Influence of the orientation on the optimal glazing size for passive houses in different European climates (for non-cardinal directions)

The construction sector accounts for a major part of European energy stock, so enhancing the energy performance of building is becoming more and more important. The improvement of the energy performance of building can be achieved through passive design measures and these have to be made in early design phases. Among them is the position and size of glazing in buildings. The study focuses on different deviations of the main glazed façade of a single-family building from the south and how this affects the energy flows through the glazing. The study was conducted for different European climates that are classified Cfb according to the Köppen-Geiger classification, namely Ljubljana, Budapest, Munich and Stockholm. The calculations were made for the orientations: WSW, SW, SSW, S, SSE, SE, ESE and for different U-values and g-values of the glazing. For each orientation and glazing properties type the optimal share of glazing (AGAW) was calculated. The optimal share of the glazing of the main façade for the climate of Ljubljana is between 38 and 42% of the façade, depending on the glass properties of the triple glazing windows. By tilting the main façade, the optimal share of glazing decreases, for example between 0 and 20% of glazing for the ESE orientation or between 0 and 24% for the WSW orientation. The optimal glazing areas remained very similar for Budapest and it is also possible to forecast the optimal areas for climates that have different cooling and heating requirements but similar solar gains for separate orientations (Stockholm and Munich). This means that the results are also applicable for other places that are classified as Cfb according to the Köppen-Geiger classification.