A 3-year follow-up of indoor air quality and comfort in two energy-efficient houses

In order to improve the knowledge of the indoor environment quality of energy-efficient buildings, a 3year follow-up study was carried out in two wooden-framed low-energy single-family houses in France. Several indoor air indicators and indoor environmental parameters were measured during seven weeks in total from the pre-occupancy stage up to three years of occupancy. Questionnaires were used for each investigation to record the family activities and perceived comfort of occupants. The ventilation systems presented some shortcomings, including the failure to reach the designed exhaust air flow rate and induced occupant dissatisfaction. Regarding the measured pollutants, both houses didn't present any specific indoor air pollution. The variability of indoor air quality over time was explained by the high emissions from the new building materials, products, and paints during the first months after completion and then more episodically by human activities during occupancy. Regarding the thermal comfort and even if occupants were globally satisfied, overheating and under-heating were observed. According to our results and in order to guarantee the health and the well-being of occupants in these buildings, it would be useful to integrate the solar shadings at the very first stage of the building design, to design more quiet, user-friendly and robust ventilation systems and to implement mandatory inspection as well as frequent maintenance by professionals and finally to promote the labelling of low-emitting construction and decoration products, furniture and consumer products. (C) 2014 Elsevier Ltd. All rights reserved.