Energy Modeling
Software-based simulation that predicts a building's energy use before it's built, based on its design, [[concept-building-envelope|envelope]] performance, mechanical system efficiency, orientation, and local climate data, used to compare design options and verify a project is on track to meet an energy or certification target.
Why it matters
Without a model, comparing two design options' actual energy impact is mostly guesswork: a more expensive window package might or might not be worth its cost depending on how much it actually reduces total building energy use. Energy modeling turns that comparison into a number the design team can weigh against cost.
On a real project
A design team runs an energy model comparing two HVAC system options and finds the more expensive system pays back its added cost in reduced energy use well within the owner's target timeframe, a conclusion the team couldn't have reached by comparing the two systems' specifications alone.
Who this matters most to
A Sustainability/LEED Consultant uses energy modeling throughout design to track progress against a net zero or certification energy target. An HVAC Technician's as-installed work is ultimately what the model's mechanical efficiency assumptions depend on holding true.
Where this goes wrong
A project relies on an early energy model's projections without updating the model as later design changes affect the assumptions it was built on. The final building's actual performance diverges significantly from what was projected, since the model never reflected some of the value-engineering substitutions made along the way.