EnthalixBIM-BEM-BOM
Where the model meets the meter.
Open-source building energy modelling. BIM-BEM-BOM turns a building's IFC model into an EnergyPlus energy model, runs it, and compares the result with what the utility actually billed.
Free, Apache-2.0. Public preview for macOS, Windows and Linux.
Its name is its three parts
One program, carrying a building from the drawing to the meter.
Reads a building's IFC model: its rooms, walls, slabs, roofs, windows and doors. Each assembly is reduced to the single surface EnergyPlus needs, and anything it can't place is reported.
Builds the energy model: site and weather, constructions, schedules, zones and systems. Then it runs EnergyPlus, which you install separately.
Prices the simulated year with your utility's tariff, takes your bills and PV production, and calibrates the model against ASHRAE Guideline 14.
The building's measured operation is compared back against the model.
Practical and honest about what it knows
It reports what it can't place
When the program can't place something from the IFC, it says so, so you can see what the model left out.
It runs before you enter your own code
Public-domain reference values from the DOE/PNNL residential prototype models are included, for each IECC edition from 2006 to 2024.
You bring licensed data from its source
It ships no copyrighted standards tables, weather files or manufacturer data. You get each from its publisher, under its own terms.
Results are estimates
BIM-BEM-BOM produces simulation estimates, not code-compliance documentation. You verify the results you rely on.
Watch on YouTube
See it in action
A narrated walkthrough: the Duplex sample through BIM, every BEM tab and the BOM, then an actual house.
Download the preview
Get the installer for your system from the latest release. The first launch needs one extra step.
| System | Installer | The first time |
|---|---|---|
| macOS (Apple silicon) | .dmg | Right-click the app, then Open |
| Windows (x64 and ARM) | .exe | SmartScreen: More info, then Run anyway |
| Linux (x64) | .AppImage or .deb | An AppImage needs libfuse2 on recent Ubuntu |
You also need EnergyPlus 26.1, installed separately from its own releases. Prefer to build from source? See SETUP.md; a sample building is included.
Who it's for
Researchers, engineers, architects and anyone else interested in practical, honest building energy modelling. Early users are invited to try the preview, report what works and what doesn't, and help shape where it goes next.
Enthalix LLC
BIM-BEM-BOM is offered and maintained by Enthalix LLC. The program is BIM-BEM-BOM; Enthalix is the company.