Foundation is the most significant and expensive part in terms of repairing in the house.  It is predominantly composed of concrete as well as post tension cables and rebars.  The periodical expansion contraction of expansive soil will result in foundation movements.  As rule of thumb, if the deflection caused by the movement is over 1.0 to 1.5 inches within 20 feet, the slab will have higher chance to generate cracks on the grade beams, exterior brick veneer walls, corners of doors and windows.  Therefore, measurements of foundation deflection could  provide you the information about the conditions of your foundation.  It 's more scientific to assist you to acquire a property.  

Texas HomeSpection provides you the services of foundation level check using digital leveler to help you aware of existing condition.  You have a record of a starting point, so if cracks are appearing after years down the line, you have measurements to compare.