If you're planning to totally replace the siding on your house -- that is, strip off your present siding and put on new material -- you'll probably need a building permit. If you're just putting a new layer of siding on top of what you have now, you may or may not need a permit, depending on your local building regulations. Minor repairs may not need a permit at all.
Local governments usually require homeowners and contractors to take out building permits for any significant structural work. A permit is a sign that the building department has been notified of the work in progress, will inspect the work to make sure that it conforms to the building code and will approve the work when it's finished. The whole process is designed to ensure that the building is safe and structurally sound, both for the current occupants and for any future owners. Building codes vary across the country, but most are based on the International Building Code, according to the website Bankrate.com. Even codes not directly based on the International Building Code resemble it quite closely.
According to a Bankrate.com review of building codes, you can assume that a permit will be required to completely or substantially remove the siding on your home and replace it with new material. Your building department will want to oversee the work in large part because the materials and workmanship must be able to stand up to the weather in your area. Also, the surface beneath the siding must be properly prepared, so that moisture won't penetrate the walls, causing a mold and rot issue. An inspector will make sure the home is properly sealed.
Covering or Repairing Siding
You'll have to check with your local building department, but you may not have to get a permit if you are simply installing new siding on top of old material. The city of Watertown, N.Y., for example, requires permits for siding or roofing work only if the old material will be stripped off. Also, certain repairs to siding may not be large enough to require a permit. Simply replacing a damaged plank or patching a small hole may pose no danger of disrupting the structural integrity of the house. San Bruno, Calif., for example, says no permit is necessary for repair work involving less than 10 square feet of siding.
If you're merely making cosmetic changes to your siding, such as painting or staining, you probably won't need a building permit. Your community, however, may have property covenants that govern the appearance of homes. Those covenants may limit the colors or materials you can use. You may need to get the OK from a local zoning board, homeowners association or historic district commission to make cosmetic changes.