Concrete blocks are large blocks usually with two large internal hollow interiors. They are usually cheaper to buy per square meter of wall, and being a large product, they are cheaper to lay.

Concrete blocks will need to be laid on a concrete foundation and which will require firm soil and or shale underneath. The exterior surface of the concrete blocks should be made waterproof with a cement based paint or coating. The interior can be finished with cement render and painted or solely painted. Once the walls are built, they are almost finished apart from the painting. This is a less expensive construction technique than double brick construction.

Concrete blocks can be used for retaining walls. Once the wall has been built, steel reinforcing bars specified by a structural engineer is positioned, and concrete is poured to fill the the large internal hollow interiors.