A Builder in Michigan was using Rescheck to demonstrate 2009 IECC energy code compliance as part of the permit application process. I was consulted, because the home could not pass code through ResCheck with open-cell foam in wall cavities and foundation walls, high efficiency furnace, attic with flash coat of foam, covered with R-50 blown cellulose.
I was told by the person completing the ResCheck model, that we must now use the r-value rating of fiberglass for the cavity insulation, no matter what the rated R-value of the insulation used in the cavity.
Has anyone else heard of this illogical standard?
I have used RemRate to determine code compliance and have not used this standard. Are there other issues like this I should be aware of?
My reading of the code indicates that the code official can determine what is an acceptable energy modeling software.
Any other suggestions for easily documenting code compliance for this builder? I'd love to do a HERS rating for every house, but I can't believe that's necessary here. Rescheck does not account for infiltration. This contractor builds a tight house, I'm sure that would help it pass through the performance path.
And yes, if r-5 continuous insulation was applied to the exterior, it would pass. I prefer that method of construction too, but that is not my question today.