Air infiltration, the exchange of outdoor air with indoor air through leaks in the building envelope, is a crucial factor that influences the energy performance of buildings. This study presents a comprehensive assessment of air infiltration in social housing units in Egypt using blower door tests and estimates its impact on energy consumption using simulation modelling. A field study was conducted on four social housing units, consisting of two conventional and two green building models. Blower door tests were performed on each unit following ISO 9972. The assessments made in four residential structures show an average air permeability of 19.52 m3/h m2, the traditional units’ average air change rates at 50 Pa (ACH) were measured to be 9.22 h−1. The green model, in contrast, displayed average air change rates of 7.34 h−1 and 13.94 m3/h m2 for air permeability. By just improving the quality of the window frame, green building models are 20% more airtight than conventional ones in terms of ACH and 28% less in air permeability. Simulation modelling was conducted to understand the impact of air infiltration on energy consumption. The measured air infiltration rates were used in the simulation models, along with climate data, thermal properties of the building envelope, and HVAC system efficiency. The simulations demonstrate that in terms of cooling loads, heating loads, overall energy consumption, and energy use intensity (EUI), the total annual electricity use in the green models was reduced by 2.3% compared to the traditional models. These findings highlight the importance of reducing air infiltration to improve energy efficiency in social housing units. In conclusion, this study underscores the significance of addressing air infiltration in social housing. It recommends the adoption of green building practices to reduce air infiltration, leading to improved energy performance and greater sustainability in social housing units.