When in comparison with natural stones, even though interlocks are cheap they are not a good option for the environment. It increases the heat and prevents the water from penetrating into the soil. But in some cases, they are quite what you need. We have made interlocking possible from the front yards of residential buildings to petrol bunks, roads, godowns and worked on our famous beypore bay with our 80 mm thick M-40, M-35 etc graded pavements