Key performance metrics for energy and facility engineers (part II)

Composite image of a person touching a tablet with charts and graphs overlaid above the screen

Last month, we discussed the importance of energy and facility engineers monitoring the performance of the buildings and systems under their control. We focused on establishing an energy baseline and using benchmarking tools and energy performance indicators to compare performance against peer facilities. However, the majority of facility managers need to monitor other metrics as well.

Tracking a facility’s maintenance costs using a set of key performance metrics is important. Key metrics include:

  • mean time between failures
  • mean time to repair
  • overall equipment effectiveness
  • cost of asset maintenance
  • cost to replace versus cost to repair
  • unplanned maintenance percentage
  • work order resolution time

There are a variety of computerized maintenance management systems that can perform these assessments and share the results through various reports.

Monitoring indoor environmental quality (IEQ) and occupant comfort is important for managers because it relates to personnel health and productivity. While indoor climate (temperature and humidity) is typically the primary focus, other factors must be considered, including ventilation (carbon dioxide levels), airflow rates, pollutants (biological, volatile organic compounds, dust and other particulate matter), noise and light levels.

Besides tracking these parameters, other metrics used to monitor IEQ and comfort include tracking the number of absences for illness per employee each year per square foot and the number of comfort complaints per occupant each year per square foot. Managers can also track the percentage of time an occupied facility is within temperature and humidity setpoints. Finally, various companies have developed productivity metrics based on their specific requirements.

Many companies have created sustainability management plans and are identifying, assessing, and working to reduce their greenhouse gas (GHG) emissions, including carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride.

The GHG Protocol corporate standard classifies a company’s greenhouse gas emissions in three “scopes.” Scope 1 accounts for all direct emissions from owned or controlled sources, including all assets such as facilities, equipment and vehicles. Scope 2 accounts for indirect emissions from the generation of purchased energy. Scope 3, which is the hardest to calculate, accounts for all indirect emissions (except those in Scope 2) that occur throughout the value chain of the reporting company. This includes upstream and downstream emissions. The Environmental Protection Agency’s benchmarking tool I mentioned last month, Energy Star Portfolio Manager, offers the Building Emissions Calculator, which allows users to create estimates for location- and market-based GHG emissions.

The global facility and energy management services’ markets are projected to have rapid growth over the coming decade, driven by the need to manage energy consumption, optimize renewable energy sources, decrease corporations’ carbon footprint and grow investments in energy-efficient smart buildings.

The Energy Management Association offers a course on the performance metrics described above and in last month’s blog article and is developing an expanded course that will include the calculations and evaluations of these metrics.

Hanson has a number of dedicated engineers and energy management professionals with experience in developing metrics and analyzing same for clients and their facilities. For further information, contact Bob Knoedler at or Bill Bradford at

Posted on April 18, 2023