The Design Energy Code is an input in the Extended Project Info section. For whole building projects that are not energy modeled, the Design Energy Code selection determines the estimated savings for the project. The savings percent is a code equivalent percent savings of the selected code to the basis for the 2030 Challenge (CBECS 2003).
The Design Energy Code Equivalent Percentage Savings values are based on a collaboration with New Buildings Institute, which utilizes the code determination analysis by Pacific Northwest National Laboratory (PNNL) for each new version of ASHRAE Standard 90.1 to establish zEPI scores that ultimately become the code equivalent savings (100 - zEPI).
The DDx Design Energy Code Equivalent Percentage Savings can vary over time, due to one or more of the following reasons:
- Significant new research has been made available; for example, when ASHRAE started using 90.1-2004 as the baseline for their calculations to assist making new versions and versions of other codes comparable to a single version. Leading up to this shift, additional research and analysis were completed to assess what the percentage savings between 90.1-2004 and CBECS 2003 (baseline for 2030 Challenge) should be. The resulting adjustment had a ripple effect across a number of design energy codes, and the update has now been incorporated into the DDx.
- There could be a difference between the pre-publication and final determination of percent savings. The timing of the PNNL final determination can vary, but they tend to issue a pre-publication notice near the release of a new ASHRAE version. The pre-publication value will be associated with the design energy code initially, and it will be updated as needed after the final determination has been published.
- Additional research and analysis has been provided to AIA for regional and/or international codes that warrant an update of the value. Changes to the code equivalencies will only be updated at the point of saving and will not get updated across projects unless the projects are re-saved.
If the project’s design energy code is not available in the dropdown list, it is recommended to use the closest design energy code in vintage to the project’s code, in the interim until the Design Energy Code Equivalent Percentage Savings is shared with AIA. (For example, if California Title 24-2022 is the project’s design energy code, but that version is not available in the DDx dropdown yet, use the most recent vintage: California Title 24-2019. The tool will allow updates to the project’s energy code once it is available.)
Design Energy Code Percent Reduction vs. Modeled pEUI Percent Reduction
- If using code equivalent savings, the selected design energy code will drive the percent savings.
- If a project has an energy model, the percent savings is derived from the pEUI and the baseline EUI.
- If a project has an energy model, check to make sure the percent savings is a reasonable number – comparing to the code equivalent percent savings is a helpful benchmark.
- If the percent savings value is unexpected, reevaluate and consider adjusting the baseline EUI.
The table below details the approximate percent reduction based on the selected design energy codes.
Click here for the table...
Design Energy Code Equivalents |
Sector | Code | zEPI | % better than CBECS | Methodology | Data Source | Link |
Commercial | Older than 1999 |
| 0% | Defined as baseline |
|
|
Residential | Older than 1999 |
| 0% | Defined as baseline |
|
|
Commercial | 90.1-1999 | 84 | 16% | DOE/PNNL percent savings improvement over previous code | DOE Code Improvement Estimate Dashboard | Click here
|
Commercial | 90.1-2001 | 84 | 16% | DOE/PNNL percent savings improvement over previous code | DOE Code Improvement Estimate Dashboard | Click here
|
Commercial | 90.1-2004 | 75 | 25% | Set at 25% improvement or zEPI 75 | DOE Code Improvement Estimate Dashboard | Click here
|
Commercial | 90.1-2007 | 72 | 28% | DOE/PNNL percent savings improvement over previous code | DOE Code Improvement Estimate Dashboard | Click here |
Commercial | 90.1-2010 | 58 | 42% | DOE/PNNL percent savings improvement over previous code | DOE Code Improvement Estimate Dashboard | Click here |
Commercial | 90.1-2013 | 54 | 46% | DOE/PNNL percent savings improvement over previous code | DOE Code Improvement Estimate Dashboard | Click here |
Commercial | 90.1-2016 | 50 | 50% | DOE/PNNL percent savings improvement over previous code | DOE Code Improvement Estimate Dashboard | Click here |
Commercial | 90.1-2019 | 48 | 52% | DOE/PNNL percent savings improvement over previous code | DOE Code Improvement Estimate Dashboard | Click here |
Residential | 2003 IECC | 78 | 22% | DOE/PNNL percent savings improvement over previous code | DOE Code Improvement Estimate Dashboard | Click here |
Residential | 2006 IECC | 75 | 25% | Set at 25% improvement or zEPI 75 | DOE Code Improvement Estimate Dashboard | Click here |
Residential | 2009 IECC | 69 | 31% | DOE/PNNL percent savings improvement over previous code | DOE Code Improvement Estimate Dashboard | Click here |
Residential | 2012 IECC | 56 | 44% | DOE/PNNL percent savings improvement over previous code | DOE Code Improvement Estimate Dashboard | Click here |
Residential | 2015 IECC | 56 | 44% | DOE/PNNL percent savings improvement over previous code | DOE Code Improvement Estimate Dashboard | Click here |
Residential | 2018 IECC | 55 | 45% | DOE/PNNL percent savings improvement over previous code | DOE Code Improvement Estimate Dashboard | Click here |
Residential | 2021 IECC | 50 | 50% | DOE/PNNL percent savings improvement over previous code | DOE Code Improvement Estimate Dashboard | Click here |
| NECB 2011 |
| 45% | No Analysis Available | Page 39 | Click here |
| NECB 2015 |
| 51% | No Analysis Available |
|
|
| NECB 2017 |
| 55% | No Analysis Available |
| Click here |
Commercial | Oregon 2021 | 49 | 51% | Site Energy Index per PNNL Analysis | Commercial dashboard | Click here |
Residential | Oregon 2021 | 56 | 44% | Site Energy Index per PNNL Analysis | Residential Dashboard |
|
Commercial | Washington 2021 | 48 | 52% |
|
|
|
Residential | Washington 2021 | 51 | 49% | 2021 IECC Energy Index for WA. State code would likely be higher | PNNL State-level results spreadsheets | Click here |
Commercial | California Title 24 2019 | 50 | 50% | 90.1-2019 Energy Index for CA. T24 would likely be higher | PNNL State-level results spreadsheets | Click here |
Residential | California Title 24 2016 | 53 | 48% | 2021 IECC Energy Index for CA. T24 would likely be higher | PNNL State-level results spreadsheets | Click here |
Commercial | California Title 24 2022 |
| 81% |
|
|
|
Commercial | NYStretch 2018 | 48 | 52% | Percent energy savings over 90.1-2013 | PNNL/NBI Determination Analysis | Click here |
Commercial | Massachusetts Stretch Code 2017 | 45 | 55% | Ten percent improvement over base code energy index | Base code Energy Index per PNNL Analysis | Click here |
Commercial | Massachusetts Stretch Code 2020 | 42 | 58% | Ten percent improvement over base code energy index | Base code Energy Index per PNNL Analysis | Click here |
Commercial | ASHRAE 189.1-2020 | 46 | 54% | 5% better than 90.1-2019 - From targeted 5% improvement in Building Performance Factors (BPF) | ASHRAE Standard 189.1 Text |
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Note: These are estimates of code comparison based on analyses by Pacific Northwest National Laboratory, New Buildings Institute, and Architecture 2030. These percentages are provided to enable the inclusion of non-modeled projects in analysis for the AIA 2030 Commitment.
*Source for this code is from the National Research Council Canada. |