Add Design Energy Code

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
SectorCodezEPI% better than CBECSMethodologyData SourceLink
CommercialOlder than 1999
0%Defined as baseline

ResidentialOlder than 1999
0%Defined as baseline

Commercial90.1-19998416%DOE/PNNL percent savings improvement over previous codeDOE Code Improvement Estimate Dashboard

Click here


Commercial90.1-20018416%DOE/PNNL percent savings improvement over previous codeDOE Code Improvement Estimate Dashboard

Click here


Commercial90.1-20047525%Set at 25% improvement or zEPI 75DOE Code Improvement Estimate Dashboard

Click here


Commercial90.1-20077228%DOE/PNNL percent savings improvement over previous codeDOE Code Improvement Estimate DashboardClick here
Commercial90.1-20105842%DOE/PNNL percent savings improvement over previous codeDOE Code Improvement Estimate Dashboard

Click here

Commercial90.1-20135446%DOE/PNNL percent savings improvement over previous codeDOE Code Improvement Estimate DashboardClick here
Commercial90.1-20165050%DOE/PNNL percent savings improvement over previous codeDOE Code Improvement Estimate DashboardClick here
Commercial90.1-20194852%DOE/PNNL percent savings improvement over previous codeDOE Code Improvement Estimate DashboardClick here
Residential2003 IECC7822%DOE/PNNL percent savings improvement over previous codeDOE Code Improvement Estimate DashboardClick here
Residential2006 IECC7525%Set at 25% improvement or zEPI 75DOE Code Improvement Estimate DashboardClick here
Residential2009 IECC6931%DOE/PNNL percent savings improvement over previous codeDOE Code Improvement Estimate DashboardClick here
Residential2012 IECC5644%DOE/PNNL percent savings improvement over previous codeDOE Code Improvement Estimate DashboardClick here
Residential2015 IECC5644%DOE/PNNL percent savings improvement over previous codeDOE Code Improvement Estimate DashboardClick here
Residential2018 IECC5545%DOE/PNNL percent savings improvement over previous codeDOE Code Improvement Estimate DashboardClick here
Residential2021 IECC5050%DOE/PNNL percent savings improvement over previous codeDOE Code Improvement Estimate DashboardClick here

NECB 2011
45%No Analysis AvailablePage 39Click here

NECB 2015
51%No Analysis Available


NECB 2017
55%No Analysis Available
Click here
CommercialOregon 20214951%Site Energy Index per PNNL AnalysisCommercial dashboardClick here
ResidentialOregon 20215644%Site Energy Index per PNNL AnalysisResidential Dashboard
CommercialWashington 20214852%


ResidentialWashington 20215149%2021 IECC Energy Index for WA. State code would likely be higherPNNL State-level results spreadsheetsClick here
CommercialCalifornia Title 24 20195050%90.1-2019 Energy Index for CA. T24 would likely be higherPNNL State-level results spreadsheetsClick here
ResidentialCalifornia Title 24 20165348%2021 IECC Energy Index for CA. T24 would likely be higherPNNL State-level results spreadsheetsClick here
CommercialCalifornia Title 24 2022
81%


CommercialNYStretch 20184852%Percent energy savings over 90.1-2013PNNL/NBI Determination AnalysisClick here
CommercialMassachusetts Stretch Code 20174555%Ten percent improvement over base code energy indexBase code Energy Index per PNNL AnalysisClick here
CommercialMassachusetts Stretch Code 20204258%Ten percent improvement over base code energy indexBase code Energy Index per PNNL AnalysisClick here
CommercialASHRAE 189.1-20204654%5% better than 90.1-2019 - From targeted 5% improvement in Building Performance Factors (BPF)ASHRAE Standard 189.1 Text

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.