment building concept suitable for complementary construction—The Noppa concept. The sustainability of this approach is considered from the perspective of materials, construction methods, adaptability of the designed spaces, and housing design flexibility. In this study, the Noppa wooden apartment building concept with cross-laminated timber (CLT) elements has been developed varying in its facilities and architectural design features through architectural modeling programs to be used for complementary construction. The research findings are based on a theoretical approach that has not yet been practically tested but is proposed considering existing construction practices that need further investigation. It is believed that this chapter will contribute to the spread of wooden apartments to achieve a low-carbon economy as one of the key tools in tackling climate change problems. Particularly, proposed architectural design solutions will contribute to decarbonization of buildings as well as zero energy building (nZEB) approach.

**Keywords:** apartment building, zero energy buildings (nZEB), architectural design, timber/wood, CLT, Finland
