If you've submitted a commercial building permit anywhere in the U.S., you've probably run into a requirement for a "COMcheck report." It's one of the most common documents building departments ask for, and it exists for a specific reason: to prove, on paper, that a commercial building's envelope, lighting, and mechanical systems meet the energy code before construction even starts.
COMcheck is a free software tool developed by the U.S. Department of Energy's Building Energy Codes Program. It's the standard method for demonstrating that a commercial building — or a commercial addition, alteration, or tenant fit-out — complies with the energy code provisions adopted in a given jurisdiction, most commonly a version of the IECC's commercial provisions or ASHRAE 90.1.
The tool covers three main compliance areas: building envelope (walls, roof, windows, insulation), interior and exterior lighting power allowances, and, in some versions, mechanical system requirements. A project can be compliant on the envelope but still need to demonstrate lighting compliance separately — COMcheck handles each as its own module.
Any commercial project subject to the commercial energy code provisions in its jurisdiction typically needs one, including new commercial construction, commercial additions, and many interior renovations or tenant improvements that touch the building envelope, lighting, or mechanical systems. High-rise residential buildings (generally four stories and above) are also usually classified under commercial energy code provisions rather than residential ones, meaning they need COMcheck rather than REScheck.
Requirements vary somewhat by jurisdiction and by which energy code edition and compliance path (prescriptive, performance, or an alternative like ASHRAE 90.1) has been adopted locally.
For the envelope path, COMcheck compares the actual proposed building assemblies — wall R-values, roof insulation, window U-factors and SHGC — against the code-required minimums (or a trade-off calculation that allows some assemblies to underperform if others overperform enough to compensate). For lighting, it compares proposed lighting power density against allowed watts per square foot, either using the whole-building method or the space-by-space method depending on project needs.
The output is a compliance certificate and detailed report showing exactly what was checked, what the code requires, and how the project meets or exceeds those requirements — the document plan reviewers actually look for when processing a commercial mechanical or building permit.
It's worth understanding that "COMcheck compliance" isn't a single pass/fail number. A project can use the envelope trade-off approach (where a larger-than-typical window area is offset by better wall insulation elsewhere) while using a straightforward prescriptive approach for lighting. Getting all three checks aligned with what's actually going to be built — not just what looks good on paper — is where COMcheck reports most often go wrong, since discrepancies between the submitted report and actual construction show up during inspection.
COMcheck has historically been available as both a desktop application and a web-based tool (COMcheck-Web). The Department of Energy has been rolling out an updated COMcheck-Web platform intended to eventually serve as the single home for current and future national and state energy code implementations, replacing the older legacy web version, which had fallen behind on supporting the most recent code editions. Which version — and which code edition — is appropriate depends entirely on what's been adopted in the specific jurisdiction the project is permitted in, so confirming the correct code year before starting a report matters more than it might seem.
A COMcheck report isn't just a box to check for permitting — it reflects real decisions about how much a building will cost to heat, cool, and light over its operating life. Getting the underlying inputs right (actual specified assemblies and lighting fixtures, not generic placeholders) means the report reflects the building that actually gets built, not just a document that satisfies a reviewer on day one.
Is COMcheck the same as an energy audit?
No. COMcheck is a code-compliance demonstration tool used during design and permitting, not a post-occupancy energy audit or performance verification of an existing building.
Does every commercial project need a COMcheck report?
Most do, though requirements depend on the specific jurisdiction, project scope, and which compliance path (prescriptive, performance, ASHRAE 90.1) is being used. Some jurisdictions accept alternative energy modeling software instead.
Can COMcheck be used for high-rise residential buildings?Yes — buildings above the height/story threshold that separates residential from commercial energy code provisions (commonly four stories) typically fall under commercial requirements and use COMcheck rather than REScheck.
What happens if a project doesn't meet prescriptive requirements?The envelope trade-off method within COMcheck often allows compliance by improving performance in one area to offset a shortfall in another, without needing to switch to full energy modeling.
Psychro.Pro handles COMcheck compliance reporting alongside Manual J, S, and D — one workflow covering both HVAC sizing and commercial energy code documentation. Learn more.
