A mixed-method comparative analysis of sustainable roofing solutions for thermal and energy efficiency in residential buildings in Saudi Arabia

There is a growing need for practical solutions that are climate responsive, particularly in hot arid regions like Saudi Arabia. This study explores the potential of four sustainable roofing strategies, namely: green roof (GR), cool roof (CR), solar PV roof (SPV), and roof canopy (RC), to reduce rooftop surface temperatures and improve energy performance of residential buildings considering three cities that represent three climatic zones in Saudi Arabia. The study used a combination of qualitative and quantitative methods based on a survey of residents, and thermal performance simulations of a case study. The survey results showed that all of the investigated roofing strategies were positively perceived by residents, with weighted average agreement levels ranging between 3.8 and 4.4 out of 5.0. The thermal simulation results showed that the investigated roofing strategies offered a reduction in roof external surface temperature, which was more significant in GR, where a reduction of 28% to 52% was observed compared to the reference flat roof (FR). As for energy consumption, GR showed a higher potential, where a reduction of 20% was observed. The findings highlight the importance of informed decision-making and innovative sustainable design strategies in overcoming thermal design challenges posed by extreme hot climatic conditions.