Instructions / Assembly

4
ENERGY EFFICIENCY
Contributing to Sustainable Buildings
The Evolution of Energy Eciency
We have come a long way with the development of energy-ecient buildings.
1900s
No Insulation
In the 1900s, an exterior
wall would look pretty
much like this: no
insulation.
1940s–1970s
Limited Insulation
As we move into the 1940s and especially during
the energy crisis of the 70s, designers and building
owners start to recognize the need for more
insulation, but it’s still used in a limited amount.
Today's
Integrated Air/Water/Thermal Assembly
In today’s designed assemblies with the emphasis
on energy reduction and sustainable construction,
we now see systems that incorporate air, water,
and thermal eciency all in one assembly.
Paths to Code Compliance
There are three typical paths to compliance:
1. Prescriptive R-Value
• Considers R-value of insulation ONLY
• Compliance is achieved by installing insulation with code-prescribed R-value
2. Performance (overall assembly)
• Considers:
– U-factors: U-value of assembly (above grade)
– C-factors: Thermal conductance (below grade)
– F-factors: Slab edge factors
• Compliance is achieved when assembly meets minimum U-value
• Requires calculations or testing to demonstrate compliance but offers greater exibility in system options
ASHRAE 90.1
2004
ASHRAE 90.1
2007 & 2010
ASHRAE 90.1
2013
IECC
2012 & 2015
ASHRAE 90.1
2016
ASHRAE 90.1
2018
ZONE NON-R R NON-R R NON-R WR NON-R R NON-R R NON-R R
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
Prescriptive R (Minimum) Requirements for Steel-Framed Walls, Above Grade