One-story detached tool and storage sheds, playhouses, and similar uses that are less than fourteen feet tall and one hundred twenty square feet in floor space are free from building permit requirements. Freestanding outside walls and fences no taller than six feet; accessory buildings such as carports, breezeways, and garages attached to a dwelling; and swimming pools less than five feet deep do not require a permit. Nonconforming structures may be restored or modified over time without further approval from the city. For example, an existing one-story shed that is fourteen feet by one hundred twenty feet can be enlarged to fifteen feet by one hundred twenty feet without requiring a new permit. The city's code administrator has the power to grant exceptions from building permit requirements. The code administrator may also deny or revoke any permit he/she finds was issued in violation of applicable laws or ordinances or otherwise contrary to good public policy. A notice of intention to appeal a decision of the code administrator must be filed within ten days of receipt of the decision. The city council can override the code administrator's decision by a vote of four out of seven members. Building permits cost between $150 and $200. The amount depends on the size of the project. Larger projects typically require more than one permit, with separate fees charged for each one.