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Codes, Standards, Rating Systems, and the Roofing Industry

May 15, 2012

Based on the number and type
of questions received at the
RCI office, there appears to
be some confusion regarding
“insulation above-deck” re –
quirements in the various
standards and codes. Questions asked are,
“What are the current requirements?” and
“When can I expect to see changes?” “What
is driving these changes?” and “How can I
explain the benefits to
clients?” Below is a brief summary
of what the current
standards are and what we
can expect in the future.
I will begin by explaining
the difference among standards,
codes, and rating systems.
Standards are consensus-
based documents, often
referred to in codes and ratings,
and are considered the
current and minimum bestpractice
policy. They may or
may not be adopted as
mandatory. Codes are a man –
datory consensus and reflect
a minimum standard of care
of building design and construction.
Ratings intentionally
exceed the minimum
codes to demonstrate leadership
and commitment to the profession and
usually earn a label of distinction. LEED® is
a good example of this.
When it comes to the roofing industry,
many of the questions asked are related to
the requirements for roofing insulation. The
current ASHRAE 90.1-2010 has prescriptive
requirement revisions based on the
individual climate zones. See Table 1 and
the climate zone map on this page.
These increased
thermal requirements
and the re –
quirements of cool
roofs in climate
zones 1, 2, and 3 in
ASHRAE 90.1-2010
are just two ways to help meet the 30%
entire building energy savings goal established
by the Department of Energy (DOE).
38 • I N T E R FA C E F E B R U A RY 2012
Climate zone map.
How do things stand anow? ASHRAE
Standard 90.1 is continually being updated
through the addendum process. There has
been an addendum proposed that would
increase insulation levels, but it has not yet
been approved. After committee review, the
addendum will again go through the public
review process. For the latest public review
drafts and addenda to ASHRAE Standard
90.1, please monitor the ASHRAE standards
Web page at
According to Stephen V. Skalko, chair of
the standard 90.1 committee, ASHRAE
90.1-2013 aims to have an SSPC goal of
50% improvement of regulated loads and a
40% improvement of all loads relative to
ASHRAE 90.1-2004, so building envelope
design will continue to become more energy-
restrictive. Increased roof insulation Rvalues
are almost certain to be included.
More information can be found at:
w w w . e n e r g y c o d e s . g o v / e v e n t s /
189.1-2009, Standard for the Design of
High-Performance Green Buildings Except
Low-Rise Residential Buildings is the jurisdictional
compliance option for commercial
and high-performance buildings of the
International Green Construction Code
(IgCC). It follows ANSI standards in model
code language. It establishes minimum
requirements for high-performing green
buildings and covers setting design, construction,
and plans for operations. Like
ASHRAE 90.1, it can be applied to all buildings
except low-rise residential. It can be
applied to new buildings and their systems,
new portions of buildings and their systems,
and new
systems in
e x i s t i n g
It covers
the same
topics as
L E E D ®
and in –
cludes comm
i s s i o n i n g ,
operations, and
maintenance. Un like LEED®, the standard
is not a de sign guide or a rating sys tem.
Meet ing standard 189.1 criteria does not
guarantee that one will meet the minimum
requirements for LEED®, but LEED® is compliant
with both Stan dards 189.1 and 90.1.
F E B R U A RY 2012 I N T E R FA C E • 3 9
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Climate R-value U-Value R-value U-Value
Zone 1 15ci .063 15ci .063
Zone 2 15ci .063 20ci .048
Zone 3 15ci .063 20ci .048
Zone 4 15ci .063 20ci .048
Zone 5 15ci .063 20ci .048
Zone 6 15ci .063 20ci .048
Zone 7 15ci .063 20ci .048
Zone 8 20ci .048 20ci .048
Table 1
Table 2
*These numbers are unchanged since the ASHRAE 90.1-2007 version
ci = continuous insulation
ASHRAE 90.1-2004 ASHRAE 90.1-2010*
(Previous) (Current; same values as 2007)
Nonresidential/Residential Nonresidential/Residential
Climate R-value U-Value R-value U-Value R-value U-Value
Zone 1 15ci .063 20ci .048 25ci .039
Zone 2 20ci .048 25ci .039 25ci .039
Zone 3 20ci .048 25ci .039 25ci .039
Zone 4 20ci .048 30ci .032 30ci .032
Zone 5 20ci .048 30ci .032 30ci .032
Zone 6 20ci .048 30ci .032 30ci .032
Zone 7 20ci .048 35ci .028 35ci .028
Zone 8 20ci .048 35ci .028 35ci .028
ASHRAE 90.1-2010 ASHRAE 189.1-2009
(Baseline) (Baseline)
Nonresidential/Residential Nonresidential Residential
While there are mandatory requirements for
all projects, ASHRAE 189.1 also offers a
choice between prescriptive and performance
paths to meet compliance. Pre –
liminary figures from the DOE through the
National Renewable Energy Laboratory
have estimated that the minimum prescriptive
recommendations in the standard
result in an average site energy savings of
27% over Standard 90.1-2007. On October
27, 2010, Katherine Hammack, assistant
secretary of the Army for installations,
energy, and the environment (IE&E), issued
a policy memorandum that incorporates
Standard 189.1-2009. See Table 2.
What is the future for standard 189.1?
It is tough to know what the future will hold
with this standard, but it is like standard
90.1 in that it will be under continuous
maintenance with addenda and public
reviews. Currently, there is a standard
189.3P, titled “Design, Construction and
Operation of Sustainable High Performance
Health Care Facilities,” in development. It is
designed to specifically address the healthcare
And how do these standards fit into
code? The ICC International Energy Con –
servation Code (IECC) is the minimum energy
code for commercial and residential
buildings and references ASHRAE 90.1 as
the equivalent compliance path for commercial
buildings. It uses outcome-based performance
and covers design, construction,
commissioning, occupancy, and use. It is
generally in track with 90.1 but with more
stringent envelope provisions, including
commissioning requirements for accreditation.
It addresses the building envelope,
HVAC, and solar hot-water equipment,
lighting, and power. Unlike ASHRAE 90.1-
2010, it does not address plug-and-process
The current 2009 IECC adopted
ASHRAE 90.1-2007 by reference when window-
to-wall ratio (WWR) is over 40% or
skylight-to-roof ratio (SRR) is over 3%.
There are a few differences between the
2009 IECC and ASHRAE 90.1-2007. One is
that space considered semiheated in
ASHRAE 90.1 is considered heated in IECC.
This accounts for more rigorous overall
thermal envelope provisions. Another is
that ASHRAE 90.1 considers some vertical
glazing skylights; and, therefore, it has less
thermal requirements than if considered
vertical fenestrations by 2009 IECC. This
impacts the building air-leakage testing.
Another item of significance is that 2009
IECC does not have provisions for highalbedo
roofs in certain climate zones. It is
also important to note that IECC 2012 prescriptive
R-values have been increased over
2009. See Table 3.
What is the future of IECC? The U.S.
DOE submitted 56 code change proposals
for the International Code Council’s (ICC)
Code Development Cycle that will produce
the 2012 I-codes. The 2012 code has an
estimated energy savings of 25% over the
IECC 2006/ASHRAE 90.1-2007. There are
additional changes being considered that
may increase this by 5%. There will be more
rigorous U-factors for fenestrations and a
cap on vertical fenestrations. There are
minimum daylighting requirements and a
vestibule required for all building
entrances. The DOE is interested in keeping
Chapter 5 of the 2012 IECC aligned with
ANSI/ASHRAE/IESNA Stan dard 90.1-
2010. There is also a movement toward netzero
measurement and Europe’s Energy
Performance of Building Directives (EPBD)
measurement. The future focus is on
increasing energy efficiency by 50% in minimum
codes and more in green/sustainable
codes and standards. The adoption of
ASHRAE 189.1-09 and ICC are currently in
The IgCC is an overlay code that works
with or in tandem with administrative re –
quire ments of other I-codes. It is not de –
signed to compete with other standards and
rating systems. ASHRAE is included as an
extension of IgCC. For example, the
ASHRAE/USGBC/IES Standard 189.1 is
included as a jurisdictional compliance
40 • I N T E R FA C E F E B R U A RY 2012
Climate R-value U-Value R-value U-Value
Zone 1 15ci .063 20ci .048
Zone 2 20ci .048 20ci .048
Zone 3 20ci .048 20ci .048
Zone 4 20ci .048 25ci .039
Zone 5 20ci .048 25ci .039
Zone 6 20ci .048 30ci .032
Zone 7 20ci .048 35ci .028
Zone 8 20ci .048 35ci .028
ASHRAE 90.1-2010 IECC 2012
(Baseline) (Baseline)
Nonresidential/Residential Nonresidential/Residential
Table 3
option. IgCC codifies the minimum tenets of
sustainability and acts as a driving force for
sustainable practice. It also addresses the
Architecture 2030 challenge, which has the
following targets:
• All new buildings, developments,
and major renovations be designed
to meet a fossil-fuel, greenhouse-gasemitting,
energy- consumption performance
standard of 50% of the
regional (or country) average for that
building type.
• At a minimum, an area of existing
building equal to that of new construction
be renovated annually to
meet a fossil-fuel, GHG-emitting,
energy-consumption performance
standard of 50% of the regional (or
country) average for that building
• The fossil fuel reduction standard
for all new buildings be increased to:
— 60% in 2010
— 70% in 2015
— 80% in 2020
— 90% in 2025
— Carbon-neutral by 2030 (zero
fossil-fuel, GHG-emitting energy
to operate).
This may be accomplished through
innovative design strategies, application of
renewable technologies, and/or the purchase
(maximum of 20%) of renewable
The IgCC is customizable to the geopolitical
and economic climates and codes of
the locality and has minimum and
advanced levels of performance and prescriptive
options. Jurisdictions indicate 0
to 14 as the minimum number of project
electives with which one must comply to a
total of 60 electives, and the owner
/designer chooses specific electives for compliance.
The IgCC addresses building performance
in terms of total net annual energy
use, peak demands, and carbon emissions.
It is tied to energy performance and
has a minimum of a 15% energy-saving
requirement over 2012 IECC. The provisions
in the new 2012 IgCC were completed
during the Final Action Hearing on October
31, 2011, in Phoenix, AZ. This new 2012
code will be available in the spring of 2012.
To see which standards and codes are
currently impacting your jurisdiction, the
U.S. DOE has an excellent spreadsheet at
Rebecca Cunningham, LEED AP, RA, is the director of educational
services for RCI, Inc. She is a multiple-awardwinning
architect registered in North Carolina and Florida,
with 18 years of experience in commercial architecture and
civil and structural engineering. One of her projects recently
won the Exemplary Project Award at the 2011 Fifth Annual
Green Building Leadership Awards Program in Columbia, SC.
Rebecca Cunningham, LEED AP, RA
Architecture 2030 challenge graphic.
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F E B R U A RY 2012 I N T E R FA C E • 4 1