Before your building been settled, you should check as much (you know) as you can to see if those things are completed as per contract. One of my friends found out few downlights are not connected properly till the downlights were broken, and it was too late (already out of 90 days maintainence period). He has to pay the big price to fix them by his electrocian.

A tip: even some faulty service been found beyond 90 days, you can still contact your builder. Some good builders are willing to keep their reputation, and would fix their faulty services. Never give up trying!