Mixed-use buildings — ground-floor retail with residential units above, for example — don't fit neatly into a single energy compliance tool, and figuring out whether a project needs REScheck, COMcheck, or a combination of both is one of the more common points of confusion for contractors and developers working on this building type.
REScheck applies to residential construction, and COMcheck applies to commercial construction — but a mixed-use building contains both under one roof, and the compliance framework typically follows the use of each portion of the building rather than treating the structure as a single uniform building type. This means the residential units and the commercial space generally need separate compliance evaluations, even though they're part of the same physical structure.
The residential units within a mixed-use building — apartments or condos above ground-floor commercial space, for instance — are typically evaluated using REScheck (or the applicable state-specific residential tool, like Title 24 or R405) against the residential energy code provisions, covering envelope and, where applicable, mechanical systems specific to those units.
The commercial or retail portions of the same building are typically evaluated separately using COMcheck (or the applicable state commercial standard), covering that space's envelope, lighting, and mechanical requirements independent of the residential compliance calculation happening elsewhere in the structure.
Some building components — shared mechanical systems, common area lighting, or building envelope elements that serve both residential and commercial space — require careful scoping to determine which compliance framework applies. This is often one of the more technically complex aspects of mixed-use compliance, since a shared component doesn't cleanly belong to either the residential or commercial evaluation.
Because mixed-use projects typically require both REScheck and COMcheck documentation prepared in parallel, coordinating the two — ensuring shared systems aren't double-counted or omitted entirely, and that the overall submittal clearly shows which compliance framework covers which portion of the building — matters for a clean plan review. A submittal that doesn't clearly delineate this boundary is more likely to generate reviewer questions.
Does every mixed-use building need both REScheck and COMcheck?
In most cases, yes — if the building includes both residential and commercial conditioned space, each portion generally needs its own compliance documentation under the applicable framework.
How are shared mechanical systems handled in mixed-use compliance?
This needs to be scoped carefully and can vary by jurisdiction — some shared systems are evaluated under whichever standard covers the majority of the served space, while others require a specific allocation approach. Confirming with the local jurisdiction is important.
Is there a simpler compliance option for small mixed-use buildings?
Some smaller mixed-use projects may qualify for simplified compliance approaches depending on the jurisdiction and building size, but this should be confirmed locally rather than assumed.
Psychro.Pro prepares coordinated REScheck and COMcheck documentation for mixed-use projects, scoped correctly across residential and commercial portions of your building.Learn more.
