Using basal stabilisation of a structural stone fill reduces the volume of stone required in construction, and consequently reduces the volume of excavation and imported fill. This reduces construction costs and CO2 emissions which is more sustainable and environmentally friendly. The stabilisation provides a long lasting effect, but it is often the temporary loading during construction (before the surfacing) that determines the critical design condition. The following “rules of thumb” provide a guide for comparison of the options available. For a more detailed assessment, ABG provides a complementary design calculation service based on the soil conditions (e.g. CBR), stone grading and traffic conditions.