In the United States, building plans must be done by an architect, engineer and draftsman who are all trained and tested by the government before they are granted a license to work.

Plans must be submitted well in advance so that trained experts can study the plans, including calculating concrete compaction, load-bearing capacity of beams, etc. The plans must equal or exceeded acceptable standards.

Each step of the construction process is inspected and "signed off" by trained government inspectors, many of whom were once licensed contractors themselves.

If all the proper rules are followed, it is very unlikely that the contractor can be held legally liable if the building fails. Should it be proven that he bribed inspectors or cheated on key structural components, that is a different story.