Date of Defense

25-6-2026 9:00 AM

Location

F1-1124

Document Type

Thesis Defense

Degree Name

Master of Science in Architectural Engineering

College

College of Engineering

Department

Architectural Engineering

First Advisor

Young Ki Kim

Keywords

roof retrofitting, cool roof, green roof, insulation, energy consumption, thermal comfort, UAE, residential buildings, hot arid climate

Abstract

Due to the United Arab Emirates having a hot arid climate, residential buildings experience high cooling demands. A major building element for solar heat gain through buildings are roofs. This study evaluates roof retrofitting strategies for existing low rise residential villas in Al Ain. The aim is to reduce cooling energy consumption, improve indoor thermal comfort, and support compliance with current UAE envelope performance requirements. A case-study villa (Majlis space) was monitored during the peak summer period. Indoor temperature data were recorded using a HOBO device and used to derive an operational HVAC schedule for simulation input. The baseline model was developed in DesignBuilder and calibrated/validated against measured electricity-bill consumption and roof surface temperature checks using a Testo thermal imaging device, following accepted calibration tolerances (e.g., ASHRAE Guideline 14 thresholds). Five retrofit scenarios were assessed: cool roof, green roof, additional insulation, cool roof + insulation, and green roof + insulation. Relative to the baseline cooling demand (6,022 kWh for July–September), all retrofits reduced energy use, with the largest reduction achieved by cool roof + insulation (4,798 kWh; 20.3%), followed by green roof + insulation (4,927 kWh; 18.2%). Thermal comfort also improved from 1,158 baseline comfort-hours to 1,222 hours in the cool roof + insulation case. The bestperforming combined retrofit reduced average roof surface temperature (31.6°C to 27.2°C) and markedly lowered roof heat balance (4,820 kWh to 356 kWh), driven by substantial Uvalue improvements (2.1 to ~0.40 W/m²·K).

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Jun 25th, 9:00 AM

Sustainable Retrofitting Strategies of Residential Roofs to Meet Minimal Energy Consumption Targets in the UAE

F1-1124

Due to the United Arab Emirates having a hot arid climate, residential buildings experience high cooling demands. A major building element for solar heat gain through buildings are roofs. This study evaluates roof retrofitting strategies for existing low rise residential villas in Al Ain. The aim is to reduce cooling energy consumption, improve indoor thermal comfort, and support compliance with current UAE envelope performance requirements. A case-study villa (Majlis space) was monitored during the peak summer period. Indoor temperature data were recorded using a HOBO device and used to derive an operational HVAC schedule for simulation input. The baseline model was developed in DesignBuilder and calibrated/validated against measured electricity-bill consumption and roof surface temperature checks using a Testo thermal imaging device, following accepted calibration tolerances (e.g., ASHRAE Guideline 14 thresholds). Five retrofit scenarios were assessed: cool roof, green roof, additional insulation, cool roof + insulation, and green roof + insulation. Relative to the baseline cooling demand (6,022 kWh for July–September), all retrofits reduced energy use, with the largest reduction achieved by cool roof + insulation (4,798 kWh; 20.3%), followed by green roof + insulation (4,927 kWh; 18.2%). Thermal comfort also improved from 1,158 baseline comfort-hours to 1,222 hours in the cool roof + insulation case. The bestperforming combined retrofit reduced average roof surface temperature (31.6°C to 27.2°C) and markedly lowered roof heat balance (4,820 kWh to 356 kWh), driven by substantial Uvalue improvements (2.1 to ~0.40 W/m²·K).