Daylight Performance in Urban Residences in Greece: Assessing EN 17037:2018 compliance and improvement strategies

In 2018, the European daylight standard EN 17037:2018 was published to encourage designers and developers to assess and provide sufficient daylight in buildings. However, the revision process by the European Committee for Standardisation identified that the recommendations for daylight provision are often challenging to achieve; therefore, the technical committee for the daylight working group, the CEN/TC169/WG11, was established to examine the issue. While several studies have recently assessed daylight performance in northern latitudes, it has been acknowledged that southern latitudes face challenges that differ from those in Northern Europe. The reason is that there is a lack of information regarding the standard’s suitability for the regions in Southern Europe. The purpose of this master's thesis is to examine the application of the European Daylight Standard EN 17037:2018 in a Greek urban residential context as well as to discuss potential modifications to the standard that could enhance overall daylight quality. The study analyses daylight factors (D) and illuminance levels (E) in six residential buildings with a total of 235 rooms assessed. Simulations were used to evaluate the daylighting conditions in the subject buildings, considering variables such as building orientation, window-to-floor area ratio, and urban density. The research results indicate variations in daylight performance, attributed to design principles, such as wide balconies, window orientation, building shape, as well as national building code and planning regulations. Additionally, measures to improve daylight quality in Greek residential buildings are discussed with the intention of informing future versions of the Greek building code as well as other applicable daylight standards.
The European daylight standard, EN 17037:2018, was introduced in 2018 to encourage designers and developers to assess and ensure adequate daylight in buildings. However, the European Committee for Standardisation’s revision process identified that the recommendations outlined in the standard are often challenging to achieve. Southern European countries, in particular, face distinct challenges compared to northern Europe, largely due to the lack of data on the standard’s applicability in southern regions. This study assessed the daylight performance of six residential buildings in Thessaloniki, following the requirements set by EN 17037:2018. It also aimed to determine whether the current daylight criteria are suitable for the Greek urban context and explored potential modifications of rules and regulations to improve overall daylight quality. Radiance-based simulations were performed using the CIE overcast sky model for the daylight factor method and with Thessaloniki’s local weather data for daylight provision analysis. The results indicate that achieving “Level Medium” and “Level High” for daylight performance is challenging, even in low-density residential areas. The findings underscore that daylight performance in Greek urban settings is influenced by multiple factors, including urban density, the surrounding environment, architectural design characteristics and building orientation. However, there are no current mandatory regulations that can address these factors to improve daylight availability. A key finding is that the daylight standard must be flexible and region-specific, especially in Southern Europe, where challenges such as excessive sunlight and overheating are more pressing than daylight availability. High daylight performance criteria may not be appropriate for these regions. Therefore, the standard should be revised to account for cultural, climatic and occupant behaviour factors. Additionally, it is crucial for architects and engineers to fully un