Thermal envelope

[Bob-Roraback]

When using Chief Architect and exporting the thermal envelope data for use in Res-check the amount of ceiling area is reduced each time you add an interior wall.

I believe that this is incorrect and that an interior wall should have no bearing on the amount of ceiling area calculated for the thermal envelope. 

I wanted to ask others opinion on this before reporting to tech support.

Proper calculation of the thermal envelope has become much more critical as Connecticut has adopted the 2021 IECC.

Opinions would be appreciated. Thanks, Bob

[DRAWZILLA]

I'm in California where the energy calculations can get crazy and has been for the last 30 years and I agree with your statement. We have our own California energy codes unlike anything else so I really can't use export to Rescheck here. I can use some of the info though and it should be correct.

[KristjanM]

Different energy evaluations require different square footages. Passive house would deduct the interior partition area from the ceiling area. If I'm using Hot 2000 (I'm in Canada), the wall partitions are not deducted. Maybe Chief should allow for options with the calculations.

[Richard_Morrison]

The last time I looked at this fairly recently, the thermal envelope was being calculated based on the interior square footage and wall surface areas, not on the exterior surfaces as required for T24 in California, and even as required for REScheck. So, it was kind of useless. Too bad. With a little more attention, it could be something quite useful. I don't know if it's been fixed since I reported the issues.