Glazing's techno-economic performance: A comparison of window features in office buildings in different climates

The use of glass in buildings has a considerable impact both on comfort levels and energy performances, since glazed components protect from external environmental conditions, provides daylighting, view and also ventilation if they are openable. Starting from the second half of the 19th century, the architectural design used to give an increasingly important role to the glass, particularly in non-residential buildings, almost in every kind of climatic conditions. In this context, the present work aims to assess the techno-economic performance of glazing with various thermophysical and optical properties and different glass/wall ratios, coupled with internal/external shading systems, considering the application on an office building in 3 different representative European climates. The obtained results demonstrate that there is a negative impact of solar gains on the yearly energy balance of modern office buildings, where thermally-insulated envelopes enhance overheating even in cold climates. Because of this, the most reasonable solution to decrease the yearly energy consumption is to limit the amount of glazing or to use external solar shading devices. It can be also stated that, under a global-cost perspective, the best cost-effectiveness is achieved using a solar control glazing without any shading. If, however, the cost of discomfort due to glare is accounted, the use of solar shading devices emerges as the most convenient option in all analysed cases.