The thermal properties of buildings' envelope play a significant role in determining energy consumption and thermal comfort within a building. This is the direct effect of the heat gain through the building's envelope on temperature distribution over its interiors. The thermal properties of a building material are not constant due to the variation of the material's components and its manufacturing from a place to the other. This work aims to extract the thermal properties of the commonly used building materials across Egypt using a lab-scale designed device. The experiment's device and settings have been validated. The results of this work will facilitate and enhance the performance of thermal simulation of building interiors within the Egyptian context through accurate specification of the local building materials' thermal properties. Commonly utilized building materials across Egypt are examined such as light brick, cement brick, hollow clay brick, ceramic, mosaic tiles, and beech wood. It is noticed that there is difference in the thermal properties' values of some tested materials when compared to the Egyptian code, while they are found to be agreed with some other studies. This difference or agreement can be referred to the component of the material and its manufacturing process.