Thermal energy storage (TES) through the use of construction materials incorporating phase change materials (PCMs) can prevent temperature fluctuations and allow energy saving in buildings. With this background, aim of this work is to develop new kind eco-friendly foam concrete (FC) containing lauryl alcohol (LA)-impregnated rice husk ash (RHA) composite PCM. RHA, an agricultural waste product, was used as a carrier material to eliminate the leakage problem of LA. Thus, leakage-free composite PCM (LFCPCM) was first prepared, and then such an RHA-based LFCPCM was integrated with cementitious FC for the first time in this study. The fabricated novel FCs were subjected to detailed examinations in terms of morphological, me-chanical, physical, and TES properties. The DSC outcomes indicated that LFCPCM showed melting phase change at 19.97 degrees C and had a latent heat TES capacity of 99.60 J/g, while the PCM into FC-LFCPCM50 melted at 20.01 degrees C and had a latent heat TES capacity of 16.55 J/g. Solar thermo-regulation performance test results revealed that compared to the reference FC (RFC), the FC-LFCPCM50 wallboard provided about 1.29 degrees C warmer indoor temperature during the cold weather hours, whereas the room center temperature was about 2.8 degrees C lower during the daytime in hot weather conditions. An energy-saving of 14.28 kW h per day is obtained by FC-LFCPCM50 wallboard. The carbon emission equivalences of this energy-saving amount account for 38 kg-CO2, 37.7 kg-CO2, and 6.19 kg-CO2 for coal, natural gas, and electricity, respectively. These re-sults suggest that the fabricated novel FC-LFCPCM50 can be effectively evaluated as green building materials for thermo-regulation and energy saving of buildings.