Modeling the envelope

1. The table in Appendix A cover uninsulated assemblies. The whole idea is to account for the whole assembly U-value including the framing. The same values apply outside the US.

2. In the Baseline you can just model the U-value if your software allows you to do so without entering layers.

At the top of table A3.1A (for masonry walls), for R-insulation, there are three options:

* Assembly U-factors for 8 in. Normal Weight 145 lb/ft3 Solid Concrete Walls
* Assembly U-factors for 8 in. Medium Weight 115 lb/ft3 Solid Concrete Block Walls
* Assembly U-factors for 8 in. Medium Weight 115 lb/ft3 Solid Concrete Block Walls: Partially Grouted

So, my question is: what if I have masonry walls covered with concrete that in total is 9.8 in. ?

Please advice.

Extrapolate or conservatively use the lower value produced by the 8 inch masonry or look up the R-value of 1.8 inches of concrete and add it to your Appendix A total or if the wall is just solid concrete just use a point calculation. The difference in any case should be very minimal. Appendix A is intended to account for framing effects, especially steel conduction, in whole construction assemblies.

Thanks Marcus, I think a good idea may be to get the R-values for the bricks and then add the R-value of the concrete at both sides. I mean, get the U-value by calculus instead of tables A.

If you don't use Appendix A make sure to explain to the reviewer how you derived the U-values modeled. Appendix A is a readily accepted methodology. Your calculus would potentially require additional justification.