Assessing cooling–lighting trade-offs in a low-income Jordanian housing archetype under climate change and heat waves

This study examines climate-robust passive envelope strategies for a low-income dwelling in Irbid, Jordan. The analysis covers a heatwave (23–29 July 2023) and projected future climates (2020, 2050, 2080). Using a BIM-based model, four scenarios were simulated: (S1) baseline, (S2) a trade-off strategy, (S3) S2 plus a ventilated cool roof, and (S4) S2 plus removal of west windows. The performance metrics were cooling loads, lighting loads, discomfort hours, and daylight indicators (sDA, UDI, ASE). S2 reduced cooling load, but increased lighting load and glare. This highlighted the trade-off mechanism. Adding a ventilated cool roof (S3) gave the most robust results across future climates. It reduced cooling energy by up to 48 % and delivered the most consistent reduction in discomfort hours. S1 was still the most optimal strategy, maximizing daylight while minimizing excessive ASE. In contrast, removing west windows (S4) reduced overheating but led to the poorest daylight outcomes. From 2020 to 2080, static shading lost effectiveness. Discomfort hours increased sharply across all scenarios and operative temperatures. sDA declined, despite minor improvements in ASE and UDI under S3. These findings indicate that passive static shading alone cannot guarantee long-term comfort in extreme heat. Higher operative temperatures of 31–32 °C are expected by 2080. This study is the first to quantify the trade-offs between cooling and lighting in low-income housing across current and projected climates, advocating for dynamic shading or ventilated roof strategies combined with balanced window-to-wall ratios and daylight-responsive lighting. This approach offers a low-cost, climate-adaptive solution that enhances comfort and reduces energy demand under future warming scenarios.