N1102.2.2

Section N1102.2.2 is titled 'Ceilings without attic spaces' and covers requirements for energy efficiency. The allowance for a limitation of the R-value in roof/ceiling assemblies, clarification that the insulation shall be extended to the outside edge of the top plate, an area limitation for this allowance, and a clarification that this allowance is not intended to apply to the U-factor and total UA alternative approaches is established. The purpose of this section is to allow for practical construction methods.

The model shows an unvented roof section (commonly referred to as a cathedral ceiling), which is 500 square feet total insulated area. If the insulation is spray foam type and the R-value is 30 for the full depth of the rafters, is this installation compliant?