COMcheck is the DOE-approved tool used to demonstrate commercial building energy code compliance, covering envelope, lighting, and in some cases mechanical systems. It's required as part of most commercial permit submittals, but the specific documentation expectations shift depending on the building type, the applicable code (IECC or ASHRAE 90.1, depending on jurisdiction), and the scope of the project — new construction, tenant improvement, or addition.
A complete COMcheck submittal generally covers three areas: envelope compliance (wall, roof, and window/door performance for the building's climate zone), lighting compliance (interior and exterior lighting power density against the applicable maximum), and, where relevant, mechanical system efficiency requirements. Not every project needs all three sections — a tenant improvement with no envelope changes, for example, may only need the lighting section completed.
COMcheck supports both the IECC commercial provisions and ASHRAE 90.1, and which one applies depends on what the local jurisdiction has adopted — some states default to IECC, others reference ASHRAE 90.1 directly, and some allow either as an option. Running the report against the wrong baseline produces a result that doesn't reflect the actual applicable requirement, which is a common and avoidable source of rejected submittals.
COMcheck's lighting and, in some cases, envelope requirements vary by space-use classification — an open office, a warehouse, and a restaurant kitchen carry different lighting power density allowances even within the same building. Misclassifying space use is one of the more common documentation errors, since it can produce a lighting compliance result that doesn't match the actual intended use of the space.
For new construction or additions with new envelope area, the report needs wall, roof, and fenestration U-factor and SHGC data consistent with the architectural plans. As with residential REScheck submittals, this data needs to reflect actual specified materials rather than assumed or typical values, since reviewers routinely cross-check COMcheck figures against the building plans.
Some jurisdictions' COMcheck-adjacent requirements incorporate mechanical system efficiency, and where this applies, the report needs to reflect the actual specified equipment rather than a default assumption. This is particularly relevant on projects where HVAC design (informed by Manual J/S/D-equivalent commercial load calculations) and energy code compliance need to align.
Does every commercial project need all three COMcheck sections — envelope, lighting, and mechanical?
No — the required sections depend on project scope. A tenant improvement with no envelope changes may only need the lighting section; new construction typically needs all applicable sections completed.
How do I know whether IECC or ASHRAE 90.1 applies to my project?
This depends on what the local jurisdiction has adopted as its commercial energy code baseline — confirm with the local building department rather than assuming based on a different project or state.
What's the most common reason a COMcheck lighting section fails?
Misclassified space-use types are a frequent cause, since lighting power density allowances vary significantly by space use and using the wrong classification changes the applicable maximum.
Psychro.Pro prepares COMcheck reports matched to your jurisdiction's specific code baseline and building classification, checked against your actual plans and specs.Learn more.
