A foam concrete has constituents that include a cement, a sand, a coarse aggregate having a density in a range of 1400-1600 kg/m3, a water, and a foam solution. The foam solution includes a foaming agent and a foaming water. The foam concrete has a compressive strength of at least 20 MPa, a thermal conductivity of less than 0.40 W/mK and a maximum dry weight of 2000 kg/m3.