Minor structures, such as birdhouses, yard light poles, birdbaths, doghouses (housing dogs which are licensed as the personal pets of the residents of the property), tree houses, noncommercial fuel storage tanks and pumps, clothesline poles, lawn ornaments, flagpoles, mailboxes, garbage containers, ice fishing shanties and school bus waiting shelters. Nonhabitable structures of not more than 100 square feet, which can be easily moved, and meet applicable setback requirements, are also exempt.