Measured performance of 12 demonstration projects—IEA Task 13 “advanced solar low energy buildings”

This paper presents the results obtained from measurements and experiences gained from interviews on 12 advanced solar low energy houses designed and built as part of the International Energy Agency (IEA) Solar Heating and Cooling Programme—Task 13. Three years after the IEA Task 13 formally ended, the results were collected by means of questionnaires sent to the former participants in Task 13. A small IEA working group was responsible for collecting and processing the results. The paper gives a brief presentation of the houses and the applied energy saving measures. Measured and expected energy consumptions and indoor climate conditions are compared and differences explained. Special innovative installations and systems are described and evaluated. In general the measured energy consumption was higher than the expected values due to user influence and unforeseen technical problems but still an energy saving of 60% compared with typical houses was achieved. Prevention of overheating requires special attention also at northern latitudes. Interviews with occupants revealed the need to explain the building’s behaviour thoroughly to its users and elaboration of user manuals.