If you live in a house, you have plumbing. Here are answers to some common questions about home plumbing systems. Q. Do I need a permit to upgrade my plumbing? A. When in doubt, check it out. Even an apparently minor plumbing upgrade like water heater replacement may require a permit, and every locale has its own regulations. There's a good chance they will also specify that you hire only a licensed plumbing contractor. PS: Don't forget to find out what's allowed under the te