The contribution deals with the indoor air quality (IAQ) in residential prefabricated panel houses, which represent a significant proportion of the housing stock in the Czech Republic. Ensuring the health and comfort of users is a phenomenon of present time in accordance with the principles of sustainable development. Almost two thirds of building occupants suffer from the symptoms of Sick Building Syndrome (SBS). Concentration of pollutants in indoor environments increases due to increasing of airtightness of the building envelope and due to insufficient ventilation. The main source of contaminants is the human and its every-day activities such as breath, skin respiration, flatus and using cosmetics or perfumes. Building materials, furniture and equipment of building are also a source of harmful emissions. Experimental measurements were carried out in autumn/winter 2016 in characteristic apartment of prefabricated panel house (Ostrava, Czech Republic). The high-performance AS-MLV-P2 MEMS (Micro Electro Mechanical System) gas sensor was used for VOC detection. The obtained levels of volatile organic compounds are expressed in the values of CO2 equivalent [ppm]. The obtained results are described and analysed in this paper.