Building Energy Modeling (BEM)
Building Energy Modeling (BEM) is the practice of using computer-based simulation software to perform a detailed analysis of a building’s energy use and energy-using systems. An energy modeler will input data to create the building model, including weather, building orientation, geometry, constructions, occupant schedules, and energy-using equipment.
Results are typically reported for annual performance and include the space cooling and heating loads, daylighting impacts, equipment energy use, resource consumption, energy costs, and other performance-related parameters. BEM provides a number of benefits to both new construction and retrofit projects. The expense of modeling services usually represents a marginal incremental cost to the project, yet can influence significant reductions in annual energy costs.
In general, there are three ways that BEM can provide value to a project and benefit the owner:
- Reduced first costs
- Reduced operating costs
- Improved occupant satisfaction
Incorporating BEM within building efficiency projects has become increasingly common as owners recognize its value for improving existing building performance or supporting the design of high-performance buildings. Applications are categorized by their general modeling purpose; modeling to compare, modeling to comply or modeling to predict.