Frequently Asked Questions (FAQs)

Topics - building envelope - basement - walls - Residential
After selecting a basement wall type, a basement wall illustration will appear with input boxes for the basement wall height, depth below grade, and depth of insulation. The illustration helps identify the dimensions being requested. You may enter...
Topics - building envelope - windows - windows - fenestration - Commercial - sprandel systems - u-factor
Fenestration is considered anything that transmits light, however, COMcheck cannot calculate fenestration without having a wall associated with it. In this case the wall is entirely fenestration therefore, the square footage would be the same for...
Topics - building envelope - walls - Residential
Walls that do not fit into any of the preset categories in REScheck (preset categories come directly from the applicable code currently selected in the Code menu) may be entered under the "Other" wall type. When "Other" is chosen as the wall type,...
Topics - addition - alteration - building envelope - Residential
REScheck determines compliance for additions in the same manner as new construction. When entering an addition, only the new portions of the building need to be shown in the software. REScheck will perform trade-offs between envelope assemblies...
Topics - building envelope - Commercial - software
If multiple users are putting information into COMcheck, each may fill out the appropriate section independently. However, all sections of the building must show compliance to the same code or standard (e.g., cannot show envelope compliance to IECC...
Topics - building envelope - Commercial
COMcheck computes an envelope index that is a reflection of the difference between a 'design' building energy performance factor (EPF) and a 'code' or budget building EPF.  The total building load (made up of cooling, heating, lighting, and...
Topics - building envelope - Commercial
Louvers are best treated as un-insulated portions of the wall. You can add them as a separate wall type (for example, if they are metal, metal building would probably be most appropriate) with no insulation but a wall area. COMcheck will do the...
Topics - building envelope - Commercial - 40% WWR glazing limitations
The Scope and Application sections of the 2009 IECC address use of ASHRAE 90.1 (2007) as an alternative.  See below for the text.  It is appropriate to use ASHRAE 90.1 as an alternative when your building exceeds 40% glazing, although it does not...
Topics - building envelope - walls - windows - fenestration - windows - glazing - Commercial - calculating above-grade wall area
COMcheck implements the calculation based on the definition of above and below-grade walls in the applicable code.  The calculation for percentage of glazing in ASHRAE Standard 90.1 and the IECC are different as the IECC only looks at above grade...