Legal Question in Construction Law in California

Yes as long as they are truly unique and separate jobs. It is illegal to divide up a single job to try to fit it into the $500 limit. So, for example, if the contractor is building ten houses and you install doors in each of them for under $500 each, that's legal. But if the contractor is building a ten unit condo building, you and the contractor cannot divide up your work into ten separate projects, one for each unit at under $500, and try to claim that satisfies the rule.