Excess heat through external walls in the summer time can be eliminated by replacing common cladding sheets by effective thermal insulation panels made of foamed glass. These materials have several interested features as well like: acoustic insulation, water proofing, anti-corrosion, durability and sustainable environmental effects. The current work introduces thermal behavior of foamed glass in reducing the cooling load which has been compared to panels made of plastics that used as common external reflective sheets. The specimens have been processed manually in the labs as well as experimental measurements for man samples of several blowing agent content. The aim is to determine density, porosity, expansion ratio and thermal conductivity coefficient. Images of SEM have been taken for selected samples to recognize the morphology and structure of the foamed glass. The results show that minimum density of the foam was 0.3 g/cm3 at 3% wt of blowing agent, and maximum porosity of the foam was 89%. Also, the thermal conductivity of the foamed glass can be decreased by 90% due to the expansion by 4 times with respect to the solid glass. The cooling load for a typical building that use foam glass panels has expected an energy saving by 41% with respect to the conventional one.