Utility cost savings are calculated based on reduction in total:

Utility cost savings in EDGE are calculated based on reductions in resource consumption sourced from the supply grid, as these are the costs directly borne by the building owner. The EDGE User Guide explains: "Utility cost savings in EDGE are calculated based on the reduction in energy and water consumption from the supply grid, using local tariffs for electricity and water to convert resource savings into financial savings" (EDGE User Guide, Section 2.4: Interpreting EDGE Results). Option D, energy and water consumption from the supply grid, aligns with this definition, focusing on grid-supplied resources. Option A (electricity and water consumption) is partially correct but lacks specificity about the source: "Electricity and water must be grid-supplied to be included in utility cost savings; onsite generation is excluded" (EDGE Methodology Report Version 2.0, Section 4.4: Cost Savings Calculations). Option B (generator fuel and water consumption) is incorrect, as generator fuel is not part of utility cost savings: "Generator fuel costs are not included in utility savings, as EDGE focuses on grid-supplied utilities" (EDGE User Guide, Section 2.4: Interpreting EDGE Results). Option C (building energy and water consumption) is too broad, including onsite sources: "Building consumption includes all sources, but utility savings are grid-specific" (EDGE Methodology Report Version 2.0, Section 4.4: Cost Savings Calculations). Thus, energy and water from the supply grid (Option D) is the correct basis for utility cost savings.