The use of advanced framing with insulation sheathing is another concept used to reduce the amount of materials in residential construction. The layout of the sheathing boards over the area of the wall framing should be done to minimize the amount of cutting of the material and construction waste created.

This will impact the effective thermal resistance of the wall assembly as well. Standard residential construction will end up with a framing fraction for the wall assemblies of around 23% of the wall area. With advanced framing this fraction can be reduced down to approximately 16% and sometimes even less. If we reexamine the techniques for calculating the effective R-value of the assembly as used in the Thermal Resistance section we obtain the following results.

The effective R-value of the following assembly with a 16% framing fraction is:

R(cavity) = 1/[(0.84/19)+(0.16/5.83)]

R(cavity) = 13.96

R(total) = 0.17+0.62+13.96+0.45+0.68

R(total) = 20.26

The same effective R-value with a 23% framing fraction yielded a total R-value of 18.80. This represents a 7.8% increase in thermal resistance for the entire assembly.