A fortochka (Russian: фо́рточка, IPA: [ˈfortətɕkə] (listen)) is a small ventilation window. It usually spans the frame of one window pane and opens on hinges independently of the whole window. Fortochkas are in common use in Russia, other post-Soviet states (Ukrainian: кватирка, kvatyrka), and Finland (Finnish: tuuletusikkuna).
A fortochka can be used for ventilation during cold winters, when opening a whole window would be impractical for heat conservation purposes.
- Martinot, Eric (1997). Investments to Improve the Energy Efficiency of Existing Residential Buildings in Countries of the Former Soviet Union (1. print. ed.). Washington, DC: World Bank. p. 117. ISBN 0-8213-4057-3. Retrieved 19 February 2013.