• Hi Amber,

Choice 1 is incorrect because the 1" of polystyrene rigid in the cavity is not enough to meet the code, which says that R-5 c.i. (continuous insul) is needed in the metal walls of a commercial building.  1" at R4.5 = R4.5.

Choice 3 is the correct one!

Hope this helps!

Rebekka O'Melia, Registered Architect, NCARB, B. Arch, M. Ed, Step UP,  Step UP ARE 5.0 Courses

• Hi Rebekka thanks for your help. Passed PDD! On to my last exam PPD!

• You're welcome!  And congrats on passing Amber, that's great!!  You're almost done!

Rebekka O'Melia, Registered Architect, NCARB, B. Arch, M. Ed, Step UP,  Step UP ARE 5.0 Courses

• I'm confused by this question as well.

The chart requires an R-value for 'Mass' walls (I am assuming this is the brick maybe I am wrong) of R7.6.

I had been calculating the 1.5 inches of polystyrene rigid as insulation for that wall portion, which is 6.75 and less than the mass wall in the chart requires.

Or is it that the brick is ignored and the 1.5 inches of polystyrene rigid is just extra above and beyond the steel frame wall with batts?

• Brick veneer is not a mass wall.  It’s a veneer.  If it were 2-3 courses of brick or solid concrete, then that’s a mass wall.

Rebekka O'Melia, Registered Architect, NCARB, B. Arch, M. Ed, Step UP,  Step UP ARE 5.0 Courses