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[Federal Register Volume 76, Number 138 (Tuesday, July 19, 2011)]
[Notices]
[Pages 42688-42701]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-18080]

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DEPARTMENT OF ENERGY

[Docket No. EERE-2010-BT-DET-0030]
RIN 1904-AC17

Updating State Residential Building Energy Efficiency Codes

AGENCY: Department of Energy, Office of Energy Efficiency and Renewable 
Energy.

ACTION: Notice of final determination.

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SUMMARY: The U.S. Department of Energy (DOE or Department) has 
determined that the 2009 edition of the International Code Council 
(ICC) International Energy Conservation Code (IECC) (2009 IECC or 2009 
edition) would achieve greater energy efficiency in low-rise 
residential buildings than the 2006 IECC, with site energy savings 
estimated at 14%. Also, DOE has determined that the 2006 edition of the 
ICC IECC (2006 IECC or 2006 edition) would achieve greater energy 
efficiency than the 2003 edition of the ICC IECC (2003 IECC or 2003 
edition), with site energy savings estimated at 1%. Finally, DOE has 
determined that the 2003 edition would not achieve greater energy 
efficiency than the 2000 IECC. Upon publication of this affirmative 
final determination, States are required to file certification 
statements to DOE that they have reviewed the provisions of their 
residential building code regarding energy efficiency and made a 
determination as to whether to update their code to meet or exceed the 
2009 IECC. Additionally, this Notice provides guidance to States on how 
the codes have changed from previous versions, how to submit 
certifications, and how to request extensions of the deadline to submit 
certifications.

DATES: Certification statements by the States must be provided by July 
19, 2013.

ADDRESSES: Certification Statements must be addressed to the Buildings 
Technologies Program-Building Energy Codes Program Manager, U.S. 
Department of Energy, Office of Energy Efficiency and Renewable Energy, 
Forrestal Building, Mail Station EE-2J, 1000 Independence Avenue, SW., 
Washington, DC 20585-0121.

FOR FURTHER INFORMATION CONTACT: Michael Erbesfeld, U.S. Department of 
Energy, Office of Energy Efficiency and Renewable Energy, Forrestal 
Building, Mail Station EE-2J, 1000 Independence Avenue, SW., 
Washington, DC 20585-0121, (202) 287-1874, e-mail: 
michael.erbesfeld@ee.doe.gov. For legal issues contact Chris Calamita, 
U.S. Department of Energy, Office of the

[[Page 42689]]

General Counsel, Forrestal Building, Mail Station GC-72, 1000 
Independence Avenue, SW., Washington, DC 20585-0121, (202) 586-9507, e-
mail: Christopher.Calamita@hq.doe.gov.

SUPPLEMENTARY INFORMATION:

I. Introduction
    A. Statutory Requirements
    B. Background
    C. Preliminary Determination
    D. Public Comments Regarding the Preliminary Determination
    E. DOE's Final Determination Statements
II. Discussion of Changes in the 2003, 2006, and 2009 IECC
    A. 2003 IECC Compared With the 2000 IECC
    B. 2006 IECC Compared With the 2003 IECC
    C. 2009 IECC Compared With the 2006 IECC
III. Comparison of the 2009 IRC to the 2009 IECC
IV. Filing Certification Statements With DOE
    A. State Determinations
    B. Certification
    C. Request for Extensions
V. Regulatory Analysis
    A. Review Under Executive Order 12866
    B. Review Under the Regulatory Flexibility Act
    C. Review Under the National Environmental Policy Act of 1969
    D. Review Under Executive Order 13132, ``Federalism''
    E. Review Under the Unfunded Mandates Reform Act of 1995
    F. Review Under the Treasury and General Government 
Appropriations Act of 1999
    G. Review Under the Treasury and General Government 
Appropriations Act of 2001
    H. Review Under Executive Order 13211
    I. Review Under Executive Order 13175

I. Introduction

A. Statutory Requirements

    Title III of the Energy Conservation and Production Act, as amended 
(ECPA), establishes requirements for the Building Energy Standards 
Program. (42 U.S.C. 6831-6837) Section 304(b) of ECPA, as amended, 
provides that when the 1992 Model Energy Code (MEC), or any successor 
to that code, is revised, the Secretary must determine, not later than 
12 months after the revision, whether the revised code would improve 
energy efficiency in residential buildings and must publish notice of 
the determination in the Federal Register. (42 U.S.C. 6833(a)(5)(A)) 
The Department, following precedent set by the ICC and the American 
Society of Heating, Refrigerating and Air-Conditioning Engineers 
(ASHRAE) considers high-rise (greater than three stories) multifamily 
residential buildings and hotel, motel, and other transient residential 
building types of any height as commercial buildings for energy code 
purposes. Low-rise residential buildings include one- and two-family 
detached and attached buildings, duplexes, townhouses, row houses, and 
low-rise multifamily buildings (not greater than three stories) such as 
condominiums and garden apartments.
    If the Secretary determines that the revision would improve energy 
efficiency then, not later than 2 years after the date of the 
publication of the affirmative determination, each State \1\ is 
required to certify that it has compared its residential building code 
regarding energy efficiency to the revised code and made a 
determination whether it is appropriate to revise its code to meet or 
exceed the provisions of the successor code. (42 U.S.C. 6833(a)(5)(B)) 
State determinations are to be made: (1) After public notice and 
hearing; (2) in writing; (3) based upon findings included in such 
determination and upon evidence presented at the hearing; and (4) 
available to the public. (See, 42 U.S.C. 6833(a)(5)(C)) In addition, if 
a State determines that it is not appropriate to revise its residential 
building code, the State is required to submit to the Secretary, in 
writing, the reasons, which are to be made available to the public. 
(See, 42 U.S.C. 6833(a)(5)(C))
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    \1\ The term State includes ``each of the several States, the 
District of Columbia, the Commonwealth of Puerto Rico, and any 
territory and possession of the United States.'' 42 U.S.C. 6832(11).
---------------------------------------------------------------------------

    In the specific case of this final determination, where DOE is 
publishing the results of three residential determinations at once, 
each state should certify it has compared its residential building code 
regarding energy efficiency to the 2009 IECC and made a determination 
whether it is appropriate to revise its code to meet or exceed the 
provisions of the successor code.

B. Background

    The ICC's IECC establishes national energy efficiency requirements 
for buildings. In 1997, the Council of American Building Officials 
(CABO) was incorporated into the ICC and the MEC was renamed to the 
IECC. A previous Federal Register notice, 59 FR 36173, July 15, 1994, 
announced the Secretary's determination that the 1993 MEC increased 
energy efficiency relative to the 1992 MEC for residential buildings. 
Similarly, another Federal Register notice, 61 FR 64727, December 6, 
1996, announced the Secretary's determination that the 1995 MEC is an 
improvement over the 1993 MEC. Finally, Federal Register notice 66 FR 
1964, January 10, 2001, simultaneously announced the Secretary's 
determination that the 1998 IECC is an improvement over the 1995 MEC 
and the 2000 IECC is an improvement over the 1998 IECC.

C. Preliminary Determination

    DOE published in the Federal Register a Notice of Preliminary 
Determination for the 2003, 2006 and 2009 editions of the IECC that 
preliminarily concluded that the 2009 version of the IECC would achieve 
greater energy efficiency in low-rise residential buildings than the 
2006 IECC. Also, DOE preliminarily determined that the 2006 version of 
the IECC would achieve greater energy efficiency than the 2003 IECC. 
Finally, DOE preliminarily determined that the 2003 version of the IECC 
would not achieve greater energy efficiency than the 2000 IECC. 75 FR 
54131 (Sept. 3, 2010).

D. Public Comments Regarding the Preliminary Determination

    DOE accepted public comments on the preliminary determination for 
the 2003, 2006, and 2009 editions of the IECC until October 4, 2010. 
DOE received submissions from a total of seven different entities.
    The Responsible Energy Codes Alliance (RECA) submitted a written 
comment (Docket No. EERE-2010-BT-DET-0030-0006.1, pgs. 2-4) stating 
that it strongly supports the Department's determination that the 2006 
and 2009 editions of the IECC would achieve greater energy efficiency 
in buildings than the relative previous editions. RECA suggests that 
DOE follow up with the States after publication of the Final 
Determination, as well as making public, on the Department's Web site, 
the certification letters that States submit. RECA went on to comment 
that the Department's decision to publish a Notice of Preliminary 
Determination rather than a Notice of Determination is unnecessary to 
comply with the Energy Policy Act and that adding an extra level of 
administrative procedure is likely to further delay determinations on 
future editions of the model energy codes.
    In response to RECA's comment concerning following up with the 
States in their certification efforts, DOE notes that under section 
304(d) and (e) of ECPA DOE provides technical assistance and funding to 
States that choose to improve and implement State residential building 
energy efficiency codes, including increasing and verifying compliance 
with such codes. As certification letters are received from the States, 
they will be made public on the Department's Web site at http://

[[Page 42690]]

energycodes.gov/states/. The certification letters will also be 
forwarded to the State Energy Program for their consideration. DOE 
further notes that a listing of those States that have submitted 
certification letters from their respective governors under the 
requirements of the American Recovery and Reinvestment Act is available 
at http://www.energy.gov/InYourState.htm. The letters can be found on 
each State's Web site under Recovery Act activity.
    With regard to issuing a preliminary determination, the Department 
believes that there is value in providing an opportunity for public 
comment on its analysis, particularly given that a positive 
determination could potentially impact States.
    The American Chemistry Council (ACC) submitted a written comment 
(Docket No. EERE-2010-BT-DET-0030-0007.1, pg. 1) stating that it 
strongly supports the Department's determination that the 2009 edition 
of the IECC would achieve greater energy efficiency in buildings than 
the 2006 edition.
    The Edison Electric Institute (EEI) submitted a written comment 
(Docket No. EERE-2010-BT-DET-0030-0002.1, pgs. 1-2) supporting the 
preliminary determination with one concern about the analysis. Their 
concern was that the DOE model estimates the annual average baseline 
residential lighting energy usage at 2,373 kWh per year. EEI suggests 
that the annual lighting usage should be closer to 900 kWh per year.
    The basis of DOE's lighting energy assumptions comes from the 2006 
Mortgage Industry National Home Energy Rating Standards developed by 
the Residential Energy Services Network (RESNET), http://www.resnet.us/standards/RESNET_Mortgage_Industry_National_HERS_Standards.pdf , 
pg. 3-19. These standards assume 2,375 kWh/year of lighting energy use 
for a newly constructed 2400 ft \2\ house. The EEI comment references 
data from the 2001 Residential Energy Consumption Survey (RECS), http://www.eia.gov/emeu/recs/recs2001/enduse2001/enduse2001.html, which 
reports average energy usage for all existing housing in the year 2001 
to be 940 kWh/year. DOE used RESNET as opposed to RECS, because it was 
the most up-to-date lighting energy usage estimate for a newly 
constructed 2400 ft \2\ house.\2\ Therefore, DOE considers the 2,375 
kWh for annual lighting energy usage to be a reasonable estimate based 
on RESNET's standards.
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    \2\ Census data reports an average square footage of 2438 ft \2\ 
in 2009. See, http://www.census.gov/const/C25Ann/sftotalmedavgsqft.pdf.
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    The ICC submitted a written comment (Docket No. EERE-2010-BT-DET-
0030-0003.1, pg. 2) stating that DOE's conclusion that the use of the 
2009 IECC will improve energy efficiency in residential buildings that 
are built to meet its requirements is correct.
    The Building Codes Assistance Project (BCAP) submitted a written 
comment (Docket No. EERE-2010-BT-DET-0030-0004.1, pgs. 1-2) supporting 
the DOE's determination and suggesting that DOE follow up with the 
States after publication of the Final Determination, as well as making 
public which States comply with the statutory requirements by updating 
their code, submitting in writing why they are choosing not to update 
their code, or by filing for a formal extension within two years of 
publication. In regards to BCAP's comments see response to RECA's 
comments above.
    The Energy Efficient Codes Coalition (EECC) submitted a written 
comment (Docket No. EERE-2010-BT-DET-0030-0005.1, pg. 2) stating they 
strongly support DOE's determination that the 2009 IECC achieves 
greater energy efficiency than the 2006 IECC.
    The Natural Resources Defense Council (NRDC) submitted a written 
comment (Docket No. EERE-2010-BT-DET-0030-0008.1, pgs. 2-4) stating the 
following three issues: (1) It urges DOE to use this opportunity to 
clarify States' commitments with regards to updating and implementing 
their building energy codes; (2) clarify the limits of preemption of 
testing and labeling of energy conservation of consumer products under 
section 327 of the Energy Policy and Conservation Act EPCA (42 U.S.C. 
6297); and (3) revise the energy efficiency standards for Federal 
buildings to reflect the most recent model energy codes.
    In regards to NRDC's first comment, see response to RECA's comments 
above. In addition, Section IV below describes the process for States 
to file certification statements with DOE. NRDC's second comment is in 
reference to the preemption requirements applicable to the Federal 
energy efficiency standards for appliances. Essentially, section 307(f) 
of ECPA limits the ability of State and local building codes to require 
minimum energy efficiency levels of appliances. (See, 42 U.S.C. 
6297(e)) It is important to note that today's final determination does 
not require States to adopt a specific building code. Today's final 
determination requires a State to certify that it has reviewed the 
provisions of its residential building code regarding energy efficiency 
and made a determination as to whether it is appropriate for such State 
to revise such residential building code provisions to meet or exceed 
the revised code for which the Secretary made such determination. (42 
U.S.C. 6833(a)(5)(B)) Section 304 of ECPA does not prescribe how State 
code provisions must achieve the required energy efficiencies. This 
final determination does not require States to adopt a specific code or 
to require energy efficiency levels of covered appliances as part of 
that code, but rather it allows for States to adopt building codes that 
meet or exceed the energy efficiency requirements of Standard 90.1-
2007. As such, there is no potential conflict between the State code 
provisions of ECPA and the preemption language in EPCA. In response to 
NRDC's final comment, DOE intends to update the baseline standards for 
Federal buildings found in 10 CFR part 433 and 10 CFR part 435 that 
reference IECC following the issuance of this final determination for 
2003, 2006 and 2009 IECC.

E. DOE's Final Determination Statement

    Below is a detailed discussion of the Department's final 
determinations for the 2003, 2006, and 2009 IECCs.
2003 IECC
    DOE's review and evaluation found that there are not significant 
differences in energy efficiency between the 2003 edition and the 2000 
edition of the IECC. Although there are a few changes that would 
modestly improve the energy efficiency of residential buildings, there 
are a number of changes that reduce energy efficiency in certain 
situations. Most of the changes to the IECC between the 2000 and 2003 
editions would not effect energy efficiency but rather make the code 
simpler and clearer for designers, builders, and code compliance 
officials to understand and use. Based on these findings, the 
Department has concluded that the 2003 edition of the IECC should not 
receive an affirmative determination under Section 304(b) of ECPA. The 
Department concludes that there is at best a slight improvement in 
energy efficiency for some residential buildings, but this potential 
improvement is not sufficient to merit an affirmative determination. 
This is discussed in further detail below. It should be noted that DOE 
is not concluding that the energy efficiency of the 2003 IECC is less 
stringent than the 2000 IECC.

[[Page 42691]]

2006 IECC
    The residential portion of the 2006 IECC has been extensively 
changed from that of the 2003 IECC. However, the most significant 
changes to the code between 2003 and 2006 simplify the code format 
rather than fundamentally changing the overall (national average) 
energy efficiency of the code. Multifamily buildings, which in the past 
have had separate, less stringent thermal requirements, are an 
exception. By eliminating the separate requirements, the 2006 IECC 
increased the energy efficiency of multifamily buildings.
    Although the most significant 2006 changes did not directly target 
efficiency improvements, the new format of the code does result in some 
energy efficiency differences. The requirements for any given building 
may have increased or decreased based on the specific location 
(climate) and building design. The Department has found that overall 
the 2006 IECC has an improvement in energy efficiency compared to the 
2003 IECC. The Department concludes that the 2006 edition of the IECC 
receives an affirmative determination under Section 304(b) of EPCA. A 
Technical Support Document (TSD) for the 2006 IECC is available at the 
following Web site; http://www.energycodes.gov/status/determinations_res.stm. DOE has prepared a TSD for the 2006 IECC determination and not 
for the 2003 IECC and 2009 IECC determination for the following 
reasons. The 2006 IECC contained a very extensive change in the format 
of the code compared to the 2003 IECC. In addition, the changes in the 
format to the 2006 IECC reduce energy efficiency in some cases and 
increase energy efficiency in others. DOE deemed that its analysis to 
determine whether energy efficiency was improved in the 2006 IECC would 
be better addressed in a TSD rather than in this Notice. As discussed 
above, for the 2003 IECC determination, there were very few changes 
from the 2000 IECC and therefore no TSD is needed. For the 2009 IECC 
determination, discussed below, there are a substantial number of 
changes that effect energy efficiency, but nearly all these changes are 
clear improvements that will reduce energy use. Therefore, highly 
detailed calculations are not needed to determine whether energy 
efficiency is improved overall in the code and these changes are also 
discussed in this Notice rather than a TSD.
2009 IECC
    The 2009 IECC has substantial revisions compared to the 2006 IECC. 
Many of these revisions appear to directly improve energy efficiency, 
and the sum results of all changes appear to result in a significant 
increase in code stringency. Therefore, the Department concludes that 
the 2009 edition of the IECC receives an affirmative determination 
under Section 304(b) of EPCA.

II. Discussion of Changes in the 2003, 2006, and 2009 IECC

A. 2003 IECC Compared With the 2000 IECC

    As a whole, the 2003 IECC's provisions for energy efficiency in 
residential buildings are largely unchanged from the 2000 IECC. There 
are some changes in the code that can have a modest effect on energy 
efficiency. These are discussed below. In addition, there is a variety 
of minor changes intended to make the code more concise, more complete, 
and better organized, but not more or less stringent. For example, more 
specific requirements have been added for steel roofs/ceilings and 
floors to correspond to those already in the code for steel walls. 
Another example is the relocation of the 51 pages of state maps from 
the middle of the code to the back of the code. Additionally, the 
performance path in chapter 4 of the 2003 IECC contains a variety of 
modest improvements compared to the 2000 IECC, which creates more 
concise requirements.
1. Changes in the 2003 IECC From the 2000 IECC That Improve Energy 
Efficiency
a. Increased Duct Insulation Requirements
    Duct insulation requirements generally increased in the 2003 IECC. 
The 2003 IECC requirements are shown in Table 1. These are somewhat 
difficult to compare to the 2000 IECC requirements because the latter 
are more complex, differing between ducts in unconditioned spaces and 
ducts completely exterior to the building, and distinguishing 
requirements by the design temperature difference between the duct air 
and the space in which the ducts are located.
    The 2000 IECC requirements for ducts in unconditioned spaces are 
shown in Table 2. Assuming typical supply air temperatures of 55[deg]F 
for cooling and 95[deg]F for heating (for heat pumps), the 2000 IECC 
insulation requirement for supply ducts in unconditioned spaces is R-5 
(minimum) for nearly all cases. Insulation required by the 2000 IECC 
for return ducts in unconditioned spaces will generally be R-3.3 in 
warmer climates and R-5 in colder climates.
    For the very common case of supply ducts in attics, which is likely 
to have the greatest impact on energy use, the 2003 IECC always 
requires at least R-8, which exceeds the 2000 IECC's R-5 requirement. 
For supply ducts in other unconditioned spaces, the 2003 IECC's 
requirements exceed the 2000 IECC's requirements in all cases except 
very warm locations (less than 1500 heating degree-days), where the 
2003 IECC requires R-4 compared to the 2000 IECC's requirement of R-5. 
Because supply ducts transport air in its hottest (or coldest) 
condition, insulation has its greatest impact on these ducts. The 2003 
IECC is almost always more stringent than the 2000 IECC for supply 
ducts. This includes all supply ducts in attics and, based on the 
distribution of population,\3\ more than 80% of ducts in other 
unconditioned spaces.
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    \3\ Estimated from USGS Population Places data that allows 
mapping of population to climate (http://geonames.usgs.gov/domestic/download_data.htm).
---------------------------------------------------------------------------

    Requirements for return ducts in attics are slightly more stringent 
in the 2003 IECC than the 2000 IECC (R-4 vs. R-3.3) in the warmest 
climates, slightly less stringent (R-4 vs. R-5) in mid climates, and 
slightly more stringent (R-6 vs. R-5) in the coldest climates.
    Research \4\ showing the impact on heating and cooling energy use 
due to duct insulation is summarized in Table 3. Based on this 
research, the Department estimates that improved duct insulation in the 
2003 IECC will reduce heating and cooling energy use by about 1%.
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    \4\ Triedler, B., R. Lucas, M. Modera, J. Miller. 1996. Impact 
of Residential Duct Insulation on HVAC Energy Use and Life-Cycle 
Costs to Consumers. American Society of Heating, Refrigerating, and 
Air-Conditioning Engineers.

[[Page 42692]]

                             Table 1--Duct Insulation Requirements in the 2003 IECC
----------------------------------------------------------------------------------------------------------------
                                                      Insulation R-value (h[middot] ft \2\[middot][deg]F)/Btu
                                                 ---------------------------------------------------------------
                                                   Ducts in unconditioned attics      Ducts in unconditioned
    Annual heating degree days base 65 [deg]F           or outside building        basements, crawl spaces, and
                                                 --------------------------------   other unconditioned spaces
                                                                                 -------------------------------
                                                      Supply          Return          Supply          Return
----------------------------------------------------------------------------------------------------------------
Below 1,500.....................................               8               4               4               0
1,500 to 3,500..................................               8               4               6               2
3,501 to 7,500..................................               8               4               8               2
Above 7,500.....................................              11               6              11               2
----------------------------------------------------------------------------------------------------------------

 Table 2--Insulation Requirements (R-Value, h-ft\2\-F/Btu) for Ducts in
                  Unconditioned Spaces in the 2000 IECC
------------------------------------------------------------------------
     Design Temperature
 Difference (TD) between air
   temperature in duct and           Cooling               Heating
   space in which duct is
     located (degrees F)
------------------------------------------------------------------------
TD = TD > 15...............  3.3.................  3.3
TD > 40.....................  5.0.................  5.0
------------------------------------------------------------------------

  Table 3--Heating and Cooling Energy Savings (percent) From Increased
             Duct Insulation (Atlanta, Natural Gas Heating)
------------------------------------------------------------------------
                                          Attic     Basement  Crawlspace
------------------------------------------------------------------------
R-4 to R-6............................        2.3        1.6         1.8
R-6 to R-8............................        1.4        0.9         1.1
------------------------------------------------------------------------

b. Minor Changes to ``Systems Analysis'' Performance Compliance Method
    There are two changes that can increase the stringency of the 
performance path in Chapter 4 of the 2003 IECC in certain cases. First, 
any house proposed to use electric resistance heating must have equal 
or lower calculated energy use than a hypothetical ``standard design'' 
that uses a more efficient electric air source heat pump. This change 
makes the performance approach much more stringent for designs that 
have electric resistance heating. However, compliance can be achieved 
for these designs using the prescriptive compliance methods in chapters 
5 and 6, thereby bypassing the increased stringency of the performance 
path.
    Second, a provision has also been added requiring that the least 
efficient orientation in terms of energy use be assumed for a proposed 
group of residences with identical designs. Therefore, in a development 
where the same design is built on multiple lots facing various 
directions, the compliance analysis must be based on the least 
advantageous orientation. In most of the United States, this is the 
orientation that points the most window area toward a westerly 
direction, maximizing solar heat gains in summer afternoons and 
therefore increasing air conditioning energy use. Because proposed 
building designs must have a calculated annual energy use equal to or 
less than that of a home with window area equally distributed toward 
the four cardinal directions, the requirement to assume the least 
efficient orientation effectively makes the code more stringent because 
the increased energy use from the least efficient orientation must be 
offset by improved energy efficiency. This requirement in the 2003 IECC 
will have only modest average impact because it affects only the 
performance approach and identical house designs used repeatedly in a 
development.
2. Changes in the 2003 IECC From the 2000 IECC That Decrease Energy 
Efficiency
a. Sunroom Additions
    A special set of requirements has been added to Table 502.2.5 of 
the 2003 IECC for sunroom additions having a floor area of less than 
500 ft\2\ (46.5 m\2\). Sunroom additions are permitted to have ceiling, 
wall insulation, and window U-factor requirements that are typically 
less stringent than the requirements for all other types of residential 
construction. These special requirements for sunrooms only apply to 
additions to existing dwellings, not to sunrooms that are built as part 
of a new dwelling. In the 2000 IECC, there were no special requirements 
for sunroom additions; they had to meet the same requirements as other 
residential construction. To qualify for the less stringent 
requirements in the 2003 IECC, the sunroom addition must be capable of 
being controlled as a separately heated and cooled zone. Additionally, 
new walls, doors or windows between the sunroom and the house must meet 
the envelope requirements of the IECC. Finally, the glazing area must 
exceed 40% of the gross area of the exterior walls and roof to qualify 
as a sunroom in the IECC.
    Testing with the EnergyGuage (DOE-2) \5\ simulation tool indicates 
that for a 500 ft\2\ sunroom, the less stringent 2003 requirements 
could add about $200 to the annual energy costs in Chicago if the 
sunroom is both heated and cooled all year. Impacts are much smaller in 
Houston, about $10 added energy costs. However, this increase in energy 
consumption is mitigated (on average) by several factors. First, the 
requirements apply to a very small fraction of all new residential 
construction. The Wall Street Journal

[[Page 42693]]

Online (June 3, 2003) reports $3 billion worth of sunroom construction 
each year, or less than one percent of all residential construction 
expenditures. But that fraction includes new construction as well as 
additions, so the fraction representing sunroom additions is less than 
1%. Second, it is expected that many sunrooms will not be maintained at 
comfort conditions all year, further reducing the overall impact. 
Finally, because the 2003 IECC requires that the sunroom be thermally 
isolated from the rest of the house and that walls, windows, and doors 
between the sunroom and house meet the code's envelope requirements, 
the thermal impact when these spaces are not actively conditioned is 
negligible. Therefore, the overall impact of this reduction in 
stringency to national energy use is expected to be extremely small.
---------------------------------------------------------------------------

    \5\ EnergyGuage (DOE-2) simulation tool is available at http://doe2.com/.
---------------------------------------------------------------------------

b. Climate Zone Maps
    The IECC contains prescriptive envelope requirements (insulation R-
values and glazing U-factors) in Chapter 6 and Section 502.2.4 of the 
code. In the 2000 IECC, only the heating degree-days for the city where 
the housing was to be built could be used to determine the applicable 
prescriptive envelope requirements. In the 2003 IECC, the heating 
degree-days can still be used to determine the requirements, but 
additionally the designer/builder can use the climate zones provided in 
the state maps in the IECC. For most locations, the Chapter 3 climate 
zones and heating degree-days lead to the exact same requirements. 
Using the climate zones in the maps instead of the heating degree-days 
will allow about 10% of cities nationwide to have a less stringent set 
of prescriptive requirements. However, about 20% of cities nationwide 
will have more stringent requirements when the climate zones are used 
with the prescriptive requirements. If the designer/builders select to 
use the climate zone maps in the 10% of cities where it lowers 
requirements but not in the 20% of locations where it raises 
requirements, the 2003 code effectively is less stringent. However, DOE 
believes code users will make use of the climate zone maps even in many 
of the locations where they raise requirements. DOE does not anticipate 
that most code users will go through the level of effort of determining 
which method of determining climate based requirements may give less 
stringent requirements. In fact, DOE believes most users will not even 
be aware of these differences, but will prefer the climate zone maps 
because of their simplicity. The REScheck compliance materials 
developed by the DOE utilize the same heating degree day based 
requirements for both the 2000 and 2003 IECC.
c. Increased U-Factor for Skylight Replacements
    The maximum U-factor for skylight replacements in existing 
buildings (Section 502.2.5 of the IECC) is raised from a U-factor of 
0.50 to a U-factor of 0.60 for locations above 1,999 heating degree-
days. A higher U-factor reduces energy efficiency.
3. Net Impact of Changes in the 2003 IECC From the 2000 IECC on Energy 
Efficiency
    Ultimately, the DOE finds that the net impact of the changes in the 
2003 IECC on energy efficiency is not sufficient to merit an 
affirmative determination.
    The change in the 2003 IECC that is expected to have the greatest 
impact on the nation's energy efficiency is the improved duct 
insulation, because a majority of new residential buildings have ducts 
that pass through attics, crawl spaces, unheated basements and other 
spaces where the IECC requires duct insulation. The improved duct 
insulation in the 2003 IECC is estimated to save about 1% of heating 
and cooling costs.
    DOE believes that the changes to the system analysis method are not 
sufficient to sway the decision on whether the determination is 
affirmative or not. This performance compliance method is less commonly 
used, and, as it is optional, the modest energy savings from the 
improvements in this compliance method can easily be bypassed by 
choosing a different method.
    Although the changes that effect sunroom additions and skylight 
replacements reduce energy efficiency, DOE does not believe that they 
will lead to substantial impacts on national energy use, as they do not 
apply to new buildings and only apply to specific types or retrofits 
and additions to existing buildings. The skylight U-factor change is 
only a modest reduction in energy efficiency and sunroom additions are 
a small fraction of the residential construction market.
    The addition of the climate zone maps in the 2003 IECC as an option 
to using city-specific heating degree-day data allows for the 
possibility of preferentially lowering thermal envelope requirements in 
about 10% of all national locations. However, it will be difficult to 
exploit this change because the code user must perform relatively 
complex calculations rather than using the popular and user-friendly 
REScheck software.
    In sum, DOE concludes the changes to duct insulation requirements 
will slightly improve energy efficiency in most houses, however, the 
reductions in energy efficiency for skylight replacements and sunroom 
additions are expected to at least partially offset these savings from 
a national energy total use perspective. Additionally, the vast 
majority of all requirements in the IECC are unchanged from 2000 to 
2003. For these reasons, DOE finds insufficient improvements in the 
2003 IECC to merit an affirmative determination.

B. 2006 IECC Compared With the 2003 IECC

1. Changes in the 2006 IECC From the 2003 IECC That Improve Energy 
Efficiency
    The residential portion of the IECC in general and the building 
thermal envelope (ceilings, walls, doors, windows, foundations, etc.) 
requirements in particular were completely restructured from 2003 to 
2006. This resulted in the code becoming much shorter and simpler, its 
volume reduced from 38 pages to 9 pages. The climate basis on which 
envelope requirements depend was completely reworked. The 2003 IECC has 
envelope requirements that vary continuously with heating degree-days 
(HDD),\6\ or with 17 HDD zones (geographically-defined based on 
counties, roughly following 500-HDD bins). In contrast, the 2006 IECC 
has eight geographically-defined climate zones with all borders set on 
county boundaries.
---------------------------------------------------------------------------

    \6\ Some compliance paths defined requirements based on 17 
``zones'' based on HDD ranges.
---------------------------------------------------------------------------

    A major change to envelope requirements was the combining of 
separate 2003 IECC requirements for two building categories (1) One- 
and two-family dwellings, and (2) all other low-rise residential 
buildings \7\. The 2006 IECC requirements are the same for all low-rise 
residential building types, which has the effect of increasing the 
energy efficiency of the second category, all other low-rise buildings. 
Also

[[Page 42694]]

eliminated were nine related tables that provided predefined packages 
of thermal transmittance prescriptive requirements (glazing, ceiling-
roof, exterior wall, floor over unconditioned space, basement and crawl 
space walls, and floor slab on grade) for different window to wall area 
ratios (WWR). In their place, the 2006 IECC provides a single table of 
predefined packages of thermal transmittance prescriptive requirements 
that do not vary with WWR.
---------------------------------------------------------------------------

    \7\ The 2006 IECC defines residential buildings as ``R-3 
buildings, as well as R-2 and R-4 buildings three stories or less in 
height above grade''. The R-2/3/4 designation is from the 
International Building Code and these are defined as follows:
    R-2--Apartment houses, boarding houses, convents, dormitories, 
fraternities and sororities, monasteries.
    R-3--one or two family dwellings.
    R-4--Residential Care/Assisted living.
    R-2 and R-4 buildings that have more stories are covered 
commercial codes.
---------------------------------------------------------------------------

    Table 4 shows a comparison of major prescriptive envelope 
requirements for a single-family house at a typical 15% WWR. The 
requirements for the 2003 IECC will differ from those shown in Table 4 
for other WWRs and for multifamily buildings. The 2006 IECC climate 
zones do not exactly map to the 2003 IECC zones. Table 5 shows a more 
detailed estimate of how residential construction maps from the 2006 
IECC compare to the 2003 IECC climate zones.

Table 4--Comparison of the 2003 IECC and 2006 IECC Envelope Thermal Component Prescriptive Criteria for One- and Two-Family Dwellings at 15% Window Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
         IECC climate zone                                               Maximum                                     Minimum
------------------------------------                             ---------------------------------------------------------------------------------------
                                         Heating degree days        Glazing U-factor       Ceiling R-value        Wall  R-value        Floor  R-value
          2003              2006                                 ---------------------------------------------------------------------------------------
                                                                     2003       2006       2003       2006       2003       2006       2003       2006
--------------------------------------------------------------------------------------------------------------------------------------------------------
1......................        1 2   0-499......................        Any       1.20       R-13       R-30       R-11       R-13       R-11       R-13
2......................          2   500-999....................       0.90       0.75       R-19       R-30       R-11       R-13       R-11       R-13
3......................  ..........  1,000-1,499................       0.75       0.75       R-19       R-30       R-11       R-13       R-11       R-13
4......................  ..........  1,500-1,999................       0.75       0.75       R-26       R-30       R-13       R-13       R-11       R-13
5......................          3   2,000-2,499................       0.65       0.65       R-30       R-30       R-13       R-13       R-11       R-19
6......................  ..........  2,500-2,999................       0.60       0.65       R-30       R-30       R-13       R-13       R-19       R-19
7......................  ..........  3,000-3,499................       0.55       0.65       R-30       R-30       R-13       R-13       R-19       R-19
8......................          4   3,500-3,999................       0.50       0.40       R-30       R-38       R-13       R-13       R-19       R-19
9......................  ..........  4,000-4,499................       0.45       0.40       R-38       R-38       R-13       R-13       R-19       R-19
10.....................  ..........  4,500-4,999................       0.45       0.40       R-38       R-38       R-16       R-13       R-19       R-19
11.....................          5   5,000-5,499................       0.45       0.35       R-38       R-38       R-18       R-19       R-19    R-19/30
12.....................  ..........  5,500-5,999................       0.40       0.35       R-38       R-38       R-18       R-19       R-21    R-19/30
13.....................  ..........  6,000-6,499................       0.35       0.35       R-38       R-38       R-18       R-19       R-21    R-19/30
14.....................  ..........  6,500-6,999................       0.35       0.35       R-49       R-38       R-21       R-19       R-21    R-19/30
15.....................        5 6   7,000-8,499................       0.35       0.35       R-49    R-38/49       R-21       R-19       R-21       R-21
16.....................          6   8,500-8,999................       0.35       0.35       R-49       R-49       R-21       R-21       R-21       R-21
17.....................          7   9,000-12,999...............       0.35       0.35       R-49       R-49       R-21       R-21       R-21       R-21
--------------------------------------------------------------------------------------------------------------------------------------------------------

  Table 4 Continued--Comparison of the 2003 IECC and 2006 IECC Envelope Thermal Component Prescriptive Criteria
                              for One- and Two-Family Dwellings at 15% Window Area
----------------------------------------------------------------------------------------------------------------
     IECC climate zone                                                       Minimum
---------------------------                    -----------------------------------------------------------------
                              Heating degree      Basement wall  R-     Slab perimeter R-   Crawl space wall  R-
                                   days                 value         value and depth feet          value
     2003          2006                        -----------------------------------------------------------------
                                                   2003       2006       2003       2006       2003       2006
----------------------------------------------------------------------------------------------------------------
1.............        1 2   0-499.............        R-0        R-0        R-0        R-0        R-0        R-0
2.............          2   500-999...........        R-0        R-0        R-0        R-0        R-4        R-0
3.............  ..........  1,000-1,499.......        R-0        R-0        R-0        R-0        R-5        R-0
4.............  ..........  1,500-1,999.......        R-5        R-0        R-0        R-0        R-5        R-0
5.............          3   2,000-2,499.......        R-5    R-10/13        R-0        R-0        R-6        R-5
6.............  ..........  2,500-2,999.......        R-6    R-10/13      R-4,2        R-0        R-7        R-5
7.............  ..........  3,000-3,499.......        R-7    R-10/13      R-4,2        R-0        R-8        R-5
8.............          4   3,500-3,999.......        R-8    R-10/13      R-5,2     R-10,2       R-10       R-10
9.............  ..........  4,000-4,499.......        R-8    R-10/13      R-5,2     R-10,2       R-11       R-10
10............  ..........  4,500-4,999.......        R-9    R-10/13      R-6,2     R-10,2       R-17       R-10
11............          5   5,000-5,499.......        R-9    R-10/13      R-6,2     R-10,2       R-17       R-10
12............  ..........  5,500-5,999.......       R-10    R-10/13      R-9,4     R-10,2       R-19       R-10
13............  ..........  6,000-6,499.......       R-10    R-10/13      R-9,4     R-10,2       R-20       R-10
14............  ..........  6,500-6,999.......       R-11    R-10/13     R-11,4     R-10,2       R-20       R-10
15............        5 6   7,000-8,499.......       R-11    R-10/13     R-13,4     R-10,2       R-20       R-10
16............          6   8,500-8,999.......       R-18    R-10/13     R-14,4     R-10,4       R-20       R-10
17............          7   9,000-12,999......       R-19    R-10/13       R-18     R-10,4       R-20       R-10
----------------------------------------------------------------------------------------------------------------

 Table 5--Percentage of Homes in Each 2006 IECC Climate Zone That Would Have Been in Each 2003 IECC Climate Zone
----------------------------------------------------------------------------------------------------------------
                                                                2006 IECC climate zone
                                    ----------------------------------------------------------------------------
       2003 IECC climate zone                                          4 except    5 and
                                         1          2          3        Marine    Marine 4      6        7 & 8
----------------------------------------------------------------------------------------------------------------
1..................................        100          5          0          0          0          0          0
2..................................          0         20          0          0          0          0          0
3..................................          0         40         22          0          0          0          0
4..................................          0         31         10          0          0          0          0
5..................................          0          3         18          0          0          0          0

[[Page 42695]]

 
6..................................          0          0         28          0          0          0          0
7..................................          0          0         16          4          0          0          0
8..................................          0          0          6          9          0          0          0
9..................................          0          0          0         13          1          0          0
10.................................          0          0          0         28          6          0          0
11.................................          0          0          0         41          8          0          0
12.................................          0          0          0          5         28          0          0
13.................................          0          0          0          0         31          0          0
14.................................          0          0          0          0         20         12          0
15.................................          0          0          0          0          6         81          3
16.................................          0          0          0          0          0          5          6
17.................................          0          0          0          0          0          2         85
18.................................          0          0          0          0          0          0          5
19.................................          0          0          0          0          0          0          2
----------------------------------------------------------------------------------------------------------------

2. Net Impact of Changes From the 2003 to 2006 IECC
    The Department has conducted an analysis and has found that the 
2006 IECC would modestly increase energy efficiency on an overall 
national average basis. This analysis is summarized below; a TSD 
published in conjunction with this Notice contains the full results. 
The Department stresses that this increased energy efficiency is based 
on an average across all new residential buildings. The analysis 
identified combinations of locations and building design where the 2006 
IECC would slightly reduce energy efficiency; however, the analysis 
indicates that the reductions would be more than offset by cases where 
energy efficiency is improved.
    Table 6 provides the overall results of the comparative analysis of 
the prescriptive envelope requirements of the 2006 IECC and the 2003 
IECC. The DOE-2 energy simulation software was used to calculate these 
values. The 2006 IECC has a 1% average overall national energy savings. 
The table shows combined results for single-family and multifamily 
construction accounting for weighted average building characteristics. 
Table 6 illustrates significant regional differences that are primarily 
a result of the revised climate zones. In most climates, the two codes 
are very nearly equivalent. In climate zone 5, the 2006 IECC shows a 
substantial improvement (about 5%). In climate zone 3, the 2003 IECC is 
more energy efficient (by about 5%).

   Table 6--Annual Energy Savings (MBtu) of 2006 IECC Compared to 2003 IECC for Prescriptive Building Envelope
                                                  Requirements
----------------------------------------------------------------------------------------------------------------
                                                   Foundation Type
                              --------------------------------------------------------                 Percent
    2006 IECC climate zone        Heated                     Slab-on-      Unheated       Average      savings
                                 basement     Crawl space      grace       basement
----------------------------------------------------------------------------------------------------------------
Zone 1.......................           0.5           0.4           0.3           0.4           0.3            2
Zone 2.......................          -0.1           1.4           0.9          -0.1           0.9            3
Zone 3.......................          -8.6          -1            -3.3          -1.5          -3.4           -5
Zone 4.......................           2             0.8           0.6           0.7           1.1            1
Zone 5.......................           5.5           7.3           4.2           6.3           5.7            5
Zone 6.......................           1.1           3.3           0             2.3           1.4            1
Zone 7.......................          -2             4.5           0.4           3.4          -0.4            0
Average......................           2.4           2.7          -0.3           3.3           1              1
----------------------------------------------------------------------------------------------------------------

    The analysis underlying the results in Table 6 does not account for 
all changes in the IECC from 2003 to 2006. For example, the 2006 IECC 
requires increased duct insulation in certain cases. On the other hand, 
the 2006 IECC is missing requirements for pool heater controls (on-off 
switch) and pool covers contained in the 2003 IECC. However, these and 
a few other miscellaneous changes do not appear to alter a 
determination that the 2006 IECC has a modest improvement in overall 
energy efficiency compared to the 2003 IECC. The Department expects all 
heated pools to have an on-off switch, basic pool covers are dependent 
on the diligent occupant behavior for removing/covering the pool, and 
many homes do not have a pool or may not heat their pool. Furthermore, 
the 2003 IECC allows the pool cover requirement to be bypassed if 20% 
of the heating energy is provided by solar heat from the sun striking 
the pool surface.
    There was one particular issue that received the most extensive 
debate during the 2006 IECC development process. This issue was how the 
2006 IECC sets requirements based on the window area of a home. There 
was considerable concern because a residential building with unlimited 
windows (e.g., an ``all glass'' house) can be built without any penalty 
under the 2006 IECC. This is not the case in the 2003 IECC, where, as 
the WWR becomes higher, the code requires improved performance of 
windows and/or wall insulation. However, this effect is offset in two 
ways. First, while the 2003 IECC becomes more stringent at high WWRs,

[[Page 42696]]

it also becomes less stringent at low WWRs, whereas the 2006 IECC does 
not. Second, the 2006 IECC increased the baseline efficiency 
requirements (U-factor) of glazing to almost equal then-current Energy 
Star levels in most locations. The Department's analysis of the IECC's 
requirements related to window area indicate that the 2006 code is not 
less stringent than the 2003 IECC when the distribution of window areas 
in all residential buildings is accounted for.
    A major factor influencing the Department's final determination of 
improved efficiency in the 2006 IECC is the improvement in energy 
efficiency for multifamily housing. The building envelope requirements 
in 2006 IECC are identical for all residential building types. This is 
not the case in the 2003 IECC where the requirements for multifamily 
building types are considerably less stringent than those for one and 
two-family dwellings. This is shown in the wall requirements in Figure 
502.2(1) of the 2003 IECC. While multifamily residential construction 
has a much smaller market share than single-family in terms of number 
of dwelling units, there is a nearly universal improvement in 
requirements for multifamily buildings regardless of building design or 
climate zone. As indicated below in the certification discussion, high-
rise (greater than three stories) multifamily residential buildings and 
hotel, motel, and other transient residential building types of any 
height are classified as commercial buildings for energy code purposes. 
However, the building envelope revisions in 2006 IECC would impact 
residential buildings such as townhouses, row houses, and low-rise 
multifamily buildings (not greater than three stories) such as 
condominiums and garden apartments.

C. 2009 IECC Compared With the 2006 IECC

1. Changes in the 2009 IECC From the 2006 IECC That Improve Energy 
Efficiency
    Each of the major changes in the 2009 IECC that impact energy 
efficiency is examined individually below. All but one of the changes 
improve energy efficiency.
1. Changes That Improve Energy Efficiency
a. Lighting
    The 2009 IECC has a major new requirement that a minimum of 50% of 
all lamps (bulbs, tubes, etc.) be ``high efficacy,'' which is defined 
to include compact fluorescent lights (CFLs), T-8 or smaller diameter 
fluorescent tubes, or other products achieving comparable or better 
lumen-per-watt ratings. Traditional incandescent bulbs do not meet this 
requirement. The 2006 IECC had no lighting requirements for residential 
buildings. The Department has referenced the 2006 Mortgage Industry 
National Home Energy Rating Standards developed by the Residential 
Energy Services Network (RESNET) to assume 2,375 kWh/year of lighting 
energy use for a newly constructed 2400 ft\2\ house. The new lighting 
requirements in the 2009 IECC could reduce this lighting energy use by 
about 25%.
b. Building Envelope Thermal Measures
    The 2009 IECC has a number of changes that improve energy 
efficiency in the building envelope. There are direct increases in 
prescriptive building envelope requirements in Tables 402.1.1 and 
402.1.3 of the IECC. Table 7 below shows these changes. Additionally, 
there were a number of minor improvements, including establishing an 
area limit of 24 ft\2\ on the door exemption from U-factor 
requirements.

       Table 7--Improvements in Prescriptive Envelope Requirements
------------------------------------------------------------------------
            Component                  2006 IECC           2009 IECC
------------------------------------------------------------------------
Maximum fenestration U-factor     Zone 2: 0.75......  Zone 2: 0.65.
 (excluding skylights).           Zone 3: 0.65......  Zone 3: 0.50.
                                  Zone 4: 0.40......  Zone 4: 0.35.
Maximum fenestration solar heat   0.40..............  0.30.
 gain coefficient (SHGC) in
 Zones 1 through 3.
Basement wall insulation in       R-13 cavity or R-   R-19 cavity or R-
 Zones 6 through 8.                10 continuous       15 continuous
                                   insulation.         insulation.
Basement wall insulation in       No insulation       R-13 cavity or R-5
 northern section of Zone 3.       required.           continuous
                                                       insulation.
Wood-Frame wall insulation (all   R-19..............  R-20.
 but basements) in Zones 5 and 6.
Floor insulation in Zones 7 and   R-30..............  R-38.
 8.
------------------------------------------------------------------------

c. Building Envelope Air Leakage
    Although the fundamental requirement to seal all potential sources 
of leaks has not changed, the air leakage control specifications in 
Section 402.4 of the 2009 IECC are considerably more detailed than in 
the 2006 edition, requiring either a comprehensive inspection against a 
checklist of component sealing criteria or a whole-building 
pressurization test. There is a new requirement that fireplaces have 
gasketed doors to limit air leakage. Additionally, compliance with 
Standard ASTM E283 is now required to limit air leakage through 
recessed light fixtures. The 2006 IECC only required recessed light 
fixtures to be sealed but did not require compliance with the ASTM 
standard. This testing of fixtures is expected to help eliminate energy 
consuming leaks through these fixtures, which can be a very common 
method of lighting in kitchens and other rooms in new houses.
d. Duct Leakage Limits and Testing Requirement
    The 2009 IECC contains a new requirement that buildings with ducts 
that pass outside the conditioned space (for example, if ducts are in 
unconditioned attics, garages or crawlspaces) have the ducts pressure 
tested and shown to have a maximum leakage rate below specified limits. 
While the 2006 IECC also requires ducts to be sealed, the addition of a 
specific leakage limit verified by a pressure test in each new home or 
retrofit is expected to substantially reduce leakage in many if not 
most cases.
    Testing of completed homes in Washington State where prescriptive 
code requirements for duct sealing apply without any testing to confirm 
compliance, ``showed no significant improvement'' over non-code 
homes.\8\ Another study from Washington State

[[Page 42697]]

concluded: ``Comparisons to air leakage rates reported elsewhere for 
homes built before the implementation of the 1991 WSEC show no 
significant improvement by the general population'' despite years of 
training emphasizing duct sealing.\9\
---------------------------------------------------------------------------

    \8\ Washington State University. 2001. Washington State Energy 
Code Duct Leakage Study Report. WSUCEEP01105. Washington State 
University Cooperative Extension Energy Program, Olympia, 
Washington.
    \9\ Hales, D., A. Gordon, and M. Lubliner. 2003. Duct Leakage in 
New Washington State Residences: Findings and Conclusions. ASHRAE 
Transactions. KC-2003-1-3.
---------------------------------------------------------------------------

    Numerous other studies around the nation show substantial duct 
leakage in new homes, including those in States with codes requiring 
duct sealing. For example, a 2001 study of 186 houses built under the 
MEC in Massachusetts reported ``serious problems were found in the 
quality of duct sealing in about 80% of these houses''.\10\ 
Pressurization tests in 22 of these houses found an average leakage to 
the outside of the house of 183 cfm, or 21.6% of the system flow, at a 
pressure of 25 Pascals.
---------------------------------------------------------------------------

    \10\ Xenergy. 2001. Impact Analysis Of The Massachusetts 1998 
Residential Energy Code Revisions. http://www.mass.gov/Eeops/docs/dps/inf/inf_bbrs_impact_analysis_final.pdf.
---------------------------------------------------------------------------

    The energy savings of improved duct sealing are very substantial. A 
California study estimated a sales-weighted state annual average 
savings from duct sealing of 38 therms and 239 kWh for a 1761 ft\2\ 
house.\11\ This is based on an estimated 12% improvement in duct 
efficiency based on previous studies indicating a 12-15% improvement 
potential. The Department concludes that the 2009 IECC's requirement 
that duct air leakage meet an upper limit and be verified by a pressure 
test will save significant energy compared to the 2006 and prior 
editions of the IECC.
---------------------------------------------------------------------------

    \11\ Hammon, R. W., and M. P. Modera. 1999. ``Improving the 
Efficiency of Air Distribution Systems in New California Homes-
Updated Report.'' Consol. Stockton, California. http://www.energy.ca.gov/title24/ducttape/documents/IMPROVE_EFFICIENCY_RES.PDF.
---------------------------------------------------------------------------

e. Improvement in Other Requirements
    There are a number of changes to the ``simulated performance 
alternative'' compliance path in the 2009 IECC. The glazing area in the 
baseline ``standard reference design'' was reduced from a maximum of 
18% of the conditioned floor area to 15%. This results in increased 
energy efficiency for any proposed design having a glazing area of more 
than 15%. Because use of this compliance path is completely optional, 
these savings will only occur when the user chooses this compliance 
path. Another change does not directly alter code stringency in the 
performance path but may ultimately result in some energy savings is 
the removal of the option to trade high-efficiency HVAC equipment for 
reductions in other requirements in the code, such as reduced envelope 
insulation. Because building envelopes have substantially longer lives 
than HVAC and/or water heating equipment, energy savings from envelope 
improvements may persist for many more years than comparable equipment 
improvements. Also, because high-efficiency equipment is already the 
predominant choice in many markets, disallowing envelope/equipment 
trade-offs is likely to result in improved overall efficiency in many 
situations.
2. Changes in the 2009 IECC From the 2006 IECC That Reduce Energy 
Efficiency
    There is only one change in the 2009 IECC that directly reduces 
energy efficiency. Insulation requirements for many ducts outside the 
building thermal envelope are reduced from R-8 to R-6; exceptions are 
supply ducts in attics, which must still have R-8 insulation, and ducts 
in floor trusses, which retain the 2006 code's R-6 requirement.
3. Net Impact of Changes From the 2009 IECC to 2009 IECC on Energy 
Efficiency
    The Department has conducted an energy simulation analysis of 2009 
IECC compared to the 2006 using the DOE-2 simulation tool to model \12\ 
a typical single family house:
---------------------------------------------------------------------------

    \12\ The DOE-2 simulation tool is available at http://doe2.com/.
---------------------------------------------------------------------------

     2400 ft2 floor area, two-story.
     Crawl space foundation.
     8.5-ft high ceilings.
     A ceiling area (bordering the unconditioned attic) of 
1,200 ft\2\,
     A gross exterior wall area of 2,380 ft\2\,
     And a window area of 357 ft\2\ (15% of the wall area) 
equally oriented north, south, east, and west.
     Heating with a natural gas furnace ($1.20/therm).
     Central electric air conditioning ($.12/kWh).
    High-efficacy lighting was assumed to increase from 10% to 50% of 
all lighting within the building, reducing lighting energy use by 26%, 
or $74 a year. Savings attributable to the lighting requirements in the 
IECC will decrease as Federal law requires improved light bulbs in 2012 
to 2014. Improved duct sealing was assumed to save 10% of the heating 
and cooling costs.
    Figure 1 shows the estimated annual energy cost savings resulting 
from the Department's energy simulation analysis of the 2009 IECC 
changes for 14 diverse climates and for the national average. The 
energy simulation analysis, as described above, takes into account 
changes involving the space heating, space cooling (air conditioning), 
and lighting systems. A 10% reduction is applied to solely the heating 
and cooling energy to account for the improved duct sealing necessary 
to achieve the low duct leakage rates specified in the 2009 IECC. The 
10% reduction is applied post energy simulation analysis to all 14 
climate locations and is accounted for in the cost savings presented in 
Figure 1.

[[Page 42698]]

[GRAPHIC] [TIFF OMITTED] TN19JY11.121

III. Comparison of the 2009 IRC to the 2009 IECC

    In the past, some States have adopted the ICC's International 
Residential Code (IRC) in lieu of the IECC, because the IRC provides a 
comprehensive building construction code (structural, plumbing, 
electrical, energy, etc.) in a single book for one- and two-family 
dwellings and townhouses. Consequently, DOE anticipates that some 
States may wish to adopt the 2009 IRC in lieu of the 2009 IECC. In 
order to provide technical assistance to States that may wish to adopt 
the 2009 IRC, DOE has evaluated the 2009 IRC to compare the stringency 
of its energy provisions with those of the 2009 IECC. Our analysis 
indicates that the 2009 IRC would not equal or exceed the energy 
efficiency of the 2009 IECC.

A. Changes That Reduce Energy Efficiency or Have the Potential To 
Increase Energy Consumption

    Chapter 11 of the IRC contains energy efficiency provisions. The 
IRC allows compliance with the IECC as an alternative to complying with 
Chapter 11. Most of the energy efficiency requirements in the IRC and 
IECC are identical. However, there are several differences between the 
two codes that result in the 2009 IRC having reduced energy efficiency 
compared to the 2009 IECC. All the differences that reduce efficiency 
are listed below:
    1. The 2009 IECC requires a glazed fenestration solar heat gain 
coefficient (SHGC) of 0.30 or lower whereas the 2009 IRC requires a 
higher (less stringent) SHGC of 0.35 or lower, in climate zones 1, 2, 
and 3. Further, the 2009 IRC allows impact resistant fenestration in 
zones 1 through 3 to meet an even less stringent SHGC requirement of 
0.40 and less stringent U-factor requirements in zones 2 and 3.
    2. For basement walls, the 2009 IECC requires either R-15 
continuous insulation or R-19 cavity insulation in zones 6-8, whereas 
the 2009 IRC requires lower (less stringent) R-values in these zones: 
R-10 continuous or R-15 cavity.
    3. The 2009 IECC requires R-38 floors in zones 7 and 8; the 2009 
IRC requires only R-30.
    4. The 2009 IECC limits the allowance for R-30 insulation in 
ceilings without attics to 500 ft\2\ or 20% of the total insulated 
ceiling area, whichever is less. The 2009 IRC limits the allowance to 
500 ft\2\ without regard to the total ceiling area. Thus, under the 
2009 IRC some smaller homes will have less efficient ceilings.
    Additionally, the 2009 IRC differs from the 2009 IECC in some ways 
that, although they do not reduce the stringency of code requirements, 
have the potential to result in increased energy consumption in certain 
situations:
    1. Both the IRC and IECC allow for ``trade-offs'' by which the 
efficiency of one building component can be lowered in trade for higher 
efficiency in another. The 2009 IECC limits the extent to which glazing 
properties can be reduced in such trade-offs. The 2009 IECC sets a 
trade-off ``cap'' on SHGC at a maximum of 0.50 in climate zones 1, 2, 
and 3 and a cap on U-factor trade-offs of U-0.48 in zones 4 and 5 and 
U-0.40 in zones 6, 7, and 8. These caps are not present in the 2009 
IRC. As these caps do not increase stringency of the code (but rather 
restrict trade-off options), there is no direct impact on annual energy 
consumption or cost. There may, however, be some impacts on occupant 
comfort and/or resistance to moisture condensation, either of which 
could possibly induce occupants to increase energy consumption, for 
example by raising thermostat set points.
    2. The air barrier and insulation inspection requirements differ 
slightly between the codes. The 2009 IECC requires checking that ``Air-
permeable

[[Page 42699]]

insulation is inside of an air barrier'' (right column in the first 
row). The 2009 IRC is missing this, which could result in insulation on 
the exterior side of an air barrier being exposed to wind-induced air 
movement that reduces its effective R-value.
    3. The definitions of ``conditioned space'' are different between 
the two codes, which, depending on local officials' interpretations, 
could result in different portions of a building being deemed 
conditioned and hence subject to the code's envelope requirements.
    4. The three labels ``mandatory,'' ``prescriptive,'' and 
``performance'' are used to label many sections in the 2009 IECC, but 
are not used at all in the 2009 IRC. The provisions that are mandatory 
are always required while prescriptive provisions can be traded off as 
long as overall home energy efficiency is not decreased. Thus the 2009 
IRC may permit trading down the efficiency of some components with the 
potential to induce increased energy consumption as described above.
    5. The 2009 IRC (section N1101.1, ``Scope'') states that chapter 11 
(Energy Efficiency) does not apply to portions of the building envelope 
that do not enclose conditioned space. Section 101.5.2 of the IECC is 
more specific, exempting only building thermal envelope provisions that 
do not contain conditioned space.

B. Impact of the Differences Between the 2009 IRC and 2009 IECC

    DOE has performed a limited analysis of potential impact of the 
differences between the 2009 IECC and 2009 IRC. The analysis involves 
thermal simulation of home performance in several representative 
locations using the EnergyGauge (DOE-2) \13\ simulation tool on a 
typical house:
---------------------------------------------------------------------------

    \13\ EnergyGauge is available at http://doe2.com/.
---------------------------------------------------------------------------

     2400 ft\2\ floor area, two-story.
     Natural gas furnace heating at $1.20/therm.
     Central air conditioning electricity at 12 cents/kWh.
     Equipment efficiencies at Federal minimum levels.
     360 ft\2\ window area equally distributed to the north, 
east, south, and west building faces, with no exterior shading.
    The results are shown in Tables 8 through 10. The 2009 IRC yields a 
higher annual energy cost in almost all cases.

          Table 8--Energy Savings of Reducing SHGC From 0.35 to 0.30 in Climate Zones One Through Three
----------------------------------------------------------------------------------------------------------------
                                                                             Cooling      Heating       Energy
               Climate zone                      Representative city         savings      increase     savings
----------------------------------------------------------------------------------------------------------------
1.........................................  Miami........................          $29           $0          $29
2.........................................  Houston......................           18            9            9
2.........................................  Phoenix......................           20            1           19
3.........................................  Atlanta......................           16           18           -2
3.........................................  Jackson MS...................           19           15            4
3.........................................  Memphis......................           17           17            0
3.........................................  Dallas.......................           20           14            6
3.........................................  El Paso......................           18           17            1
3.........................................  Las Vegas....................           16           15            1
----------------------------------------------------------------------------------------------------------------

Table 9--Energy Savings of Increasing Basement Wall Insulation From R-13
               to R-19 in Climate Zones Six Through Eight
------------------------------------------------------------------------
                                                                Energy
            Climate zone               Representative city     savings
------------------------------------------------------------------------
6..................................  Burlington............          $29
7..................................  Duluth................           34
8..................................  Fairbanks.............           33
------------------------------------------------------------------------

 Table 10--Energy Savings of Increasing Floor Insulation From R-30 to R-
   38 in Climate Zones Seven and Eight (Floor Over Unheated Basement)
------------------------------------------------------------------------
                                                                Energy
            Climate zone               Representative city     savings
------------------------------------------------------------------------
7..................................  Duluth................           13
8..................................  Fairbanks.............           19
------------------------------------------------------------------------

IV. Filing Certification Statements With DOE

A. State Determinations

    Upon publication of this final determination, each State is 
required to determine the appropriateness of revising the portion of 
its residential building code regarding energy efficiency to meet or 
exceed the provisions of the ICC IECC, 2009 edition. (42 U.S.C. 
6833(a)(5)(B)) A State determination for the 2009 IECC would be 
sufficient to address all of the DOE determinations (e.g. 2006 and 
2003) in this notice. The State determination must be: (1) Made after 
public notice and hearing; (2) in writing; (3) based upon findings and 
upon the evidence presented at the hearing; and (4) made available to 
the public. States have considerable discretion with regard to the 
hearing procedures they use, subject to providing an adequate 
opportunity for members of the public to be heard and to present 
relevant information. The Department recommends publication of any 
notice of public hearing in a newspaper of general circulation and 
online. The determinations are required to be made not later than two 
years from the date of publication of this notice of final 
determination, unless an extension is provided (see section B. below 
for more details).
    Note that the applicability of any State revisions to new or 
existing buildings would be governed by the State building codes. 
However, it is our understanding that generally, the revisions would 
not apply to existing buildings unless they are undergoing a change 
that requires a building permit.
    States should be aware that the Department considers high-rise 
(greater than three stories) multifamily residential buildings and 
hotel, motel, and other transient residential building types of any 
height as commercial buildings for energy code purposes. Residential 
buildings include one- and two-family detached and attached buildings, 
duplexes, townhouses, row houses, and low-rise multifamily buildings 
(not greater than three stories) such as condominiums and garden 
apartments.
    States should also be aware that the determinations do not apply to 
Chapter 5 of the 2009 IECC, which addresses commercial buildings as 
defined above. Therefore, States must certify their evaluations of 
their State building codes for residential buildings with respect to 
all provisions of the IECC except for that chapter.
    Section 304(a)(4) of ECPA, as amended, requires that if a State 
makes a determination that it is not

[[Page 42700]]

appropriate to revise the energy efficiency provisions of its 
residential building code, the State must submit to the Secretary, in 
writing, the reasons for this determination and the statement shall be 
available to the public. (42 U.S.C. 6833(a)(4))
    Some States develop their own codes that are only loosely related 
to the national model codes and DOE does not typically provide 
technical support for those codes. However, DOE does provide grants to 
these States through grant programs administered by the National Energy 
Technology Laboratory (NETL). DOE does not prescribe how each State 
adopts and enforces its energy codes.

B. Requests for Extensions To Certify

    Section 304(c) of ECPA, as amended, requires that the Secretary 
permit an extension of the deadline for complying with the 
certification requirements described above, if a State can demonstrate 
that it has made a good faith effort to comply with such requirements 
and that it has made significant progress toward meeting its 
certification obligations. (42 U.S.C. 6833(c)) Such demonstrations 
could include one or both of the following: (1) A plan for response to 
the requirements stated in Section 304; and/or (2) a statement that the 
State has appropriated or requested funds (within State funding 
procedures) to implement a plan that would respond to the requirements 
of Section 304 of ECPA. This list is not exhaustive.

V. Regulatory Analysis

A. Review Under Executive Order 12866

    Today's action is a significant regulatory action under section 
3(f)(1) of Executive Order 12866, ``Regulatory Planning and Review'' 
(58 FR 51735 (Oct. 4, 1993)). Accordingly, today's action was reviewed 
by the Office of Information and Regulatory Affairs (OIRA) in the 
Office of Management and Budget (OMB).

B. Review Under the Regulatory Flexibility Act

    The Regulatory Flexibility Act (5 U.S.C. 601 et seq.) requires the 
preparation of an initial regulatory flexibility analysis for any rule 
that by law must be proposed for public comment, unless the agency 
certifies that the rule, if promulgated, will not have a significant 
economic impact on a substantial number of small entities. As required 
by Executive Order 13272, ``Proper Consideration of Small Entities in 
Agency Rulemaking,'' (67 FR 53461 (Aug. 16, 2002)), DOE published 
procedures and policies on February 19, 2003, to ensure that the 
potential impacts of its rules on small entities are properly 
considered during the rulemaking process (68 FR 7990). DOE has made its 
procedures and policies available on the Office of General Counsel's 
Web site: http://www.gc.doe.gov.
    DOE has reviewed today's rule under the provisions of the 
Regulatory Flexibility Act and the procedures and policies published on 
February 19, 2003. Today's final determination of improved energy 
efficiency between IECC editions requires States to undertake an 
analysis of their respective building codes. As such, the only entities 
directly regulated by this rulemaking would be States. DOE does not 
believe that there will be any direct impacts on small entities such as 
small businesses, small organizations, or small governmental 
jurisdictions.
    On the basis of the foregoing, DOE certifies that the rule would 
not have a significant economic impact on a substantial number of small 
entities. Accordingly, DOE has not prepared a regulatory flexibility 
analysis for this rulemaking. DOE's certification and supporting 
statement of factual basis will be provided to the Chief Counsel for 
Advocacy of the Small Business Administration pursuant to 5 U.S.C. 
605(b).

C. Review Under the National Environmental Policy Act of 1969

    DOE has determined that today's action is covered under the 
Categorical Exclusion found in DOE's National Environmental Policy Act 
regulations at paragraph A.6. of Appendix A to subpart D, 10 CFR part 
1021. That Categorical Exclusion applies to actions that are strictly 
procedural, such as rulemaking establishing the administration of 
grants. Today's action impacts whether States must perform an 
evaluation of State building codes. The action would not have direct 
environmental impacts. Accordingly, DOE has not prepared an 
environmental assessment or an environmental impact statement.

D. Review Under Executive Order 13132, ``Federalism''

    Executive Order 13132, 64 FR 43255 (Aug. 4, 1999), imposes certain 
requirements on agencies formulating and implementing policies or 
regulations that pre-empt State law or that have federalism 
implications. Agencies are required to examine the constitutional and 
statutory authority supporting any action that would limit the 
policymaking discretion of the States and carefully assess the 
necessity for such actions. DOE has examined today's final rule and has 
determined that it will not pre-empt State law and will not have a 
substantial direct effect on the States, on the relationship between 
the national government and the States, or on the distribution of power 
and responsibilities among the various levels of government. Pursuant 
to Section 304(a) of ECPA, DOE is statutorily required to determine 
whether the most recent version of the 1992 Model Energy Code (MEC), or 
any successor to that code, would improve the level of energy 
efficiency in residential buildings compared to the previous version. 
If DOE makes a positive determination, the statute requires each State 
to certify that it has compared its residential building code regarding 
energy efficiency to the revised code and made a determination whether 
it is appropriate to revise its code to meet or exceed the provisions 
of the successor code. (42 U.S.C. 6833(a)(5)(B)) Therefore, today's 
action only impacts whether States must perform an evaluation of State 
building codes. No further action is required by Executive Order 13132.

F. Review Under the Unfunded Mandates Reform Act of 1995

    The Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4) generally 
requires Federal agencies to examine closely the impacts of regulatory 
actions on State, local, and tribal governments. Subsection 101(5) of 
Title I of that law defines a Federal intergovernmental mandate to 
include any regulation that would impose upon State, local, or tribal 
governments an enforceable duty, except a condition of Federal 
assistance or a duty arising from participating in a voluntary Federal 
program. Title II of that law requires each Federal agency to assess 
the effects of Federal regulatory actions on State, local, and tribal 
governments, in the aggregate, or to the private sector, other than to 
the extent such actions merely incorporate requirements specifically 
set forth in a statute. Section 202 of that title requires a Federal 
agency to perform a detailed assessment of the anticipated costs and 
benefits of any rule that includes a Federal mandate which may result 
in costs to State, local, or tribal governments, or to the private 
sector, of $100 million or more. Section 204 of that title requires 
each agency that proposes a rule containing a significant Federal 
intergovernmental mandate to develop an effective process for obtaining 
meaningful and timely input from elected officers of State, local, and 
tribal governments.

[[Page 42701]]

    Today's action impacts whether States must perform an evaluation of 
State building codes. Today's action would not impose a Federal mandate 
on State, local or tribal governments, and it would not result in the 
expenditure by State, local, and tribal governments in the aggregate, 
or by the private sector, of $100 million or more in any one year. 
Accordingly, no assessment or analysis is required under the Unfunded 
Mandates Reform Act of 1995.

G. Review Under the Treasury and General Government Appropriations Act 
of 1999

    Section 654 of the Treasury and General Government Appropriations 
Act of 1999 (Pub. L. 105-277) requires Federal agencies to issue a 
Family Policymaking Assessment for any rule that may affect family 
well-being. Today's action would not have any impact on the autonomy or 
integrity of the family as an institution. Accordingly, DOE has 
concluded that it is not necessary to prepare a Family Policymaking 
Assessment.

H. Review Under the Treasury and General Government Appropriations Act 
of 2001

    Section 515 of the Treasury and General Government Appropriations 
Act, 2001 (44 U.S.C. 3516, note) provides for agencies to review most 
disseminations of information to the public under guidelines 
established by each agency pursuant to general guidelines issued by 
OMB. OMB's guidelines were published at 67 FR 8452 (Feb. 22, 2002), and 
DOE's guidelines were published at 67 FR 62446 (Oct. 7, 2002). DOE has 
reviewed today's action under the OMB and DOE guidelines and has 
concluded that it is consistent with applicable policies in those 
guidelines.

I. Review Under Executive Order 13211

    Executive Order 13211, ''Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use,'' 66 FR 28355 
(May 22, 2001), requires Federal agencies to prepare and submit to the 
OMB a Statement of Energy Effects for any proposed significant energy 
action. A ``significant energy action'' is defined as any action by an 
agency that promulgated or is expected to lead to promulgation of a 
final rule, and that: (1) Is a significant regulatory action under 
Executive Order 12866, or any successor order; and (2) is likely to 
have a significant adverse effect on the supply, distribution, or use 
of energy, or (3) is designated by the Administrator of the Office of 
Information and Regulatory Affairs (OIRA) as a significant energy 
action. For any proposed significant energy action, the agency must 
give a detailed statement of any adverse effects on energy supply, 
distribution, or use, should the proposal be implemented, and of 
reasonable alternatives to the action and their expected benefits on 
energy supply, distribution, and use.
    Today's action would not have a significant adverse effect on the 
supply, distribution, or use of energy and is therefore not a 
significant energy action. Accordingly, DOE has not prepared a 
Statement of Energy Effects.

J. Review Under Executive Order 13175

    Executive Order 13175. ``Consultation and Coordination with Indian 
Tribal Governments'' (65 FR 67249 (Nov. 9, 2000)), requires DOE to 
develop an accountable process to ensure ``meaningful and timely input 
by tribal officials in the development of regulatory policies that have 
tribal implications.'' ``Policies that have tribal implications'' 
refers to regulations that have ``substantial direct effects on one or 
more Indian tribes, on the relationship between the Federal Government 
and Indian tribes, or on the distribution of power and responsibilities 
between the Federal Government and Indian tribes.'' Today's regulatory 
action is not a policy that has ``tribal implications'' under Executive 
Order 13175. DOE has reviewed today's action under executive Order 
13175 and has determined that it is consistent with applicable policies 
of that Executive Order.

    Issued in Washington, DC, on July 13, 2011.
Kathleen Hogan,
Deputy Assistant Secretary for Energy Efficiency, Office of Technology 
Development, Energy Efficiency and Renewable Energy.
[FR Doc. 2011-18080 Filed 7-18-11; 8:45 am]
BILLING CODE 6450-01-P
```