Energy Code Adoption Toolkit


residential modern home in basalt colorado

The Colorado Energy Office (CEO) created this Energy Code Adoption Toolkit to assist Colorado jurisdictions through the process of energy code adoption. The toolkit provides information on the benefits of adopting a more current energy code and gives tips on how to navigate the typical adoption process. It also includes several resources that:

  • Detail the costs of updating an energy code
  • Describe changes made in the latest version of the International Energy Conservation Code (IECC)
  • Provide example language for the adoption of stretch codes that go beyond the IECC
  • Help jurisdictions verify code compliance 

The resources in this Energy Code Adoption Toolkit are designed to put all of the necessary code adoption information in one place, while walking your jurisdiction through the process.

When adopting building codes, the Chief Building Official (CBO) often discusses the update with various stakeholders including the City Council, the Board of County Commissioners, and the local building community, among others. This section provides talking points for the CBO when having these discussions, in order to advocate for why adopting a more current energy code will benefit their community.

Lower Insurance Rates for Jurisdictions

The Building Code Effectiveness Grading Schedule (BCEGS) program could lead to a lower insurance rate through assigning a jurisdiction a classification from 1 (exemplary commitment to fire and building code enforcement) to 10 (not committed). This is similar to the Public Protection Classification program that is in place for fire protection, but the BCEGS program is based on building code enforcement. The assigned classification takes into account what current fire and building codes are in place, the retention of the code’s structural provisions, code official qualifications and public awareness programs. In other words, if your jurisdiction elects to adopt the latest energy code, your jurisdiction may receive a discounted insurance rate.

For more information, visit the ISO Mitigation website.

Energy Cost Savings

Any measure that is enacted in each new version of the IECC must show energy cost savings. This means that most buildings are able to see a return on investment in only a few years through the savings that are acquired through their energy bills. See the Cost Impacts of Updating Energy Codes section of this toolkit for a summary of cost savings by IECC version.

Contribution to Local Climate Action Plans

Many jurisdictions have adopted Climate Action Plans (CAP) to meet community goals related to greenhouse gas emissions reductions and resiliency.  These plans often outline an emission inventory, detailing where emissions are generated in the community. Building energy consumption is consistently a large contributor to local emissions, and therefore building energy codes are a key strategy for communities to meet the goals in their CAP.  CAPs may be the responsibility of another department such as Planning or Sustainability.  Coordinating with this department and discussing how an energy code update could contribute to community CAP goals could create additional support for the code update.

Available Training and Software

Did you know that the Colorado Energy Office offers free training on the latest energy codes? By adopting a more recent energy code, there are many more resources to train building code officials that are often at no expense to your jurisdiction. It's also important to note that the U.S. Department of Energy only supports the most recent energy code editions in the REScheckTM and COMcheckTM software that is used for determining compliance.

CEO-sponsored recorded webinar IECC trainings are available at these two locations:

2019-2020 Webinars (accessed through Google Drive)

2018-2019 Webinars (accessed through GoToStage)

Consistency for Designers and Builders

Colorado is a home rule state, which grants jurisdictions local control over which building and energy code is adopted (though Colorado state statute requires jurisdictions to adopt one of the three most recent versions of the IECC upon adopting or updating any other building code). Since designers and builders work in multiple jurisdictions, a consistent code reduces their time and cost of designing and building to different code requirements. For production builders, it also means they don’t have to customize standard designs to comply with each jurisdiction's code. Adopting the same code requirements as neighboring jurisdictions also helps designers and builders become more familiar with consistent code requirements, likely reducing plan check correction comments or inspection items.

Flexibility for Homebuilders

In the 2015 IECC, a new compliance path was added for residential applications called the Energy Rating Index path (ERI). This compliance path was improved upon in the 2018 IECC. Builders who choose to use the ERI obtain a score ranging from 0 to 100, where zero represents a net zero energy home and a score of 100 represents a home built to the 2006 IECC. Each point in the scale represents a one percent change in the relative energy efficiency of the home; lower ERI scores equate to improved efficiency. The ERI compliance path can make it easier for both homebuilders to comply with code and for plan examiners to verify compliance.


As the IECC continues to develop through each code cycle, homes and buildings are becoming more resilient as they incorporate newer materials, techniques and technologies that come to market. Buildings are being better built with an improved ability to endure severe weather and changes in the atmosphere, including storms, moisture, temperature swings, and more. With these advancements also come increased durability, safety, and comfort for occupants who may need to shelter in place during these weather events. In its 2019 report, the National Institute of Building Sciences found that adopting the 2018 codes has a benefit-cost ratio of $11 for every $1 spent. Building codes are an extremely cost-effective strategy for making your community's built environment safer and more resilient to natural and man-made hazards.

Staying Up to Date with Building Code Adoption

In 2019 the Colorado Legislature passed HB19-1260, which requires local jurisdictions to adopt one of the three most recent versions of the IECC, upon updating or adopting any other building code. Jurisdictions can adopt codes on their own schedule, but the goal is to keep them fairly up to date without requiring new legislation.

CEO recommends adopting the corresponding edition of the IECC as part of a jurisdiction’s entire package of building codes. The I-Codes are written to be adopted together and that limits conflicts between the IECC and other building codes like the International Building Code, the Residential Code and the International Mechanical Code.

CEO has put together visual guides of typical energy code adoption and compliance processes.  Processes may vary by jurisdiction but these guides give a generic view of the steps necessary to adopt and comply with an energy code, and who is typically involved to do so.

To see a map of the typical code adoption process and compliance process, click here.

Scaling Multiple Code Cycles at Once

It can be daunting to move from an older edition of the IECC to a newer one, especially when skipping several code versions. CEO offers free technical assistance for jurisdictions adopting the latest energy code to help through this process. The assistance can be customized to a jurisdiction’s needs and used to help work through the adoption process. To request technical assistance, please fill out this short form: Technical Assistance Request.

There are multiple sources of upfront costs to consider when updating to a newer code. For a jurisdiction, the costs of code books, training, outreach, publishing notices and the added construction costs must be accounted for at a minimum. As new codes are adopted, the update also may require more staff to enforce provisions correctly unless the new code requirements can fit into what the jurisdiction’s staff is already implementing. It's also worth noting however, the building codes are an extremely cost-effective approach to making your community's built environment more resilient to natural and man-made hazards.

Accounting for Costs to Your Jurisdiction

  1. View these Residential and Commercial Code Comparison documents to see how the code has changed from the 2009 IECC to the 2018. These documents can be used to estimate the impact each measure has on your jurisdiction’s code adoption plan and decide if your jurisdiction needs more staff to implement these code changes properly.
  2. Find out how much your jurisdiction spends on books. Free versions of the 2018 I-codes can be accessed here. An estimate of how much it is to purchase a set of hard copies for all of the I-codes can cost upwards of $1,000.
  3. Look for free training opportunities provided by the Colorado Energy Office, Xcel Energy or other local groups to offset the cost of training your staff.
  4. Account for marketing costs to update website information and to send publishing notices.

Construction Costs

The initial design and construction decisions determine what the operational and maintenance costs will be for the building and therefore, it's important to look at when a building can start to see a return on investment. The National Association of Home Builders (NAHB) published an “Estimated Cost of the 2018 IRC Code Changes” research paper that found that adopting the 2018 codes actually decreases residential construction costs for Colorado’s climate zones when compared to building to the 2015 codes.

Furthermore, in May 2019, the U.S. Department of Energy published a study, "Preliminary Energy Savings Analysis: 2018 IECC Residential Requirements" which found that in Colorado's climate zones, homes built to the 2018 IECC will save approximately 2 percent in annual energy costs.

Residential Costs and Savings for moving to a new version of the IECC Commercial costs and savings IECC tables

There are minimal changes between the 2015 IECC and the 2018 IECC. This document provides an easy-to-follow guide on the significant changes for both the residential and commercial codes. For residential, the largest changes are within lighting, thermal envelope and the Energy Rating Index. Major changes in the commercial code include lighting, additional efficiency package options and thermal envelope.

We also have a summary of the significant changes between the 2009 and the 2015 Commercial IECC. 

Stretch codes refer to adding code requirements that go above and beyond the base code, which is in most instances a version of the IECC. Below we’ve provided a few examples of codes that incorporate advanced design and technology practices. To see some examples of the advanced code language used locally in Colorado, click here.

The New Buildings Institute published a white paper, "Energy Code Roadmap for Getting to Zero Outcomes," in February 2020 that describes a process by which jurisdictions can incrementally strengthen building performance standards through codes over time in order to decarbonize the building sector.

Electric Vehicle (EV) Ready

An EV-ready building is constructed with the electrical capacity and pre-wiring to enable the future installation of EV charging stations. Requiring new commercial buildings to incorporate EV-ready infrastructure can save thousands of dollars—or up to 80 percent of the cost—when compared to retrofitting a commercial EV charging station. Making a new single-family home EV-ready during construction can be several hundred dollars cheaper than retrofitting it in the future. CEO recommends that jurisdictions add an amendment or ordinance to require EV-ready infrastructure in residential and commercial new construction. By doing so, your jurisdiction will be set up to abide by the EV requirements in the 2021 IECC.

NEW! The Southwest Energy Efficiency Project (SWEEP) developed an EV Infrastructure Building Codes: Adoption Toolkit that answers common questions about EV building codes and electrical capacity requirements, infrastructure costs, and includes sample language and instructions for how jurisdictions can easily add EV-ready amendments into their code. 

Solar Ready

Solar ready buildings are designed and constructed to facilitate and optimize the installation of a rooftop solar photovoltaic (PV) system for future use. Solar ready code language can minimize expensive infrastructure upgrades in the future, ensuring the feasibility and optimization of solar PV installation and placement. In Appendix CA of the 2018 IECC, there is code language already available and ready to adopt as part of the base code for jurisdictions.

ZERH (Zero Energy Ready Homes)

A U.S. Department of Energy (DOE) Zero Energy Ready Home (ZERH) is a home that meets all of the criteria found in the DOE ZERH National Program Requirements. DOE ZERH are verified by a qualified third party and are at least 40% to 50% more energy efficient than a typical new home. This generally corresponds to a Home Energy Rating System (HERS) Index Score in the low 50s, depending on the size of the home and region in which it is built. All DOE ZERH are so efficient that the addition of an onsite renewable energy system can offset most or all of the home’s annual energy consumption.

All-Electric New Construction

As the electrical grid decarbonizes due to an increasing supply of renewable energy generation, municipalities and counties looking for ways to further reduce greenhouse gas emissions from burning fossil fuels have adopted ordinances or building codes that require newly constructed buildings to be all-electric. There are currently 30 jurisdictions in California that have passed all-electric new construction mandates, in addition to dozens of cities across the U.S. that are considering such a move. Building beneficial electrification involves installing energy-efficient electric equipment—such as heat pumps for space heating and cooling, heat pump water heaters, and induction cooktops—in place of combustion-fueled (typically propane or natural gas) equipment. Benefits of electrification include better indoor air quality, safety from gas leaks, savings from no first costs of natural gas infrastructure installation, as well as fewer emissions from a cleaner electrical grid.

NEW! SWEEP's report, Building Electrification: How Cities and Counties are Implementing Electrification Policies (July 2020) provides case studies from a dozen local governments on how they adopted code language to advance beneficial electrification.

International Green Construction Code (IgCC)

The IgCC provides a comprehensive set of requirements intended to reduce the negative impact of buildings on the natural environment. It is a document which can be used readily by manufacturers, design professionals and contractors. What sets it apart in the world of green building is that it was created with the intent to be administered by code officials and adopted by governmental units at any level as a tool to drive green building. With that said, unless your jurisdiction has the staff to enforce the entire IgCC, then it may be worth looking through the IgCC and only adopting sections that align with your community’s goals to start. The IgCC covers a variety of topics, including indoor air quality, energy, water, waste, materials, operation and more.

High Performance Energy Codes around the Country

In addition to stretch codes implemented in Colorado, below are some examples of stretch codes or custom codes being used elsewhere that could be used for inspiration.

Building Benchmarking 

Benchmarking refers to measuring a building’s energy consumption. Enacting building benchmarking ordinances are becoming a more common approach for jurisdictions to increase transparency and accountability for how buildings use energy, and they can help cities achieve their climate and sustainability goals. Cities such as Boulder, Denver and Fort Collins in Colorado as well as cities across the country including Boston, Chicago, Des Moines, Kansas City, Los Angeles, New York, Orlando, Seattle, and Washington, D.C., have passed ordinances requiring building owners to report their energy use on an annual basis. In addition to tracking energy use, some jurisdictions also include requirements to track and report water consumption. The data is often shared on a publicly-accessible online map or database.

The majority of programs stipulate that building owners enter their data using the EPA’s ENERGY STAR Portfolio Manager, a free energy, water, and waste management software tool. Buildings can receive an ENERGY STAR score, on a 1 to 100 scale, which compares a building’s energy performance against similar buildings across the country. A score of 50 represents the median, while a score of 75 means that the building performs better than 75 percent of similar buildings nationwide.  

Many ordinances require reporting for buildings that meet a minimum square footage, for example buildings 25,000 square feet or larger. Benchmarking programs enable building owners to identify buildings that use more energy and water, evaluate cost-effective savings opportunities, and prioritize investments in efficiency upgrades. Some jurisdictions have also enacted performance standards which require buildings to meet a minimum ENERGY STAR score or to conduct efficiency assessments or upgrades.

Here are links to benchmarking programs across Colorado:

We’ve compiled the following resources to support the energy code compliance process. 

NEW! Troubleshooting Code Interpretation Guide - This guide provides explanations for some commonly-asked questions on how the 2018 IECC interacts with the other I-codes and how to interpret mechanical, electrical, envelope and additional efficiency package code measures. It also provides clarification on compliance and enforcement roadblocks that multiple jurisdictions across the state of Colorado have encountered.

Plans Examiner Checklists

Building Inspector Checklist: 2015 IECC available for purchase

Commissioning Checklist: 2018 IECC Commissioning Checklist

RESCheckTM and COMCheckTM Plan Review Guide

Guides for verification of Manuals J, D, S and N are provided on ACCA’s website or follow these cheat sheets: