The continuous increase of the building energy demands in terms of energy efficiency in order to ensure that the interior of energy-efficient buildings with the large glazed areas. This glazed areas supports the energy demand decrease and illumination of the interior by solar gain in the winter period, but this causes a problem in achieving the required quality of the indoor environment in summer due to changes in climatic conditions. Certain human activities like production of grrenhouse gases have been identified as primary causes of ongoing climate change and increasing of thermal load, often referred to as global warming, also in Slovakia. The investigation in master thesis (year 2013) was realized with connection to the summer overheating of the indoor environment of low-energy buildings was based on the measurments. The results of the investigation was that with the climate change it will be necessary to look for alternative variants of optimization solutions that would eliminate the impact of unfavorable conditions on the internal microclimate of wooden structures. From this point of view, the dissertation thesis deals with the quantifying the influence of different types of optimization solutions of passive thermal protection against summer overheating of indoor environment. The part of the dissertation thesis was implementation of a measurement set of the internal environment parameters of selected wooden structures, the creation of simulation models and create wheather databases with application of climate change in Slovakia. Qunatification of the optimization solutions impact was based on the monitoring changes in the internal air temperature of simulation models before and after building envelope optimization. The change of interior environment was expressed by the decrease in the number of hours when the internal air temperature Ti exceeded the temperature of 26°C (Ti > 26°C) and monitoring the impact of model optimization on the thermal comfort parameters (PMV and PPD index).