If you’re a do-it-yourselfer and are doing anything significant to your home, make sure you check the local building codes. They are always changing and usually to make something safer, not necessarily better and rarely easier. This is particularly true if you live in an old house. The older the house, the more changes are likely to be required.
Let’s start with electrical codes. The evolution of electrical wiring from early “nob and tube” is one significant item. Fuse boxes almost always have to be replaced with circuit breakers. The location and number of electrical outlets is a code item. If your house is an old one you can be sure you don’t have enough outlets. Moreover, they have to be grounded. Kitchen and bathrooms require GFCI (ground fault circuit interrupter), sometimes called GFI outlets, which have a breaker built right into the outlet which will pop if there’s a short circuit or overload. Remember, water is an electrical conductor.
Plumbing is another code item. Lead pipes can be a problem and they are not a cinch as the cliché says. Asbestos-associated with the heating system will usually have to be removed if you are making any major changes to the system like replacing the burner. A word about asbestos: it should be removed professionally if you don’t know how to do it safely. Dry asbestos flakes and becomes dangerous dust.
If you are doing anything to exterior walls, consider the code for insulation requirements, which will invariably require increasing it or in some cases putting it in where it never existed. I strongly suggest you get a building permit for the work you are going to do and be sure you have it inspected to be sure you confirm. The cost for the permit is usually nominal. It’s not the cost of the permit that bothers DIYers, it’s the cost of bringing things up to code and the bother of dealing with the inspection process. Some towns are easy to deal with. Others are impossible. But if you do work without a permit, you are in danger of being forced to undo your work if you’re caught. It’s not usually worth the risk. If you are doing major work, ripping it out can be very expensive not to say aggravating. A word to the wise…