These comparisons give an indication whether resource consumption is increasing or declining or whether there are any abnormal changes. Avoided costs can be identified relative to a baseline year or other similar period. Graphically portraying monthly or annual consumption and cost is one of the easiest ways to identify trends. Most programs provide options for adjusting consumption and cost to account for changes in weather. To allow for valid comparisons between facilities that are not identical, performance indices are often created.
Resource costs normalized by building square footage.
Cost divided by consumption for a particular resource. Cost of a particular resource relative to total resource cost. A common example is electricity demand cost as a percentage of total electricity cost. Building area is a common divisor for these indices for buildings. Other appropriate divisors such as number of employees, residents, or students could be used.