Numerical study of a residential building energy efficiency improvement: A case study in <scp>T</scp> unisia

Abstract Improvements in residential energy efficiency are a national priority since Tunisia's expanding energy demand is intimately linked to the building sector. This study uses a combined parametric and comparative numerical techniques to examine the impact of important architectural and thermal characteristics. In order to assess the impact of glazing and area ratios, building configuration (detached, semi‐detached and strip configurations), and envelope insulation on energy requirements, simulations were first conducted across three climatic zones in Tunisia, namely ZT1, ZT2 and ZT3. With a 20% glazing rate for south‐oriented dwellings, ZT1 has the lowest yearly energy requirements while ZT2 has the highest energy demands. Heating and cooling loads are significantly impacted by a larger glazing ratio. For instance, cooling load increases from 69 to 91 kWh/m 2 for ZT1, 73 to 95 kWh/m 2 for ZT2 and 99 to 127 kWh/m 2 for ZT3 when the glazing ratio is raised from 10% to 20%. In this instance, under ZT1 climatic conditions, heating and cooling loads will increase by 4% and 24%, respectively. Glazing ratio and area ratio affect cooling considerably more than heating loads when the number of floors increases. Glazing insulation was found to be the most effective method, with a maximum energy savings of 22% compared to 14% for roofs and 3% for walls, in a particular examination of a standard typical R + 1 dwelling with a 240 m 2 area, south‐oriented and with a 20% glazing ratio. Thus, glazing insulation proved to be the most effective way to meet Tunisian energy‐saving requirements in terms of building insulation and area ratio.