The article will deal with the analysis of measured data on a plastic window with thermal insulating triple glazing, which is suitable for low-energy or passive houses. The window was installed in 2011 in the test laboratory of the Department of Building Engineering and Urban planning, Faculty of Civil Engineering, University of Žilina (Slovakia), where it was tested under standard indoor climate conditions and real outdoor climate conditions. Surface temperatures on the frame friezes and glass system and heat flux density were recorded at a five-minute time step. In 2020, the window was removed from the laboratory and subsequently tested in a climate chamber. This paper will present the results of these measurements in terms of heat flow density waveforms, heat transfer coefficient, and total solar transmittance through the glazing. Subsequently, a simulation model of this window will be created in the environment of a computational program and its verification based on the measurements will be carried out. A series of calculations will be performed on the tuned model and analyses of the results and comparisons will be presented under the same climatic conditions as during the real measurements recorded by the meteorological station.

The construction industry's focus on a low-carbon economy will result in the need for a deeper examination of natural-based building materials. From an environmental point of view, the benefits of these materials are undeniable. However, it is necessary to consider their shortcomings in other areas of design in terms of building thermal engineering. This article observes and evaluates a wall designed for a wooden building with almost zero energy demand in year-round operation and subsequent assessment in confrontation with a different composition, seemingly more advantageous in thermal resistance and humidity regime. These assemblies are under long-term examination within the pavilion research of the authors' workplace, in laboratory conditions from the interior side. At the same time, they are exposed to the realistic boundary conditions of the external environment. The paper includes an environmental assessment of two compositions, variating in the used material. The research shows that the wall composition of natural materials is more advantageous from an ecological perspective and can also show favourable effects in terms of temperature and relative humidity regulation.