Actual clay bricks even more so with their imperfect uniformity and consistency. FWIW, at least here, in construction even the thermal insulation clay blocks (

Actual clay bricks even more so with their imperfect uniformity and consistency. FWIW, at least here, in construction even the thermal insulation clay blocks (basically, any wall-construction material made from clay, those red blocks :)) is called "bricks". They are laid exactly like the regular (uniform, filled) bricks, so I would assume that's what's mostly used in construction everywhere even when not going for looks (they are lighter and have better thermal properties).