Research conducted by the Investigation and Loss Bureau and the Canadian Fire Underwriters Association’ was utilized to develop the original "Standard Schedule for Grading Cities and Towns with Reference to their Fire Defenses". This standard provided the original scientific methodology of measuring public fire defenses and prevalent fire risk.

While the document has been modified over the years to keep pace with the changing character of communities and the advances in public fire protection, it continues to be used today to grade communities. In Canada, the document has evolved into the Classification Standard for Public Fire Protection (CSPFP). This Classification Standard considers the level of fire risk present within the community as compared to the adequacy of water supplies, fire departments, fire service communications, fire safety and prevention codes and other aspects of a community’s fire defenses that have a significant influence on minimizing damage once a fire has occurred.

The Classification Standard for Public Fire Protection incorporates nationally recognized standards such as those published by the National Research Council's Institute for Research in Construction (IRC); National Fire Protection Association, and the American Water Works Association.

Using the Classification Standard, the FUS Certified Fire Protection Specialists assign two classifications to communities with organized fire protection:

  1. Public Fire Protection Classification (PFPCTM), for Commercial Lines Insurers
  2. Dwelling Protection Grade (DPGTM), for Personal Lines Insurers