Tips for effective energy analysis of commercial building designs

Many methods and tools are available to perform an energy analysis. Energy modeling is among the most robust. No matter which method is used, it’s important to consider all fuel sources and uses of the building, as well as its intended operating patterns.

The goal is not to model the perfect building, but to model a realistic building. The "perfect building” scenario could receive a high 1 – 100 ENERGY STAR score, but may not accurately reflect real-life activity and energy use of the building. It’s better for the design team to use a realistic simulation to gain confidence that the design can achieve Designed to Earn the ENERGY STAR recognition and other goals.

To ensure accuracy, make sure your energy analysis accounts for:

  • Total annual energy use from all fuel sources (electricity, natural gas, steam, chilled water, wood, propane, etc.)
  • Regulated load assumptions, such as equipment and systems
  • Non-regulated load assumptions, such as plug loads and process loads
  • Building size
  • Number of workers
  • Hours of operation
  • Location
  • HVAC design and operating schedules
  • Lighting systems and operating schedules
  • Equipment efficiency data from the manufacturer
  • Right-sizing systems
  • Passive design strategies

Note: Not all modeling programs calculate additional energy uses required for domestic hot water, exterior lighting, elevators, and similar systems, but these elements should also be included in the simulation model.