The Aira building from 1926 was the first large apartment block in the city of Jyväskylä and the first bigger assignment for the Aalto office. Architect Aino Marsio joined the office during the design process of the building in 1924 and the Aaltos got married shortly after that.

This three-storey brick building contains eighteen identical flats, comprising two rooms, a kitchen, bathroom and hall, grouped around three stairways entered from the courtyard, which was planned as a garden. A special feature of the design of the dwellings were the semi-circular recesses for hanging coats, and a small fake perspective in the passage between the two rooms.

The sober façade, which prefigures the Aaltos’ Rationalist apartment blocks from the 1930s, is given character by subtle details, such as the Pompeiian colouring of the eaves, spiralling downspouts, specially designed lanterns in the doorways, the tabernacle form of the dormer windows, and the wedge-like passages between rooms in the interior.