The background and procedures embodied in the recent Texas Board for professional Engineers Advisory Report on Residential Foundations Appendix A represents extensive geotechnical research and practice relating to unsaturated clay soils. The effect of local soil properties and environmental factors on new design and forensic analysis should be a part of geotechnical, structural and foundation engineer's tool kits. These procedures, as well as the effects of barriers, drainage and vegetation on foundation support conditions are discussed and illustrated. Procedures for determining soil support parameters (Em) and (Ym) values and examples of designes will be presented