RESCheck vs COMCheck: A Contractor’s Guide to Energy Compliance Reports
RESCheck shows that a low-rise residential building meets the energy code, while COMCheck does the same for commercial buildings and high-rise residential projects, covering the envelope, lighting and mechanical systems. Both are U.S. Department of Energy compliance tools, and ACDuctDesign.com prepares permit-ready RESCheck and COMCheck reports for contractors and architects in all 50 states, usually within 48 hours.
Energy compliance paperwork is one of the most common reasons a permit stalls. This guide explains what each report covers, which one your project needs, and what information to have ready so it goes through the first time.
What Is RESCheck?
RESCheck is free software from the U.S. Department of Energy Building Energy Codes Program that demonstrates a residential building meets the International Energy Conservation Code or an approved state energy code. Building officials rely on it because it turns a complex code into a clear pass or fail.
RESCheck is designed for low-rise residential work, including:
- Detached one and two family homes
- Townhouses
- Multifamily buildings three stories or less above grade, such as apartments and condominiums
- Additions and alterations to those buildings
Most RESCheck reports use a UA trade-off. The software multiplies the U-factor of each assembly by its area and compares the total to the same building built exactly to code. If your design loses no more heat than the code building, it passes, even if one assembly is below the prescriptive minimum.
The requirements behind that comparison come from the residential provisions of the International Energy Conservation Code, or a state code built on it. Because each jurisdiction adopts its own edition, the same house can pass in one county and need changes in the next. That is why the code edition and climate zone are the first things we confirm on every RESCheck.
RESCheck gives builders flexibility, as long as the whole house still adds up.
What Is COMCheck?
If a client asks what is COMCheck, it is the commercial counterpart to RESCheck. COMCheck is also published by the Department of Energy, and it demonstrates compliance for commercial buildings and residential buildings four stories or more.
Where RESCheck focuses on the envelope, COMCheck can cover three separate parts of a commercial building:
- Envelope: roofs, walls, floors, windows, doors and skylights
- Lighting: interior lighting power and exterior lighting
- Mechanical: HVAC equipment efficiency, controls, economizers and duct insulation
COMCheck can show compliance with the commercial provisions of the IECC or with ASHRAE Standard 90.1, depending on what your jurisdiction allows. On many projects the architect handles the envelope, the electrical engineer handles lighting, and the HVAC contractor or engineer handles the mechanical report.
COMCheck is three compliance reports in one tool, and each trade owns its part.
ENERGY PAPERWORK HOLDING UP YOUR PERMIT?
RESCheck vs COMCheck: Which One Does Your Project Need?
The choice between RESCheck vs COMCheck comes down to the building type and its height, not the size of your company or the size of the job. Here is the quick comparison:
| RESCheck | COMCheck | |
|---|---|---|
| Building types | One and two family homes, townhouses, low-rise multifamily | Commercial buildings and residential four stories or more |
| What it covers | Building envelope (insulation, windows, doors) | Envelope, lighting and mechanical systems |
| Code basis | Residential IECC or approved state code | Commercial IECC or ASHRAE 90.1 |
| Typical preparer | Builder, contractor or energy consultant | Architect, engineer or trade contractor per section |
| Common projects | New homes, additions, apartments up to three stories | Offices, retail, schools, hospitals, mid-rise apartments |
Mixed-use buildings can need both. A three-story building with retail on the ground floor and apartments above, for example, may need COMCheck for the commercial space and a residential compliance path for the units. Your plan reviewer has the final word.
Building type and height decide the form. Everything else is details.
Is RESCheck the Same as a Manual J?
No, and mixing them up is a common reason permits come back. A RESCheck answers “does this building envelope meet the energy code?” A Manual J answers “how much heating and cooling does this building need?”
They use some of the same inputs, which is why they are often ordered together:
- Wall, ceiling and floor insulation values
- Window and door U-factors and areas
- Climate zone for the job site
Many residential permit packages call for both, plus Manual S and Manual D for the HVAC system. Ordering them from one team means the insulation values and window specs match across every report, so the plan reviewer has nothing to question.
RESCheck proves the house is efficient. Manual J proves the system fits the house.
What Does the Energy Code Mean for HVAC Contractors?
Energy compliance is not only the architect’s problem. On both residential and commercial projects, HVAC decisions show up in the paperwork and in the field inspection.
On residential jobs, the energy code typically sets requirements that touch your scope of work directly:
- Duct sealing and, in many climate zones, duct leakage testing
- Duct insulation outside conditioned space
- Equipment sizing based on Manual J and Manual S
- Programmable thermostats and system controls
On commercial jobs, the mechanical section of COMCheck lists the equipment, its rated efficiency and the required controls, such as economizers, setback and demand control ventilation where they apply. The inspector will compare what is installed against that report.
If it is in the energy report, the inspector will look for it on site.
Who Signs a COMCheck or RESCheck Report?
Signature requirements vary by jurisdiction. Both tools generate a compliance certificate with a statement for the person who prepared it to sign, confirming the design matches the report.
Some building departments accept a signature from the contractor or energy consultant who prepared the report. Others, especially on larger commercial projects, require the architect or engineer of record to sign the envelope, lighting or mechanical sections they are responsible for.
Before you submit, check three things with the local plan reviewer: which compliance path they accept, which code edition applies, and who is allowed to sign. Our team can help you confirm those details when you order.
Ask who signs before you submit, not after the correction letter.
How Much Do RESCheck and COMCheck Cost?
Residential and commercial energy compliance reports from our team:
RESCheck
Residential energy compliance
From $199
- Homes, townhouses, low-rise multifamily
- IECC or state code compliance
- Up to 2 minor revisions
COMCheck
Commercial energy compliance
From $299
- Envelope, lighting or mechanical
- IECC or ASHRAE 90.1 path
- Accepted by building departments
What Information Do You Need to Order a RESCheck or COMCheck?
Complete information is the single biggest factor in turnaround time. Have these ready when you order:
- Architectural plans with floor plans, elevations and wall sections
- The job site address so we can confirm the climate zone and code edition
- Insulation types and R-values for walls, ceilings, floors and slabs
- Window and door schedules with U-factors and SHGC values
- For COMCheck mechanical: equipment schedules, efficiencies and controls
- For COMCheck lighting: fixture schedules and wattages
If a value is missing from the plans, we will flag it before we run the report rather than guess. That keeps your submission accurate and avoids a correction notice after the fact.
Send it complete and it comes back fast.
Why Do Energy Compliance Reports Get Rejected?
Most rejections are avoidable. These are the issues plan reviewers flag most often:
- Wrong code edition selected for the jurisdiction
- Wrong climate zone for the job site
- Insulation or window values that do not match the plans
- Using RESCheck on a building that needs COMCheck, or the reverse
- Missing signatures or incomplete mechanical sections
ACDuctDesign.com checks the code edition, climate zone and building type before preparing every report, as part of our Contractor-Dedicated Service. That front-end check is what keeps your permit moving.
The right form, the right code edition, the right numbers. That is a permit that sails through.
Frequently Asked Questions
What is the difference between RESCheck and COMCheck?
What is COMCheck used for?
COMCheck is U.S. Department of Energy software used to show that commercial buildings meet the commercial provisions of the IECC or ASHRAE Standard 90.1 for envelope, lighting and mechanical systems.
Do apartment buildings need RESCheck or COMCheck?
Is a RESCheck the same as a Manual J?
How fast can I get a RESCheck or COMCheck?
Standard turnaround is 48 hours from receipt of all required information (see our turnaround terms). Rush service is available for an additional fee by calling 800-810-3280.
