Builders reports I've seen here on clay soils suggest a flat out removal policy within 3m of the house and within 3m only little shrubs and plants/flowers.
Adelaide has some of the worst clay soils around. I remember patching the house was a bi-annual ritual.
Here's an interesting current read.
http://www.theage.com.au/news/nation...105023577.html According to the research, South Australia was the worst affected state, with 48 per cent of surveyed houses affected by cracking.
In Tasmania, 45 per cent of homes were affected, 38 per cent in Victoria, 36 per cent in NSW and WA, and 18 per cent in Queensland. http://www.domain.com.au/Public/Arti...0cracking%20up
However prevention is better than cure ... so plant smart in the beginning.
And as mentioned above by boa subsidence upon removal needs to be considered also.