Daylight provision requirements according to EN 17037 as a restriction for sustainable urban planning of residential developments

Abstract

The attempt at a more sustainable land use by increasing urban density may have a negative effect on the daylighting of residential buildings. In densely built areas, obstructions generated by the surrounding buildings can substantially reduce the available amount of daylight, causing poorly daylit spaces and a less healthy indoor environment with higher electricity consumption as a consequence of artificial lighting. European standard EN 17037, Daylight in Buildings, was established in 2018 to ensure appropriately daylit spaces. In this paper, a three-step methodology was developed to investigate the relationship between certain urban planning parameters and the daylighting of a typical room defined by specific (Slovenian) legislative restrictions about its geometry and minimum required window to floor area ratio, in order to establish the maximum densities of residential developments still fulfilling the minimum requirements for daylight provision defined by EN 17037. The results show that a relatively low urban density is required to fulfil the stipulations for minimum daylight provision for the deepest permissible room according to the Slovenian legislation. The impact of the development floor area ratio on the daylighting potential of buildings was identified as significant, followed by the site coverage, development layout, and building typology. Furthermore, the developed methodological approach clearly demonstrates a substantial potential for application in urban planning, with indoor daylight environmental conditions being linked to the planning of residential developments in the earliest stages of the project.