The existing residential building stock in UAE: Energy efficiency and retrofitting opportunities

-The building industry accounts for the largest percentage of the total energy use and carbon emissions globally. The per capita electricity consumption in the United Arab Emirates (UAE) is one of the highest in the world, of which the built environment accounts for 70% of energy consumption, as compared to the global average of 40%, mainly due to the need for cooling. The residential sector as the dominant infrastructure component in a city carries a heavy energy usage for cooling to mitigate the local extreme hot climate. A condition further exacerbated by the lack of an energy building code until 2010. Hence, this paper explores the opportunities for building energy efficiency retrofitting in an existing representative residential unit in Al Ain city, UAE. First, thermal leakage through the building envelope was audited through infrared thermography to identify the impact of time, workmanship and construction quality on the building thermal efficiency. Then, building envelope upgrades were tested through energy simulation. The objective is to identify energy upgrade opportunities and prioritize retrofitting solutions. Residential units in two housing complexes built over a decade apart were selected for testing in Al Ain city, UAE. Thermal testing at critical points including corner wall junctions, roof junction, windows frames and external glazed sliding doors was carried out. The auditing highlighted some common thermal behavior and variances, including a critical need for building envelope insulation as expected. Newer units, however, had significant thermal anomalies around building’s junctions, indicating that building’s age may not be the main referent for a retrofitting priority. Workmanship and construction quality may be a more critical factor. The older unit that showed less thermal leakage compared to the newer unit has been selected for energy simulation to test the building envelope upgrades. The results indicate potential annual electricity savings up to 48.6% through building envelope insulation leading to a 50% reduction of CO2 emissions.