ADOPTING PASSIVHAUS PRINCIPLES IN RESIDENTIAL BUILDINGS IN THE EXTREMELY HOT-DRY CLIMATE OF SAUDI ARABIA

Abstract

The high demand for cooling in Saudi Arabia due to the severe hot climate contributes to high energy consumption per capita, which is three times higher than the global average. More than 50% of the energy consumption in Saudi Arabia comes from the residential sector. This study evaluates energy-efficient measures that can be employed in Saudi Arabia to reduce the heavy consumption of energy in the residential sector. The study focused on the city of Makkah, which experiences a hot climate throughout the year. And assessed the extent to which this city strictly meets energy efficiency standards, specifically the German Passivhaus concept, which evaluates greenhouse gas (GHG) emissions and energy consumption in residential buildings. Through this concept, this study focused on improving the building envelope and utilising high-performance windows in two residential buildings, which is a popular type of residential in Makkah. The first building was compliant with the Saudi Building Code (SBC), and the other was not compliant with SBC (non-SBC). The assessment was conducted by DesignBuilder, a dynamic thermal simulation software, to compare the two buildings' energy performance with the Passivhaus requirements standards in current and future (2050 and 2080) climate scenarios. Further studies were carried out using the OneClick LCA software to evaluate the two villas’ lifecycles and the impact of applying the Passivhaus standard principles on carbon emissions. The study compared the actual thermal performance for both buildings with the simulated models employing two validation techniques. The first, conducted when the buildings were free-running, involved assessing the hourly temperature calibrations by comparing the indoor and outdoor temperatures derived from the DesignBuilder model with the real temperature values recorded by data loggers. The second is calculating and comparing the simulated energy consumption for both buildings with their utility bills over three months. The accuracy of the simulations was enhanced by generating the weather data files for the current and future scenarios (2050s and 2080s) using the RCP 4.5 GHG emission scenario for Makkah City from Meteonorm, a climate generator software. The results of this investigation indicated that Passivhaus principles have an encouraging environmental impact. They show that a building envelope that meets Passivhaus Standard target can reduce significant cooling demand by 57% in SBC-compliant and 60% in non-SBC buildings. In addition, the Passivhaus models were around 20% more effective in addressing climate change challenges under future climate scenarios than the SBC and non-SBC models. Lastly, comprehensive lifecycle carbon analyses of the case studies demonstrated that following the Passivhaus standard principles significantly reduced cumulative carbon emissions over the estimated 40-year lifespan of both models. This finding underlines the potential of Passivhaus standard to substantially contribute to reducing carbon emissions, with savings of more than 50%.