Key Takeaways From Recent IECC Code Development Hearings

Code officials, architects, builders, engineers and energy conservation professionals gathered last month in Albuquerque for the International Energy Conservation Code (IECC)’s Committee Action Hearings. The proceedings were the first step in a lengthy stakeholder process to update the 2021 IECC, which is the most widely adopted energy code used by states and local governments in the United States. The 2021 IECC, which will be voted on by eligible ICC members in November, is the best near-term opportunity to reduce energy demand and curb carbon impacts from new buildings across the United States. At the end of 11 days of hearings, energy efficiency advocates had plenty of reasons to be optimistic that the stringency of the 2021 IECC will be vastly improved compared to the 2018 IECC.

Weighing in on Energy Codes

The much-anticipated Committee Action Hearings occur only every three years. During the hearings, advocates presented more than 550 proposals through more than 110 hours of testimony. NBI along with a broad group of partners presented 30 proposals to the residential and commercial technical advisory committees aimed at improving the efficiency of the IECC by 10-15%. While many hoped to see the residential provisions of the IECC go further than they did, important changes were made. On the commercial code, the code development committee passed several strong proposals representing significant increases in building energy performance.

Changes to the 2021 IECC Residential Code

The residential committee approved several proposals that, if adopted this Fall, will result in either increases in efficiency or improved understanding and clarity of the code leading to increased energy savings.

Building Envelope. The code will require more efficient glazing U-factors in Climate Zones 2 – 4. All ductwork in the house, regardless of location, will require air leakage (duct blaster) testing to ensure that the air from the ducted system arrives at the space where it was intended. The committee approved a duct leakage testing standard, RESNET Standard 380, which will specify a proven method for testing rather than “any method” as is currently the case. In addition, ventilation systems installed to increase indoor air quality must be tested to ensure the exhaust fan is moving the correct amount of airflow. These fans will also need to be more efficient, as the fan efficacy requirements were increased to meet Energy Star Version 4 levels.

Lighting. Lighting efficacy was increased to favor LED technology. As important as these proposals were to increased efficiency, significant energy savings were left on the table with the narrow disapproval of the Flexpoint proposal. Flexpoints offer a prescriptive method for increasing efficiency in the code by requiring the code user to comply with the prescriptive requirements of the code and then select additional efficiency measures totaling an additional 5% increase in energy savings.

Zero Energy Homes. NBI worked with our partners in the building and solar industry to develop an optional Zero Energy appendix that could be adopted by local jurisdictions to provide them a clear path to Zero Energy residential construction. Unfortunately, the proposal failed by one vote. This was a huge disappointment to NBI but we’re encouraged by the fact that so many states and cities have committed to meeting the goals of the Paris Climate Agreement and view Zero Energy construction as a key to reaching their climate goals. If adopted by a jurisdiction, the Zero Energy appendix would require a house to first meet a low Energy Rating Index (ERI) score before considering renewables, to ensure that the house is very efficient, and then add renewables to get an ERI score of “0”.

Changes to the 2021 IECC Commercial Code

While it was disappointing to many that significant energy savings were left on the table in the residential 2021 IECC, many were happy to see that the technical committee approved a high number of commercial code proposals.

Envelope. Starting with the building envelope, both the opaque envelope and fenestration requirements were upgraded to meet the more stringent of either ASHRAE or the IECC. A proposal to make building envelope air leakage (blower door) testing mandatory for most commercial and high-rise residential buildings was approved. And, envelope air barrier verification will be required for all buildings that are not tested.

Heating, Ventilation and Air Conditioning (HVAC). For HVAC systems, the equipment efficiency tables were updated to be consistent with ASHRAE 90.1-2019. Exhaust fan efficacy requirements were put into the code that cover small exhaust fans typically installed in multifamily.

Water Heating. The efficiency for high-input service water heating systems was increased to 92%, which is expected to result in substantial energy savings, especially in multifamily and hotel projects that have high hot water use.

Lighting. Lighting systems also became more efficient as the allowed lighting power density requirements were reduced by as much as 19% for some occupancies. Controls that automatically turn off receptacles are now required by the code, which is expected to create huge energy savings from plug loads .

Options Packages. The most significant structural change in the commercial code was converting the C406 Option Packages to a points based format. The conversion requires the designer to select efficiency measures totaling 10 points, with points assigned based on occupancy type and climate zone. This change recognizes that savings from efficiency features varies based on climate zone and occupancy type and assigns points accordingly to ensure that all buildings achieve at least a 2.5.% increase in efficiency.

Renewable Energy in the 2021 IECC Commercial Code

Both the residential and commercial code technical committees heard several proposals related to renewable energy. First and foremost, an industry standard definition of renewable energy was approved, which will be added to both the IECC and the ASHRAE model codes. The renewable energy additions to the commercial code maintain the industry’s focus on maximizing building energy efficiency first before adding renewables. Approved proposals include requiring renewable energy certificates to be retired with the building owner. Jurisdictions can adopt a renewable energy appendix that would require residential projects to install renewables.

What’s Next?

On Tuesday, June 25, 2019, join me for a free webinar about the outcomes from the recent IECC hearings in Albuquerque and the best opportunities for achieving substantial energy savings in this important model energy code cycle.

This 90-minute webinar (10:00 AM – 11:30 AM PDT) will feature experts who attended the hearings. Learn about this important process that culminates in a November vote and discover how you can help make a difference in the final outcome of the 2021 IECC.

Register here.


Written by: Eric Makela, Associate Director