NSLPS, in consultation with other heritage building organization and other lighthouse societies, has adapted the following heritage buildings principles for development and preservation work at lighthouse sites. These principles are derived from internationally recognized heritage building principles, originally based on the Venice Charter for the Conservation and Restoration of Monuments and Sites.
1. Respect For Historic Material: Minimal intervention shall be the guiding principle. To maintain the historical content of the resource. wherever possible conserve, repair and reuse building materials and finishes. Where necessary, repair with like materials.
2. Respect For The Building's History: Lighthouse sites have evolved over time. Do not arbitrarily remove a building or feature of a building solely to restore to a single period of time or commercial theme.
3. Reversibility Of Alterations: If alterations are unavoidable, they should be made in a way that allows the building to return to its original state. This conserves earlier building design and technique. Any changes should be fully documented.
4. Legibility Of Additions: Additions to a historic building should be distinguishable from the original. While the addition should harmonize and not overwhelm the original, they should not blur the distinction between old and new.
5. Respect For The Original Location: Buildings should only be moved if there is no other means to save them. Site is an integral component of a building. Change in site diminishes heritage value.
6. Respect For Site: The value of a site is not just the building but the setting which reflects its history. This applies not to just great works of architecture but also modest and humble sites which have acquired importance through time and community association. The scale and style of any new buildings should complement the site.
7. Ruins & Archaeological Features: Disturbance of soil during construction must be monitored to ensure significant historical or archaeological information is not destroyed.
8. Respect For Documentary Evidence: Conservation and restoration work shall be based on historic documentation such as historic photographs, plans and physical evidence, never on conjecture.
In addition to these broad principles, the society has also adopted more detailed guidelines for certain areas: