First, that law sounds insane! It scares me. This type of law could destroy the construction trade. I understand the idea of a warranty. It should be a workmanship warranty. It should cover thing the builder has control over. This is like saying that if there is a crack in your drywall the entire wall has to be replaced. Also, a homeowner should not be able to determine if something is a structural problem. A professional engineer should have to make that decision. In the extreme case, after nine years almost every timber in house could have a small check and the owner could demand the house be replaced. This is nuts! Sorry for the ranting.