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Stretch Codes

The U.S. Department of Energy (DOE) and Pacific Northwest National Laboratory (PNNL) are developing a series of technical briefs supporting national, state, and local initiatives to update and advance building energy codes. These technical briefs are presented in a module-based format, based on technologies, measures or practices (or optimized combinations) that can be incorporated as “plug-ins” to building energy codes. These plug-ins are made available for adoption directly by state and local governments pursuing advanced energy savings and greenhouse gas (GHG) emissions reductions, as well as for future consideration for the International Energy Conservation Code (IECC) and Standard 90.1. The collection supports the adoption of stretch codes, helping state and local governments pursue their energy and climate goals, as well as the Department’s broader mission to provide technical assistance supporting the implementation of state and local energy codes (42 USC 6833).

Currently available plug-ins are presented below. Each tech brief provides an overview of a given topic, plus supporting technical information and analysis estimating the associated impacts. In addition, sample code language is provided to illustrate how a given concept can be overlaid on top of the current model codes (e.g., IECC or Standard 90.1). Additional technical assistance is available from DOE and PNNL to support states and local governments who are interested in adding these concepts or other “stretch” provisions to their building codes. Assistance typically includes technical guidance, customized analysis of expected impacts (e.g., based on state-specific building stock, climate considerations, or utility prices), and further tailored code language to overlay state building codes or other standards. DOE works continuously with states and local governments to identify new concepts and practices that support their needs and plans to issue additional plug-in concepts in the future on a rolling basis.

Technical Briefs

Title Description Report Link Fact Sheet Link
Zero Code Plug-In This commercial zero code plug-in technical brief presents modified code language that can be amended to adopted commercial building model energy codes to achieve net zero operational energy emissions (NZOEE) or net zero energy (NZE) in newly constructed buildings, either immediately or over several code cycles. Commercial Plug-In  
EV Charging

Numerous studies show that sales of plug-in electric vehicles (PEVs) have grown consistently over the past 2 years in the U.S. Edison Electric Institute (EEI) estimates one million PEVs on the road in 2018 and forecasts a total of 18.7 million PEVs on the road by 2030. Based on this forecast, EEI projects the need for an additional 9.6 million PEV charging stations by 2030.

States and local governments have expressed interest to DOE in having energy code overlay requirements to support policy goals. This technical brief provides code language for PEV charging infrastructure for adoption by model codes, and states and local governments.

EV Tech Brief EV Fact Sheet
Simplified HVAC System Performance

The technical brief provides an additional heating, ventilation, and air conditioning (HVAC) System Performance (HSP) path that goes beyond the prescriptive energy code. It provides a comprehensive performance-based approach for HVAC system evaluation and analysis. The approach develops a Total System Performance Ratio (TSPR) to compare proposed, target, and reference HVAC systems.

The technical support documentation (TSD) provides background on development of mechanical system performance factors for use in the HSP for ASHRAE Standard 90.1-2022. It provides documentation of HVAC system input parameters and simplified HVAC measure modeling approaches.

HSP Tech Brief




HSP Fact Sheet
Energy Credits This technical brief provides additional energy efficiency measures that go beyond the current prescriptive commercial energy codes. It demonstrates relative savings for multiple measures and shows a base savings package by building type and climate zone that is cost effective for building owners and tenants. Energy Credits Tech Brief
Energy Credits Application Guide: ASHRAE Standard 90.1-2022
Energy Credits Fact Sheet
Electric Readiness This technical brief provides requirements for electric readiness that could be incorporated into model residential energy codes. It provides background on the basis and benefits of the provisions, and model code language that can be plugged into the IECC or adapted into other energy codes.

Electric Readiness Tech Brief

Electric Readiness Fact Sheet
GEB (Demand Response) This technical brief provides requirements for demand-responsive thermostats and water heaters that could be incorporated into model residential energy codes. It provides background on the benefits of these devices, impacts on the cost of construction, and model code language that can be plugged into the IECC or adapted into other energy codes. GEB Tech Brief GEB Fact Sheet

Code Change Proposals Currently Being Considered

Below are draft code change proposals DOE is considering for stretch code and model code development.

Title Proposal Link
Clarify Slab Insulation Requirements Proposal
Commercial PV Required Proposal
Decorative Lighting Power Reduction Proposal
Demand Control Ventilation Update Proposal
EV Charging Proposal
Expanded C406 Energy and Demand Response Credits Proposal
Exterior Lighting Proposal
HVAC Total System Performance Ratio Proposal
Interior Lighting LPD Update Proposal
Lighting System Performance Proposal
Residential Demand Response Proposal
Residential Electrification Proposal
Residential PV Required Proposal
Residential Renewable Tradeoffs for Performance Path Proposal

Other Resources

Building Energy Codes and Grid-Interactive Efficient Buildings

Filling the Efficiency Gap to Achieve Zero-Energy Buildings with Energy Codes

Realizing Demand Flexibility with Commercial Building Energy Codes

DOE Building Energy Codes Program

The U.S. Department of Energy supports the advancement of building energy codes, including stretch codes that empower states and local governments in achieving their energy and climate goals. Modern building codes and standards offer cost-effective solutions, contributing to lower utility bills for homes and businesses, and helping to mitigate the impacts of climate change. Learn more at