The Standards and Guidelines are based on universally recognized conservation principles inspired by international heritage conservation charters.

A. Understanding

A comprehensive understanding of a historic place is acquired through documentary and oral research, as well as physical investigation. Such research and analysis will lead to the identification of the heritage value of the historic place and the character-defining elements that embody its heritage value.

• Heritage value: the aesthetic, historic, scientific, cultural, social or spiritual importance or significance for past, present or future generations.
• Character-defining elements: the materials, forms, location, spatial configurations, uses and cultural associations or meanings that contribute to the heritage value of a historic place, and which must be retained in order to preserve its heritage value.

For historic places included on the Canadian Register of Historic Places, their heritage value and character-defining elements are set out in a Statement of Significance.

B. Planning

Planning is a process that connects comprehensive understanding of a place with interventions that will respect its heritage value. In planning, it is important to focus on the long term and maintain a strong awareness of the large picture. Planning must take into account all factors affecting the future of a historic place, including the owner's needs, resources and external constraints.

C. Using

The use of a historic place may be part of its heritage value, in which case, it must be maintained. Otherwise, a new use compatible with the defined heritage value should be considered. Uses that are economically, socially or symbolically viable are the best guarantee of the long-term survival of a historic place.

D. Intervening

Intervention at a historic place must respect its heritage value and character-defining elements. It is always better to preserve than to repair, and better to repair than replace. Any additions must respect the spirit and substance of the existing. This "minimal intervention" approach is the foundation of good conservation practice.