The Round House is a cylindrical commercial building owned by Ilmarinna pension insurance company in Helsinki Hakanio since 2000, designed by Heikki and Kaya Siren. The Round House is located at Siltasaarenkatu 18-20.
The Round House is the only building in the block between Siltasaarenkatu, Eläintarhantie and Porthaninrinne. Previously there were several wooden houses and several stone houses, including the Wendt house designed by the master builder Heikki Kaartinen and the Berggrund housing company (1903) designed by the architect Gustav Estlander.
The building was completed in 1968 as an office building of the National Joint Stock Bank. Outside the building there are three kiosk buildings, which initially worked as the largest bank in Finland . However, maintenance was discontinued shortly after the 1970s, when demand declined.
In 2002-2004, the house was renovated, modernized construction technologies and made the rooms light and comfortable to convert. The total cost of the renovation was 30 million euros. One of the architects involved in the renovation project was Jukka Siren, son of the architects who designed the building. The apartment area of the building is 35,654 m², of which 25,500 m² can be rented.
The round house is protected in terms of outer shell, entrances, yard and staircases. During the renovation, almost all internal structures have been renovated, and at the request of the City Museum only one group of office space remains in its original 1960s appearance.
In front of the main door of the round house is a steel work of art created by the sculptor Hannu Siren, a spherical symbol with a diameter of three meters . Hannah Serena is the son of Heikki and Kaya Serena. The work is part of Nordea's art collection (situation 2005).