Joensuun Pihapetäjä apartment building is currently the most energy efficient wooden apartment building in Finland. The energy class of the building is B (99 kWh/m²/year). The six-story building has a basement made of concrete and five floors made out of CLT (Cross Laminated Timber). Joensuun Pihapetäjä consists of 40 flats and total living area is 1730 m². The energy efficiency is gained by new innovative HVAC-technologies as well as with structural solutions. The building is owned by a private owned foundation called Karjalaisen Kulttuurin Edistämissäätiö KKES, who is renting the apartments for the citizens.
The energy efficiency is gained by new innovative HVAC-technologies as well as with structural solutions. HVAC-technologies include for example, a hybrid heat exchanger. The heat exchanger system recovers heat from the black and grey waters to heat up the hot water. The system has a 50% efficiency rate. The building has 100 m² solar plant installed on the roof with 15.9 kWp performance. The panels have a theoretical potential for 13 MWh annual production of electricity.
Every apartment has its own ventilation unit with heat recovery up to 80% efficiency. Structural solutions include innovative solutions, for example semi-warm staircases which significantly saves energy needed for heating. Air tightness was measured from eight apartments with the variation between 0.6-1.0. Thus the theoretical envelope airtightness (q50) of the building is 1.0.
More information in Finnish: www.joensuunpihapetaja.fi