The contribution reports on a simulation study of indoor air quality in relation to different ventilation rates specified for 3 categories of the indoor environment according to EN 15 251. Indoor air quality and energy management are often at the opposite ends of the building management spectrum. The buildings are polluted by occupants of the building themselves. The indoor air quality can be expressed at the required level of ventilation or Carbon Dioxide (CO2) concentration. Actually, the indoor air quality is influenced by emission from building surface materials and furnishing, occupants and their activities. VOCs play an important role in the indoor air quality evaluation process. VOC emissions adversely affect both occupant comfort and health. Most of the health hazards associated with VOC emissions occur during the first few weeks of building use. The Indoor Air Quality Emission Simulation Tool developed by National Research Council is used for simulating the VOCs emission impact of selected materials based on the amount of materials used and the ventilation rates in a model room, in this case study. IA-Quest predicts the emission of VOCs from building surface materials and furnishings, helping to select low-emission materials and effective ventilation strategies. The results showed the benefit of removing the increased amount of TVOC generated in time of the unoccupied period. The differences in TVOC concentrations were not obvious between two higher ventilation conditions (2.00 and 1.40 l/s.m2). More significant difference was estimated between categories A, B and category C (0.80 l/s.m2).