Normal red bricks are just a rectangular piece of block made of compressed clay. The clay brick is affected by the mineral content and chemical nature of the raw materials, the temperature at which the brick is burnt, as well as the environment in the kiln.
The hollow block is machine made and consistent in its finish and unaffected by weather conditions unlike the red bricks in our country. The hollow block uses technology which fits two bricks in a locking shape; it is like two pieces of a jigsaw puzzle as a result of which they are highly uniform in shape. It also decreases the use of mortar due to its mechanism as well as the construction cost and time and labor hours.