Evaluating the effectiveness of approved document o in mitigating overheating in buildings: a focus on modern methods of construction

In recent years, the adoption of modern methods of construction (MMC) to help achieve net-zero goals and enhance construction efficiency has risen. However, concerns have emerged regarding its thermal performance and effect on occupant comfort, particularly in an era where building overheating has become an increasing risk. This challenge has drawn stakeholders’ attention, including the UK government which has published a regulatory framework to mitigate the adverse effects of building overheating. This study seeks to evaluate the effectiveness of Approved Document O in mitigating overheating in modern buildings. The study employed multiple method qualitative research, including a comprehensive literature review, a desk study of existing regulatory framework and semi-structured interviews among 6 participants to assess the overheating risk in modern buildings and the effectiveness of regulatory frameworks. Findings from the literature review identified key factors contributing to overheating, such as high ambient temperature, solar radiation, design and construction practices, and occupancy behaviours. Thematic analysis of interview data highlighted inappropriate ventilation as the primary cause of overheating, regardless of the construction method, with lightweight materials and energy-efficient building posing additional challenges. The interviewees emphasized the necessity for consistent regulatory frameworks across all construction methods and the importance of passive design strategies. The study contributes to the understanding of regulatory effectiveness of Approved Document O and offers recommendations for improving overheating mitigation in MMC buildings.