April 25, 2012

The U.S. Department of Energy (DOE) published a Request for Information (RFI) on Building Energy 

Codes Cost Analysis (Docket No. EERE-2011-BT-BC-0046)

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in the Federal Register on September 13, 

2011. (76 FR 56413.) The notice sought public input on how DOE may improve the methodology DOE 

intends to use for assessing cost-effectiveness (which includes an energy savings assessment) of changes 

to residential building energy codes. DOE supports the development of the International Code Council’s 

(ICC) International Energy Conservation Code (IECC), the national model code adopted by or forming the 

basis of residential energy codes promulgated by a majority of U.S. states, as well as other voluntary 

building energy codes. DOE performs a cost-effectiveness analysis of proposed modifications to the 

codes as part of that support. DOE also performs an analysis of cost-effectiveness of new code versions.2 

The RFI identified several specific areas for public comment. In response to the comments received, 

DOE revised the methodology by which DOE intends to assess quantitatively the energy efficiency and

cost-effectiveness of residential energy codes. DOE has modified the methodology in several areas to

improve overall energy and economic calculations. Careful consideration was given to each public 

comment. While many responses to comments are reflected in the cost analysis methodology, not all 

comments, including those beyond the scope of this request, could be accommodated. Significant 

changes can be summarized as follows:

Climate Locations: DOE originally proposed to use 15 climate locations in its analysis, 

representing the various code climate zones and moisture regimes. DOE is expanding the 

number and distribution of weather locations to include a set of 119 locations, providing more 

specific geographical coverage, and allowing aggregation directly from state-level results to both 

zonal and national averages.

Weather Data: The RFI proposed reference to revision 2 of Typical Meteorological Year data 

(TMY2) for its energy simulation analyses. DOE will use TMY3 data files, based on more recent 

record years than previous revisions.

Multi-family Prototype Building: The originally proposed methodology assumed a two-story 

multi-family building. Public comments indicated a three-story prototype may be more 

representative of the average multi-family building. The methodology was modified to 

accommodate this request.

Replacement of Efficiency Components: The originally proposed methodology made no explicit 

assumptions surrounding the replacement of features over the life of the analysis. DOE is 

expanding the methodology to account for these replacements through a like-for-like

assumption. Measures with a service life less than the overall analysis period will be assumed

replaced with products of identical efficiency. 

 

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Federal Register Docket: http://www.regulations.gov/#!documentDetail;D=EERE-2011-BT-BC-0046-0001 

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Additionally, DOE is statutorily required to evaluate whether updates to the IECC would result in increased energy 

savings as compared to the prior version. (42 U.S.C. 6833(a)(5)(A)) The statutorily required determination is based 

solely on an assessment of energy savings. To the extent a quantitative analysis would be required for such a 

determination, DOE would rely on the energy savings portion of the methodology.
Mortgage Insurance: The RFI did not include the expense of mortgage insurance. Comments 

indicated this type of insurance may be required when less than a 20% down payment is 

applied. As the methodology proposed only a 10% down payment, a modification was made to 

include this insurance expense within the calculation.

The DOE methodology is based on a life-cycle economic assessment over the life of the building. The

assessment will also analyze cash flows and payback periods from the homeowner perspective, in 

addition to an estimate of energy savings. DOE intends to use this methodology to evaluate impacts of 

existing codes, as well as in proposing future code changes. National analyses will include an estimate of 

energy savings. In addition, state and zonal analyses will include the economic assessment. The DOE 

methodology will also be updated over time to accommodate significant changes, such as shifting 

economic conditions and the availability of newer data sources.

The residential cost analysis methodology is available on DOE’s energy codes website3. Applications of 

the method are expected to be posted in the following weeks, including assessments of the 2009 and 

2012 editions of the IECC, followed by ongoing concepts DOE is investigating for potential in the 2015 

IECC code cycle.

For additional information or questions, please to contact Michael Erbesfeld

(michael.erbesfeld@ee.doe.gov, (202) 287-1874). 

Building Energy Codes

U.S. Department of Energy

 

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DOE Building Energy Codes website: http://www.energycodes.gov/development/residential