Mitigating overheating in renovated Danish residential buildings: The potential of implementing louvred openings

As outdoor temperatures rise and heat waves become more frequent, the absence of overheating prevention measures and impending renovations pose challenges to summer thermal comfort in residential buildings. Manual window opening, as the preferred method to address high temperatures, comes with concerns such as increased safety risks, potential noise disturbances, and vulnerability to adverse weather conditions. To address this, a combined system of louvre and ventilation hatches (named louvred opening hereafter) is proposed as an alternative to energy-intensive air conditioning and traditional window ventilation. This system enables ventilation even during occupants’ absence, adverse weather conditions, and potential noise disturbances. The study investigates the implementation of louvred openings in existing residential buildings and their potential to mitigate overheating during the warm season. The systems’ impact on load-bearing structure, architectural value, daylight availability, and overheating is analysed using the Danish building stock and two Danish case study buildings. Additionally, influential factors such as occupant behaviour and opening characteristics are scrutinised in the overheating study. The findings revealed that the load-bearing structure and the architectural value of post-1950 Danish buildings are well-suited for incorporating louvred openings. However, placing louvred openings in existing window spaces significantly reduces daylight availability, indicating that buildings from earlier construction periods with smaller glazed areas may necessitate adding new external wall openings. Nevertheless, louvred openings demonstrate superior performance in mitigating overheating compared to conventional window ventilation, especially when occupants utilise night ventilation effectively. • Louvred openings to mitigate overheating in renovated residential buildings. • Practical implementation of louvred opening during renovation studied. • Influence of louvred openings on daylight availability and overheating simulated. • Louvred openings suitable for implementation in buildings built after 1950. • Louvred openings can reduce overheating when leveraging night ventilation.