How to prevent house builders from causing mischief

You have to watch them from the side. My father used to build a house and hired someone to build it. When he was in the sewer, he saw an empty wine bottle placed where the bricks should have been. He was too late and it was covered with cement. When he found out, he scolded the contractor. Some of these workers are evil-minded and deliberately cause harm to the homes of those who live in them in the future.