This　paper　presents　an　experimental　study　on　the　effects　of　using　agricultural　waste　coconut　shells　for　producing　synthesized　biomass　recycled　aggregate　(SBRA)　and　replacing　natural　aggregate　(NA)　with　its　equivalent　amount　on　the　durability,　thermal　conductivity,　carbon　dioxide　emissions,　and　economics　of　concrete.　Test　results　show　that　the　3-day　and　28-day　compressive　strength　of　concrete　with　the　addition　of　SBRA　-　Class　III　reached　93%　and　88%　of　natural　aggregate　concrete　(NAC),　respectively.　In　addition,　using　SBRA　can　effectively　reduce　the　thermal　conductivity　of　concrete,　which　shows　great　potential　for　building　energy　conservation.　Compared　with　NA,　the　use　of　SBRA　can　reduce　CO2　emissions　and　the　cost　of　concrete　by　2%　and　5.9–7%,　respectively.　And　the　compressive　strength　-　CO2　emission　efficiency　and　compressive　strength　-　cost　efficiency　are　comparable　to　NA.　©　2022　Elsevier　Ltd