Sink-hole suburbs?

A number of new greater Melbourne Western and Northern fringe suburbs are reported as potential 'sink-hole' disaster areas due to a combination of extremely volatile clay strata in the soil and alleged use of time and money saving foundation technology totally inappropriate for that type of land condition. Many new home buyers have reported cracking of foundations, floors, walls and ceilings within two years of occupancy. In response, experts have sounded an alarm that some of the volatile areas may be prone to develop vast sink-holes perhaps leading to catastrophic damage to buildings ill-equipped to combat severe earth movement.

It just so happens that my home is situated in what was once well-known as being a part of the very same volatile north-western region of Melbourne. I only became aware of the fact while the house was being built during the last half of 1972. Whilst on a visit to the construction site, I queried why the wall foundations were being excavated so deeply. The answer was 'to comply with building regulations dealing with extreme soil volatility'. The rear trenches went to a depth of 10 feet to ensure that the foundations would rest on a natural gravel shelf below the seams of clay. It seems that soil condition regulations were not only clear on regional land problems... but, also acted upon diligently by building contractors 40+ years ago! Why not now?

The resultant stress and heart-ache being experienced by new home owners in these affected areas must be excruciating.