There are 3 types of historic districts. The National Park Service designates National Historic Landmark districts that have the highest level of significance in our nation's past. The park service also administers the National Register of Historic Places which designates historic districts significant at local, state or national levels.
Each state has an office which reviews nominations to the National Register and forwards them to the Keeper of the National Register for review and approval. However, the property owner does not require approval for alterations or demolition in these types of districts except in the case of federal ownership or federal licensing, funding or permitting. A locally designated historic district is an area with specific boundaries that has been designated as such by a municipality or a county. Exterior alterations and demolitions in this type of district must be reviewed and approved by the Historic Preservation Commission before a building permit can be issued. However, approved rehabilitation in all of these district are eligible for tax credits.