Jean and Aino Sibelius and their three daughters moved to Ainola with one servant girl, who had to live in a room of about five square metres.

As for the children, Eva was 11 years old, Ruth 10 and Katarina barely 2 years old. During the first years the girls were educated by their mother at home. The living space of the family consisted of a downstairs area, slightly less than 190 square metres. It was only seven years later that additional space became available, when the upper floor was made habitable. After the extensions to the kitchen and the servants' room, the heated area of Ainola increased to over 330 square metres. By this time Sibelius's two youngest daughters were born: Margareta was born in 1908, and Heidi was born in the course of the renovations to the upper floor, in the spring of 1911.

In his biography of Sibelius, Erik Tawaststjerna says that Ainola is a "symphony in wood". However, immediately after the move in 1904 the "symphony" was in many ways different from how it looks today. This can be seen from a contemporary drawing. 

The Christmas issue of the magazine AIKA, 1904: Ainola and the first snow of winter, seen from the yard. The sledge is being pushed by Eva or Ruth; the child in the sledge is probably little Katarina.

The upper floor was an unfurnished attic which received light only through small lattice windows. The house had the colour of its timbers. These were covered over with lighter-coloured boarding ten years later. The shingle roof was covered over with red bricks in 1932.

The entrance porch was still small. The gable wall facing the yard was straight, as the kitchen and the servants' room were smaller than today. The door to the kitchen opened into the yard. In the eastern corner of the house was a covered porch which could be entered through a pantry leading to the kitchen. Today, where the porch was originally, one can see the washing alcove that served Sibelius's last bedroom and study. There is also an additional staircase to the upper floor.