Determination Regarding Energy Efficiency Improvements in the 2015 International Energy Conservation Code (IECC)
A. Statutory Authority
Title III of the Energy Conservation and Production Act (ECPA), as amended, establishes requirements for building energy conservation standards, administered by the DOE Building Energy Codes Program. (42 U.S.C. 6831 et seq.) Section 304(a), as amended, of ECPA provides that whenever the 1992 Model Energy Code (MEC), or any successor to that code, is revised, the Secretary of Energy (Secretary) must make a determination, not later than 12 months after such revision, whether the revised code would improve energy efficiency in residential buildings, and must publish notice of such determination in the Federal Register. (42 U.S.C. 6833(a)(5)(A)) The Secretary may determine that the revision of the 1992 MEC, or any successor thereof, improves the level of energy efficiency in residential buildings. If so, then not later than two years after the date of the publication of such affirmative determination, each State is required to certify that it has reviewed its residential building code regarding energy efficiency, and made a determination as to 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)(2)) 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)(4))
ECPA requires the Secretary to permit extensions of the deadlines for the State certification if a State can demonstrate that it has made a good faith effort to comply with the requirements of section 304(a) of ECPA, and that it has made significant progress in doing so. (42 U.S.C. 6833(c)) DOE is also directed to provide technical assistance to States to support implementation of State residential and commercial building energy efficiency codes. (42 U.S.C. 6833(d))
The International Energy Conservation Code (IECC) is the national model code establishing energy efficiency requirements for residential buildings. The IECC is revised every 3 years through a code development and consensus process administered by the International Code Council (ICC)
. Code change proposals may be submitted by any interested party, and are evaluated through a series of public hearings. As part of the ICC process, any interested party may submit proposals, as well as written comments or suggested changes to any proposal, and make arguments before a committee of experts assembled by the ICC. At the final public hearing, arguments are presented to and voted upon by the ICC Governmental Member Representatives, with the collection of accepted proposals forming the revised edition of the IECC. The ICC published the 2015 edition of the IECC (2015 IECC or 2015 edition) on June 3, 2014, which forms the basis of this determination notice.
In arriving at its determination, DOE reviewed all changes between the 2012 and 2015 editions of the IECC with respect to residential buildings. Accordingly, DOE published a Notice of Preliminary Determination regarding the 2015 IECC in the Federal Register on September 26, 2014 (79 FR 57915).
C. Public Comments Regarding the Determination
DOE accepted public comments on the Notice of Preliminary Determination for the 2015 IECC until October 27, 2014. DOE received timely submissions from a total of five submitters.
ICC’s first comment offers general support for DOE’s preliminary determination. (ICC, No. 2 at p. 2)2
In its second comment, ICC suggests DOE accompany its 2015 IECC determination with “previously released information regarding the increased efficiency of the 2012 IECC over the 2009 version, and the increased efficiency of the 2009 version over the 2006 version, in order to make it abundantly clear that the efficiency of the 2015 IECC is much higher than versions of the IECC in use in many states and jurisdictions around the nation.” (ICC, No. 2 at p. 2-3) DOE agrees with ICC’s assessment that the provisions of the 2015 edition of the IECC are much more energy efficient than several earlier editions of the model code. In performing its determination, DOE evaluates the expected national impact of the new edition of the model code, in this case the 2015 IECC, against the most recent previous edition receiving an affirmative determination of energy savings, in this case the 2012 IECC (42 U.S.C. 6833(a)(5)(A)). However, DOE recognizes that the updated code represents a significant savings opportunity—in many cases up to 30 percent savings relative to codes currently adopted by U.S. states.
In response, DOE has added references to earlier determinations, as well as the associated energy savings estimates, in Section V of this notice. In its third comment, ICC suggests DOE “emphasize that states are to compare the provisions of their current codes with the provisions and requirements of the 2015 IECC, and not assume that the percentage increase in efficiency for their respective state will be the same as the 1% increase measured by DOE over the provisions in the 2012 IECC.” (ICC, No. 2 at p. 3) DOE acknowledges that States and localities should indeed consider the impact of updated model codes relative to the specific requirements in effect within the state or locality. In performing its determination, DOE evaluates the updated model code relative to the previous model code, and estimates the aggregate impact on national energy consumption. As many adopting states and localities make modifications to the model code, these entities should evaluate the impacts of the updated code relative to their own
NAHB’s first comment suggests that “DOE’s analysis of the pipe insulation was not properly calculated” and noted that the actual net change made by this proposal was to increase the length of3/4-inch pipe requiring insulation by including runs shorter than 10 feet, while eliminating insulation requirements on smaller diameter piping. NAHB suggests “by properly applying the new hot water pipe insulation requirements, the resulting energy savings will change.” (NAHB, No. 3 at p. 1) DOE agrees with NAHB’s comments relative to the net energy savings surrounding this particular proposal, and has revised its analysis accordingly. The revised estimated total energy cost savings compared to the 2012 IECC are now 0.73% compared to the preliminary estimate of 0.90% (see
Section III of this notice). NAHB’s second comment notes that the “International Code Council (ICC) originally had proposal RE112-13 listed as being approved to be included in the 2015 edition of the IECC. This proposal, however, was actually withdrawn by the proponent before it was approved on the consent agenda. As a result, the changes were not included in the 2015 IECC and thus, any reference to RE112-13 should be removed from the analysis.” (NAHB, No. 3 at p. 2) DOE agrees with NAHB’s comment and acknowledges that the subject proposal is not included in the 2015 IECC. DOE notes that the original documentation published by the ICC following the public hearing process inadvertently included this proposal, and it has since been confirmed that the proposal was withdrawn from consideration during the hearing process. DOE has revised this notice and supporting documentation accordingly. (Note that RECA offered a similar comment on RE112-13; see RECA, No. 4 at p. 3.)
RECA’s first comment expresses general support for DOE’s Preliminary Determination on the 2015 edition of IECC, DOE’s evaluation methodology in both its quantitative and qualitative aspects, and DOE’s conclusion that the 2015 IECC’s weakening amendments are outweighed by its strengthening amendments. (RECA No. 4 at p. 1) In its second comment, RECA “urges the Department to move ahead to finalize its Determination endorsing the 2015 IECC for state adoption”; “to continue to provide materials to states and localities that will facilitate the adoption of, and compliance with, this latest edition of the IECC”; “to expeditiously make training and compliance software available to states that adopt the 2015 IECC”; and “to provide additional funding to those states that are early adopters of the 2015 IECC.” (RECA No. 4 at p. 1, and 3) DOE acknowledges the need for materials that can assist in facilitating the adoption of the latest editions of the model code. While these activities are not directly within the scope of the DOE determination analysis, DOE is directed to provide technical assistance to states implementing building energy codes (42 U.S.C. 6833(d)), and does so through a variety of activities, such as state-specific energy and cost analysis, code compliance software, and a collection of technical resources. DOE intends to continue to provide such resources to assist states in implementing updated model codes, including adoption of such codes by states and localities, and increasing compliance with building energy codes to ensure intended consumer energy and cost savings. In its third comment, RECA agrees with DOE that, “proposal RE68-13 slightly weakens sunroom fenestration requirements”, “the impact should be very small”, and it, “does not affect SHGC requirements”, but notes that “the impact is on climate zones 2-3, not climate zone 1.” (RECA No. 4 at p. 2) DOE agrees with RECA’s comment and assessment of the subject proposal, and has revised the determination notice and supporting analysis accordingly. In its fourth comment, RECA disagrees with DOE that duct tightness levels tend to always be a “zero sum trade-off” as claimed in the Preliminary Determination, and suggests that “the Department explicitly and correctly recognize the value of mandatory measures, and that removal of this mandatory backstop is a reduction in stringency in some cases, albeit likely modest, depending on the measure that replaces duct efficiency.” (RECA No. 4 at p. 2-3) DOE agrees in principle with RECA’s comment that energy neutrality depends on a variety of factors, including impacts over the useful life of alternative energy measures. In the case of building energy efficiency tradeoffs, the impact on longer-term energy savings can vary significantly between the measures being traded and the chosen alternative designs. In addition, DOE understands the purpose of mandatory requirements within the code, and while the subject proposal cannot directly be captured within the DOE quantitative analysis, DOE indeed acknowledges the potential effect on building energy efficiency in application. In its fifth comment, RECA notes that proposal RE112-13 “was withdrawn prior to final consideration, and is thus not part of the 2015 IECC.” (RECA No. 4 at p. 3) DOE agrees with this comment, as detailed above in response to NAHB’s similar comment. In its sixth comment, RECA suggests that DOE should “continue to assess the potential impact of changes to the IECC for compliance paths outside the prescriptive path” averring that expanding the Department’s ability to further assess such changes is in the public interest. (RECA No. 4 at p. 3) With specific reference to DOE’s evaluation of the new ERI compliance path, RECA agrees with DOE’s use of the prescriptive compliance path as the generally predominant path, but recommends “this emphasis on the prescriptive path for the numerical analysis should not be read as limiting the overall assessment of all changes in the code, nor should it suggest that an edition of the code will receive a positive or negative determination solely on the basis of this quantitative analysis.” RECA notes that in previous determinations, DOE has not historically limited itself to analyzing only changes to the prescriptive path, and encourages DOE not to limit itself to only considering changes to the prescriptive path in the future. RECA “urges the Department to clarify in its Determination that it will continue to assess any changes made to the performance path, and any new compliance options (like ERI) that are added to the IECC going forward in future Determinations.” DOE agrees with RECA’s comment in principle, and acknowledges that changes in the 2015 IECC, as well as potential future changes to the IECC, are likely to require increasingly nuanced analyses of the changes’ impacts. As stated in the preliminary notice, DOE plans to collect data specifically on the ERI path, and will consider means to broaden the scope of that commitment, as necessary, in the future. In addition, while the DOE Determination has typically focused on the mandatory and prescriptive requirements of the IECC, the Department reserves the right to evaluate other means of compliance when adequate information is available. In its seventh comment, RECA agrees with DOE that “it is difficult to assess the impact of the new Energy Rating Index in the context of a Determination,” but argues that “DOE could reasonably conclude, based on the results of a Pacific Northwest National Laboratory study, that the new compliance path is reasonably likely to save energy as compared to compliance with the 2012 IECC prescriptive requirements on average, even if some individual homes could be weaker than those built to the 2012 IECC.”
(RECA No. 4 at p. 5) DOE appreciates the comment and agrees, based on the referenced PNNL analysis, that most homes built using the ERI path, as specified in the 2015 IECC, are likely to be at least as efficient as the homes built to meet the prescriptive requirements of the IECC or the traditional performance path. In its eighth comment, RECA urges DOE to “promote the proper adoption and implementation of the ERI as contained in the 2015 IECC, without any weakening amendments, including monitoring its deployment in states and cities going forward.” RECA also recommends “DOE develop and/or fund comprehensive support materials and training to help to ensure that the ERI is properly implemented,” and that “DOE should also consider how it can help to ensure that the ERI process produces consistent, repeatable, and credible results for code compliance.” (RECA No. 4 at p. 5-7) DOE acknowledges the importance of the new ERI path in the 2015 IECC and its potential impact on energy as the code is implemented. While code implementation activities are outside the direct scope of the DOE determination, DOE does provide technical assistance to states implementing building energy codes (42 U.S.C. 6833(d)). DOE recognizes the need for continued analysis and support for states adopting the 2015 IECC, and will consider the requested activities, as able and appropriate, through the Building Energy Codes Program. In its ninth comment, RECA supports the “Department’s stated plan to collect data relevant to the ERI, as well as all compliance options allowed in the IECC.” RECA further encourages the Department to “reach out to industry and nonprofit partners to aggregate the data already available, and to explore new methods for collecting and analyzing data on the various compliance options and tools used across the country.” (RECA No. 4 at p. 7) DOE acknowledges and appreciates RECA’s support, and plans to work with the industry and stakeholders in evaluating the new ERI path and associated energy impact. As previously stated, DOE intends to collect relevant data and track the implementation of the ERI path relative to the traditional compliance options provided by the IECC. DOE will continue to communicate with interested and affected parties as the 2015 IECC is implemented and as further data and resulting analysis becomes available.
NRDC’s first two comments offer general support for DOE’s determination that the 2015 IECC saves energy compared to the 2012 IECC, for DOE’s quantitative finding of energy savings, and for DOE’s qualitative assessment of the specific code changes that will result in energy savings. (NRDC, No. 5 at p. 1-2) In its third comment NRDC suggests that “actual energy savings from the 2015 IECC are likely to be much larger than indicated by DOE’s analysis”, specifically suggesting that the “new Energy Rating Index (ERI) pathway created by RE188-13 is likely to result in significant energy savings.” (NRDC, No.5 at p.2) NRDC acknowledges that it is not knowable exactly how many homes will comply using the ERI pathway, but suggests it is certainly not zero. NRDC suggests that “currently about half of new homes constructed in the U.S. are rated using the RESNET HERS rating”, and that “it is likely a large percentage of these homes will choose to comply with the code via the ERI pathway, since this will likely be the simplest method of compliance.” (NRDC, No. 5 at p. 2) NRDC further notes that a “Pacific Northwest National Laboratory analysis of the HERS index’s relationship to the 2012 IECC performance path found that for all climate zones the ERI values adopted in the 2015 IECC ranged from at least as efficient to substantially more efficient than the 2012 IECC, indicating that homes complying with the ERI path will on average achieve large energy savings compared to the 2012 IECC.” (NRDC, No. 5 at p. 2) DOE agrees that the new alternative ERI compliance path, including the associated thresholds as published in the 2015 IECC, is reasonably likely to result in energy savings compared to the 2012 IECC and the majority of current state codes. However, DOE remains unaware of any current data source that would allow for adequate evaluation of the newly created path. DOE continues to base its evaluation of the new path on the recent analysis conducted by PNNL, as referenced in the preliminary determination notice. In its fourth comment, NRDC appreciates DOE’s indication in the preliminary determination that “it will attempt to collect data on the utilization of the various compliance pathways and evaluate whether it can quantify savings from compliance pathways other than the prescriptive path in future determinations”, and urges DOE to “evaluate energy savings from the ERI pathway in future determinations, as currently the analysis leaves out this potential source of significant energy savings.” (NRDC, No. 5 at p.2) DOE acknowledges the importance of evaluating the energy impact of the ERI alternative, but remains unaware of any current data source that would allow for adequate evaluation of the newly created path. DOE, therefore, maintains its intentions to track the adoption of the ERI path relative to traditional application of the IECC, and may further evaluate this path in future analyses.
One comment was received from an individual submitter, Craig Conner, who indicated that “DOE made errors in estimating the residential energy savings for the change that included a new tropical option for residential construction (CE66-13 Part II, or CE66-II).” (Conner No. 6 at p. 1) Mr. Conner suggests that “DOE modeling was not done in accordance with the IECC standard reference design, and therefore is not as required for a determination.” He further suggests that “several major energy saving requirements provided by this new option were ignored or underestimated”, and argues that “the definition of the Tropical Zone, which is a subset of existing IECC Climate Zone 1, does not by itself increase or decrease energy”, but that “it is the associated requirements that would potentially affect energy use.” (Conner No. 6 at p. 1) Mr. Conner cites three aspects of proposal CE66-13 Part II that should have been considered new energy-saving requirements rather than conditions under which other requirements may be lessened, as DOE interpreted them: The restriction that the home not be heated and that 50% of the home be uncooled, the restriction that 80% of domestic water heating be by solar or other renewable sources, and the restriction that natural ventilation be facilitated by operable windows. (Conner No. 6 at p. 1) In response, DOE appreciates Mr. Conner’s comments, but does not agree with his assessment regarding the particular proposal. The IECC Standard Reference Design (SRD) is intended for demonstrating compliance of individual buildings, which differs from the aggregate national analysis applied in DOE determinations. Although the DOE building modeling prototypes and simulation methodology occasionally draw on SRD assumptions, where appropriate, they are also informed by additional sources that may better represent typical construction practices, and to estimate an expected impact of code changes. In this case, DOE considered typical construction affected by the newly defined Tropical Zone, and acknowledges the modified criteria associated with partially-conditioned homes (e.g., with solar water heating systems and operable windows). However, it is not clear that these changes will encourage additional use of energy-saving features, and DOE has maintained its original assessment.