Rescheck is a residential home construction energy audit software and report developed by the Pacific Northwest National Laboratory and Department of Energy.

Comcheck is a commercial construction energy audit software and report developed by the Pacific Northwest National Laboratory and Department of Energy.

Despite their similarities they also have many differences. Join us in this special edition of the Reschexpert blog as we put Rescheck and Comcheck head to head. We look at the differences in the types of construction they can be used for, the energy codes they work with, and how you might use them on your own project.

Ladies and gentleman, it's Rescheck vs Comcheck. Ding Ding Ding.

Written by Jobe Leonard of Jobe enjoys all things related to Rescheck reporting and the study of home energy audit softwares like Rescheck, Comcheck, and Manual J.

Rescheck vs Comcheck

Today on the Reschexpert blog we feature an epic battle of two of the top energy auditing softwares of all time. We love to look at and work with different types of energy auditing software and increase our knowledge, and the skills of our readers. Today we look at the softwares Rescheck and Comcheck and compare each of them.

In this corner we have Rescheck software, here is what you need to know:

Rescheck is a energy audit software for residential structures both one and two family. It can also be used for multifamily buildings as long as they are less than three stories above grade.

There are two softwares used to create Reschecks. Rescheck Web and Rescheck Desktop.

Free Rescheck Web Is Online (Printable PDF)

Rescheck uses tradeoffs to calculate a pass or fail score.

Rescheck currently includes 15 different Energy Codes:

IECC 2009, IECC 2012, IECC 2015, IECC 2018, IECC 2021, Florida 2017, Massachusetts 2020, Denver 2019, 2017 Washington DC, 2016 NYECC, 2020 NYECC, 2020 NYStretch – IECC 2018, Puerto Rico, Utah 2012, and Vermont 2020.

Rescheck typically generates a 10-13 page report in PDF format that includes 3 different sections. Calculations, checklist, and compliance certificate.

Rescheck Example

Rescheck is the most commonly accepted form of home energy audit accepted at building departments across the United States that have adopted residential IECC energy codes.

A Rescheck costs $79 and can be prepared in 4-6 hours.

Rescheck Form

In the other corner we have Comcheck software. Here is what you need to know:

Comcheck is a energy audit software for commercial structures of all types and purposes.  It can also be used for multifamily buildings that are more than 3 stories high. We also see some building departments requiring the Comcheck for mutlifamily structures that are less than 3 stories even though Rescheck is suitable. This is because sometimes on the same property you will have a 4 story mutlifamily building next to a 2 story multifamily building. To ease inspection we feel that some building departments would like to inspect these structures using 2 Comcheck reports. Instead of using a Rescheck on one structure and a Comcheck on the structure across the parking lot.

There are 2 different softwares used to calculate Comchecks. Comcheck Web and Comcheck Desktop.

How To Log In To Comcheck Web (2024)

Comcheck uses tradeoffs to calculate a pass or fail score.

Comcheck can currently calculate efficiency using 27 different Energy Codes:


90.1 2007 Standard, 90.1 2010 Standard, 90.1 2013 Standard, 90.1 2016 Standard, 90.1 2019 Standard, IECC 2009, IECC 2012, IECC 2015, IECC 2018, IECC 2021, Ontario, 2017 DC Energy Code, Puerto Rico 2011, Vermont 2020, Florida 2020, Boulder 2020, 2019 Denver IECC 2018, Denver 90.1 2016, 2020 Massachusetts Energy Code, 2016 NYECC, 2020 NYECC, 2020 NYECC modified ASHRAE 90.1 2016, 2020 NYECC Modeling Envelope Backstop, 2020 NYECCC, 2020 NYStretch – IECC 2018, 2020 NY Stretch 90.1 2016 Standard, 2020 NY Stretch 90.1 2016 Modeling Envelope Backstop.

Comcheck typically generates a 12-15 page report in PDF format that includes 5 different sections. Envelope, Checklist, Interior Lighting, Exterior Lighting, and Mechanical.

Comcheck Web Projection Factor Error

Comcheck is the most commonly used commericial energy audit software in the United States and even includes one Canada specific code, Ontario.

A Comcheck starts at $149 and typically takes 10-12 hours to complete.

2023 Comcheck Service Price List

Now that you see each software head to head you realize that even though we have placed Rescheck and Comcheck against each other it is really like a monster truck versus a race car. They each have different purposes. Which one would win would depend on what type of project you are working on. Comcheck is a much larger software with more sections and codes. Rescheck is much more commonly used because by default the US sees more residential home starts each month than they do commercial structures. Both are amazing softwares that are created by the Pacific Northwest National Laboratory and the Department of Energy.

Both softwares, Rescheck Web and Comcheck Web both undergo routine maintenance.  This maintenance has 3 recurring characteristics:

  1.  The software updates for Rescheck Web and Comcheck Web are typically pre-announced 7-10 days in advance through the use of a red banner withing the Rescheck and Comcheck interface.
  2. The updates are relatively short.  Each update typically lasts between 18-24 hours.  During the maintenance time period it can be difficult to create Reschecks and Comchecks as the software will have glitches.
  3. The updates are periodic.  Typically, every 4-6 months you will see Rescheck and Comcheck undergoing an update.  So these bi annual energy audit software updates are not occurring at a frequency we would deem a nuisance.  

Here are some examples of the latest Rescheck Web Maintenance update, and the lastest Comcheck Web Maintenance update.

During the most recent update a new version of Comcheck Web was announced lovingly called “New Comcheck.”  You can learn more about New Comcheck on this Reschexpert blog post.

At we can help you with either type of report. If you need to get started on a Comcheck or Rescheck. Just let us know which one your building department has requested and email us PDF plans, jobsite address, and square footage to and we will get you taken care of.

Review Date
Reviewed Item
Rescheck versus Comcheck
Author Rating
Software Name
Rescheck Online Comcheck Online
Software Name
Windows, MAC, Linux, Android, Mozilla, Chrome, Explorer, Safari,
Software Category
Residential Energy Code Compliance, Commercial Energy Code Compliance