Slater & Gordon is representing several homeowners in the north-western and western suburbs whose newly built houses are cracking and twisting.

Lawyer Robert Aurrichio blames a particular type of concrete slab foundation, known as a "waffle slab", claiming it's risky to use in the volatile soil conditions in the west.

"We've spoken to a number of experts who believe that [the waffle slab] needs to be designed with adequate drainage to cope with the variable nature of the soil in the western suburbs," he said.

The waffle slab design reinforces concrete using a steel grid with polysyrene cubes placed between the lining. It maximises efficient use of concrete and requires less material than conventional flat slab designs.

Mr Aurrichio said houses sitting atop waffle slabs in the western suburbs, where the clay layer is deeper underground, seemed to be "heaving" with soil movements as moisture levels moved up and down with this year's heavy rain.

Archicentre general manager David Hallett said waffle slabs had been widely used for more than a decade across Melbourne's western growth areas due to the high volume of new housing estates.

"In suburbs like Caroline Springs, areas around Burnside, Tarneit, Werribee and Melton, the simple fact is that there's been thousands of these buildings built over the last decade and typically more and more have been with waffle slabs," he said.

But Mr Hallett disputed Slater & Gordon's claim that building cracking was related to a particular design of concrete slab foundation.

He said foundations for any new building needed to be designed to suit the soil conditions of the site, as determined by soil tests, irrespective of whether they used waffle or flat slabs.

Slater & Gordon client Noel Spooner says the foundations of his two-year-old home are breaking.