Solar accessibility at the neighborhood scale: A multi-domain analysis to assess the impact of urban densification in Nordic built environments

Abstract

This article presents the preliminary stage of a wider study aiming to determine the effect of densification processes on solar accessibility in urban environments through the use of a multi-domain approach. Here, a set of solar accessibility analyses are conducted for the actual and future scenarios at the three urban domains of (i) outdoor, (ii) envelope, and (iii) indoor, using as metrics (i) hours of direct sunlight on the 21st of March, (ii) seasonal and annual irradiation, and (iii) average daylight factor. The approach is applied to a case study conducted at high latitude (Trondheim, Norway; latitude 63.43° N) for the new extension of a university campus. The results show a reduction in solar accessibility for all the three tested domains when the new project is inserted into the plot. Almost two-thirds of the outdoor area fails to comply with the recommended target of five hours of direct sunlight access, while none of the 21 analyzed facades is considered suitable for the installation of active solar systems. The indoor daylight level is also severely compromised, with all four ground floors of the tested buildings falling short of the target 2% average daylight factor in the future scenario. However, the selection of a highly reflective material as the finishing for the newly designed buildings can compensate for the losses caused by the new buildings’ masses. This study demonstrates how a set of solar analyses in different urban domains can identify the critical aspects of a densification process in its preliminary stage and open future possibilities for urban morphology and buildings’ design optimization.