## 1 Introduction
### Scientific Studies Using the Building Energy Simulation Method
Based on the results of multi-variant calculations, it was found that for all orientations and climatic conditions, the window to wall area ratio had the greatest impact on both the environment and investment costs. The U-value was found to also have a significant environmental impact for larger windows in cold climates and smaller windows in warm climates. Additionally, larger windows or smaller windows that have a high solar heatgain coefficient (SHGC) are recommended in colder climates. On the contrary, in warmer climates, smaller windows or larger windows with a low solar gain are recommended. The University of Victoria (Canada) is renovating 49 non-residential buildings to reduce their energy use and greenhouse gas emissions. The campus buildings were largely constructed before building energy regulations were introduced. [PERSON] et al. [PERSON] et al. (2018) developed a methodology to assess the possibilities of achieving potential energy savings and performed energy simulations of three selected buildings in EnergyPlus version 8.8. The thermal characteristics of the partitions based on the UA coefficient (U-value multiplied by the partition area A) was the main element that was analysed first. The scope of the computer simulations also included the characteristics of double-, triple- and quadruple-glazed windows. The main conclusion from this study was that the significant impact on the thermal performance of buildings came from the increase in the WWR value. Buildings with large-format glazing provide their occupants with much greater access to daylight. However, this is very often associated with reduced energy efficiency. [PERSON] et al. [PERSON] et al. (2018) examined a six-storey office building with a height of 21 m and a usable area of 6177 m\({}^{2}\) located in Gothenburg (Sweden). IDA ICE 3.0 dynamic energy simulation software was applied as the research tool. Three WWR values of 0.3, 0.6 and 1.0 were analysed to determine the influence of the glazing area on energy consumption. Below are some of the most important and rather obvious conclusions from this computational analysis:  
* It is recommended to use glazing with a low heat transfer coefficient, because it significantly reduces energy consumption for heating and at the same time does not significantly change the energy demand for cooling;
* The SHGC coefficient, which determines how much solar radiation falling on a window is transmitted into the room, has a key influence on the energy demand for cooling;
* The most effective way to reduce cooling demand is to use shading devices. [PERSON] et al. [PERSON] et al. (2018) estimated the service life and the amount of CO\({}_{2}\) emission reduction of apartment buildings located in South Korea. The aim of this investigation was to select low-emission technologies for residential buildings using so-called green technological solutions. In this study, 36 types of alternative durability strategies were considered based on a 100-year building service life. The analysis included three types of glazing: metallic double-glazed windows, plastic double-glazed windows and metallic quadruple-glazed windows. The results showed that the quadruple-glazed windows with a 6 mm air gap between the panes achieved the greatest reduction in carbon dioxide emissions. An examination of the differences between the energy demand of a building using a simplified and a detailed method of calculating the optical-thermal parameters of windows was performed by [PERSON] et al. [PERSON] et al. (2018). The reference object of this study was a single-family house located in Tallinn (Estonia). The calculations were made for windows with triple and quadruple glazing and assumed different glazing areas on the west and south elevations. It turned out that the energy demand for heating was lower by up to 7%, while the demand for cooling was higher by 23%, when simplified models were used.