Also referred to as no-fines or porous concrete, permeable concrete uses the same raw materials as conventional concrete except that the fine aggregate proportion of the mix is removed entirely. Our mix design process using single sized coarse aggregate of 10, 14 or 20mm nominal size with strict control of the cement and water contents results in reduced particle packing potential with a stable void content that is highly porous. Permeable concrete can be used as a lightweight infill or overlay material and with thermal conductivity values of approximately half that of conventional concrete, permeable concrete gives excellent insulation characteristics.