Foam concrete is a light-weight concrete. It has high flowability, porosity, fire resistance, airborne sound insulation, good heat insulation, and a desirable compressive strength. The goal of this study is to produce thermal insulation foamed concrete cladding using cement, fly ash, and rice straw. Rice straw and fly ash were used to improve the thermal properties of foamed concrete. The present study analyses the thermal and strength properties of foam concrete. Numerical study to investigate the thermal insulation capacity using COMSOL software is also done. The w/s ratio of 0.55, fly ash cement ratio of 1:1 is fixed for all the specimens. The result shows that the mix with 1% rice straw (by weight of cement), 20% foam volume, is found to be optimum in terms of strength, thermal conductivity. © 2020 Elsevier Ltd. All rights reserved.