Abstract Building energy demand for heating and cooling has a complicated relationship with different environmental conditions surrounding the building sector. Many projects aiming to improve thermal performance in existing buildings in Jordan suggest that roof insulation will improve thermal performance. In this study we try to prove that minimizing building infiltration is more effective and provides a lower cost solution in low-income houses in Jordan. This work introduces a comparative analysis of the infiltration rate and insulation techniques applied to standalone low-income houses in Jordan to identify the energy efficiency of those techniques for different climate zones in the country. A building simulation presenting the common building configuration used in was developed to test the effectiveness of various insulation scenarios (Roof, Wall, Roof and wall together) and infiltration rate scenarios. The results show that in different climates the reduction of infiltration to half (0.75 air changes per hour (ACH)) shows a similar potential to reduce energy demand as 10 or 12.5 cm roof or wall insulation. Also, the reduction of infiltration rate to a low level (0.25 ACH) can decrease energy demand more effectively than 12.5 cm insulation in the roof or walls.