Instructions / Assembly

7
OVERVIEW
Drivers of Continuous Insulation
Striving for Continuous Efciency
Choosing the right insulation and placing it in the right location is becoming one of the most important decisions in design, construction,
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stringent energy codes and performance expectations, the use of continuous insulation on the exterior of the building is critical.
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envelope via a continuous path, such as through wood studs, or more commonly, highly conductive steel framing members. Thermal
bridging dramatically affects entire wall R-value. For instance, a steel stud wall assembly with batt insulation will lose 50% of its R-value
through thermal bridging.
In addition to the management of thermal bridging, having the insulation outboard of the structure has other advantages. Air and
vapor barriers can be installed as a single material adjacent to wall sheathing, allowing for continuity of the barriers. Placing the
insulation outboard of the support structure will also move the dew point closer to the outer face of the wall, reducing the potential for
condensation within the wall.
ASHRAE 90.1 remains the primary reference standard for energy codes adopted by states and local jurisdictions to regulate the design
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version of ASHRAE 90.1. The matrices shown below illustrate a summary of the code requirements active today for both non-residential
and residential construction and the current building envelope requirements.
Prescriptive R (Minimum) Requirements for Steel-Framed Walls, Above Grade
ASHRAE 90.1
2004
ASHRAE 90.1
2007 & 2010
ASHRAE 90.1
2013
IECC
2012 & 2015
ASHRAE 90.1
2016
IECC
2018
ZONE
NON-
RESIDENTIAL RESIDENTIAL
NON-
RESIDENTIAL RESIDENTIAL
NON-
RESIDENTIAL RESIDENTIAL
NON-
RESIDENTIAL RESIDENTIAL
NON-
RESIDENTIAL RESIDENTIAL
NON-
RESIDENTIAL RESIDENTIAL
0 N/A N/A N/A N/A N/A N/A N/A N/A 13 13 13 13
1 13 13 13 13 13 13 13 + 5.0 13 + 5.0 13 13 13 13
2 13 13 13 13 + 7.5 13 + 3.8 13 + 7.5 13 + 5.0 13 + 7.5 13 + 3.8 13 + 7.5 13 + 3.8 13 + 7.5
3 13 13 + 3.8 13 + 3.8 13 + 7.5 13 + 5.0 13 + 7.5 13 + 7.5 13 + 7.5 13 + 5 13 + 7.5 13 + 5 13 + 7.5
4 13 13 + 7.5 13 + 7.5 13 + 7.5 13 + 7.5 13 + 7.5 13 + 7.5 13 + 7.5 13 + 7.5 13 + 7.5 13 + 7.5 13 + 7.5
5 13 + 3.8 13 + 7.5 13 + 7.5 13 + 7.5 13 + 10.0 13 + 10.0 13 + 7.5 13 + 7.5 13 + 10 13 + 10 13 + 10 13 + 10
6 13 + 3.8 13 + 7.5 13 + 7.5 13 + 7.5 13 + 12.5 13 + 12.5 13 + 7.5 13 + 7.5 13 + 12.5 13 + 12.5 13 + 12.5 13 + 12.5
7 13 + 7.5 13 + 7.5 13 + 7.5 13 + 15.6 13 + 12.5 13 + 15.6 13 + 7.5 13 + 15.6 13 + 12.5 13 + 15.6 13 + 12.5 13 + 15.6
8 13 + 7.5 13 + 10 13 + 7.5 13 + 18.8 13 + 18.8 13 + 18.8 13 + 7.5 13 + 17.5 13 + 18.8 13 + 18.8 13 + 18.8 13 + 18.8
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Current Building Envelope Requirements, ASHRAE 90.1 2019
NON-RESIDENTIAL RESIDENTIAL
ZONE ASSEMBLY MAX INSULATION MIN. R-VALUE ASSEMBLY MAX INSULATION MIN. R-VALUE
0 U 0.124 13 U 0.124 13
1 U 0.124 13 U 0.124 13
2 U 0.084 13 + 3.8 c.i. U 0.064 13 + 7.5 c.i.
3 U 0.077 13 + 5.0 c.i. U 0.064 13 + 7.5 c.i.
4 U 0.064 13 + 7.5 c.i. U 0.064 13 + 7.5 c.i.
5 U 0.055 13 + 10 c.i. U 0.055 13 + 10 c.i.
6 U 0.049 13 + 12.5 c.i. U 0.049 13 + 12.5 c.i.
7 U 0.049 13 + 12.5 c.i. U 0.042 13 + 15.6 c.i.
8 U 0.037 13 + 18.8 c.i. U 0.037 13 + 18.8 c.i.