Key Takeaways

  • 7,631 projects reported in 2021 were energy modeled, including 1,056 by fuel sources.  
  • 59.7% of whole building projects reported in 2021 by count included at least one energy model.
  • 2 billion gross square feet were energy modeled in 2021, representing 66.6% of the gross square footage reported by whole buildings.
  • Whole building projects reported with an energy model in 2021 achieved an average pEUI reduction of 52.3% while whole building projects reported without a model achieved an average pEUI reduction of 46.4%.

Model building energy use at multiple design stages

Measuring predicted energy use intensity (pEUI) in buildings is a vital step in designing high-performance buildings, but it’s not a one-and-done procedure.

In fact, the best way to get the full value of energy modeling is to start very early with a baseline and target pEUI, as well as a “simple box” or “shoebox” model, to compare options and help optimize orientation and massing. Comparing options should continue as design progresses.

Architects can use early energy modeling tools themselves, or they can work closely with modeling professionals. Either way, architects need to take the lead on energy modeling, driving the process and ensuring that design changes made by everyone on the team respond to the models’ findings. For projects reported with energy models in 2021, 18.8% were modeled by a member of the architecture team, 51.7% by a design engineer, and 20.6% by an energy modeling consultant, and 7.7% by other parties.

Too often,  energy modeling is done after design is over just to prove code compliance or to achieve a building certification credit. This misses all the opportunities to compare features to inform daylighting, develop building envelope specifications, and implement other passive design strategies.

Modeling is the only way firms can reliably estimate how their projects will perform so they can make changes before the project is built, and it allows firms to help their clients predict and reduce future utility costs. Together with cost estimating, it’s also the best way to identify the most cost-effective ways of achieving high performance—thus using clients’ money responsibly to arrive at the right solutions. In 2021, more than 7,600 whole building projects reported at least one energy model, equivalent to 66.6% of gross square footage reported. Most projects’ energy models were conducted in the construction administration phase.

In the past, modeled projects in the DDx have consistently had greater pEUI reductions than non-modeled projects. This occurred in 2021, with modeled projects demonstrating a 6% greater reduction of pEUI than non-modeled projects.

And for projects pursuing net zero energy—276 for this reporting year, and that number should skyrocket as we approach 2030—modeling is an imperative part of the process, allowing the project team to predict how much renewable energy will be needed.

Image credits

Maine Coast Waldorf School

Chuck Choi

The last three reporting years and percentages of whole building GSF with energy models.


Modeled whole building projects had an average pEUI reduction of 52.3%, while non-modeled were an average of 46.4%.


Majority (58%) of the whole building GSF was modeled by design engineers.


Majority of whole-building GSF utilized the 'Other' or 'Not Modeled' category for energy modeling tool.