We have expansive clay soils in North Texas - they expand if there is a lot of rain and shrink if it is dry. Proper grading of the pad prevents the expansion issue and proper foundation watering prevents summer shrinkage. The only reason pier and beam are not as much of a problem is that the utilities are running through the soil under the house and not in concrete. The biggest problem with slab is when you have movements of the slab it can cause leaks - which causes soil expansion. There are parts of Richardson which are not on clay soil. I live in Richardson Heights along Cottonwood Creek and do not have clay soils and though the house is over 45 years old it is standing firm. Richardson is an excellent community, I moved here after 30 years in Dallas and can highly recommend it. It has a responsive government, "walkability", convenience to shopping and lots of services. It has been ranked as a "best place to live" and will continue to enjoy prosperity. UTD which is in Richardson is undergoing major improvements and also will contribute to the overall quality of life. We also chose this community because we could see it is going to be a great place for retirement. You won't regret moving to Richardson. - Sat Jun 27 2009, 09:33