The building code has evolved to protect a home’s occupants as well as the community, but first, you need to determine whether a permit is required. In cases of simple interior cosmetic changes, such as repainting and installing interior trim or carpet, a permit will not be required. For remodels that add square footage to your home or make structural modifications, a permit will definitely be needed. Other projects, such as those involving cosmetic changes to your exterior or landscape, may or may not require a permit.
When in doubt, take a trip down to your local building jurisdiction and ask, or seek help from a reputable professional in your area.