The "Historic District" was created with the intent to preserve the historic character of the area and the buildings within it. Special rules in the City's Unified Development Ordinance, along with a special set of Suffolk Historic District Guidelines, govern exterior changes to buildings in the Historic District in order to protect their historical significance and to encourage uses which will lead to their continuance, conservation, and improvement in a manner that preserves the cultural and historic heritage of the City.
Not all buildings in the Historic District are historic. These are called "non-contributing" structures. These include structures that were built less than fifty years ago, or have been significantly altered over time and do not contribute to the historic character of the District.