Optimizing daylight and aesthetics in energy renovations; a parametric approach to Swedish multifamily housing

Abstract

This thesis explores how energy renovations of Swedish multifamily residential buildings can be designed to enhance interior daylight quality, thermal comfort, and architectural value, while still meeting upcoming regulatory demands. With the new EU EPBD and the revised Swedish building regulations in BBR coming into force, a large portion of the existing residential building stock will require renovation. However, conventional renovation methods often lead to decreased architectural quality and worse interior conditions. The aim of this thesis is to develop design strategies that balance energy performance requirements with qualitative spatial and aesthetic values. The methodology combines literature studies, project references, interviews, and simulation-based parametric analysis. Two residential buildings in Gothenburg serve as case studies: Kv. Tuppfjätet, a 1930s landshövdingehus where original character is prioritized, and Siriusgatan, a 1970s million program building targeted for transformation. Through a parametric workflow using Rhinoceros and Grasshopper plugins, daylight and energy performance were assessed using metrics such as Daylight Factor, Useful Daylight Illuminance, Spatial Daylight Autonomy, View-Out, Energy Use Intensity, and overheating risk. The results show that a combination of minor architectural adjustments—such as improved window niches, optimal window depth, and reflective materials—can significantly enhance daylight access in preservation scenarios. For transformative cases, strategies like optimized window sizes, shading elements, and transparency levels proved effective in improving both energy use and spatial quality. These interventions allowed for better alignment with both daylight regulations and energy targets, without compromising architectural integrity. The study concludes that integrating simulation-based analyses with architectural design tools can support a more holistic and qualitative approach to energy renovations. It demonstrates that well-informed design strategies can improve interior conditions as well as restore or enhance the architectural identity of aging residential buildings, while still meeting enhanced regulatory energy performance demands. The strategies proposed in this work can be adapted and applied broadly, serving as a methodological guide for architects navigating complex trade-offs in future renovation projects