An analytical method for volatile organic compounds (VOC) which employs a multisorbent sampler containing, in series, Tenax-TA, Ambersorb XE-340, and activated charcoal is described. The method was evaluated in the laboratory and was used to measure concentrations of VOC at a school and an office building. The sampler quantitatively collects compounds spanning a broad range of boiling points, including highly volatile solvents. The overall precision of the method is better than 10% and often better than 5%. The composition and concentrations of VOC in the two, approximately five-month old, nonresidential buildings were similar and also similar to the composition and concentrations in typical residential indoor air. Concentrations of VOC were measured at two ventilation rates in both nonresidential buildings, and the data were applied to a single-equation, mass-balance model. Apparent specific source strengths for VOC approximately doubled with a six-fold increase in ventilation rate.