The concern with indoor air pollution has been growing as a serious social problem since the 1990s in Japan, the Ministry of Health, Labour, and Welfare has established guidelines for addressing indoor chemical substances, and the amended Building Standards Law has restricted the use of building materials containing formaldehyde and required rooms to have ventilation equipment. The purpose of the present study was to examine the effects of differences in the building material specifications on indoor air quality. Two student dormitories were selected for investigation: a student dormitory remodeled using interior finishing materials containing low- formaldehyde substances; and a dormitory built according to conventional specifications. Indoor formaldehyde concentrations were lower than the guideline established by the Ministry of Health, Labour, and Welfare, even in summer under high-temperature conditions, due to the implementation of the policy to reduce chemical substances in building materials and the effects of the restrictions. However, problems were identified in terms of increases in indoor concentrations after installation of furniture, and mean concentrations during sleeping hours. Ventilation performed by residents effectively reduced mean formaldehyde concentrations. To maintain appropriate indoor air quality, it is important for residents to pay attention to ventilation and room furniture, and their lifestyle, in addition to the selection of building materials.