The standard, or an equivalent thereof, has been deployed in 14 states, according to HUD Exchange. In addition to the IECC, the rule called for using ASHRAE 90.1-2019 as the minimum energy-efficiency standard for certain single-family and multifamily housing programs. 

“By rescinding this mandate, we are removing a significant regulatory barrier that added tens of thousands of dollars to the cost of a new home,” said HUD Secretary Scott Turner. “The Trump Administration’s focus is to facilitate new housing supply and ensure that every American family has a path to homeownership without being sidelined by bureaucratic red tape.” 

The 2021 IECC is more stringent on energy efficiency, often requiring higher-efficiency HVAC systems and tighter duct and airflow standards. Systems such as heat pumps and variable-speed equipment are often used to comply with these standards. 

With the rescinding of the rule, homebuilders and HVAC companies alike will switch to less strict codes, depending on which state they’re in, resulting in low-cost, low-efficiency systems. As such, the ongoing push toward electrification may slow down. 

For HVAC, key differences between the 2021 and 2018 IECCs include requiring more efficient motors for ventilation equipment and mechanical ventilation systems to pass an air flow test. Rigorous blower door testing was also added to the newer code. HVAC systems with direct digital controls serving individuals must have automatic stop and start controls.  

Section R408 of the 2021 code called for additional efficiency options to be added to a house. This could consist of 100% of ducts and air handlers or 100% of ductless thermal distribution or hydronic thermal distribution systems being located inside the building’s thermal envelope. Other options included installing a 95% furnace/16 SEER air conditioner or an 82 EF gas water heater or 2 EF electric water heater. 

Housing Affordability 

Rescinding the 2024 rule could result in more affordable homes. According to the joint statement, the 2024 rule added $20,000-$31,000 to home construction costs. It also reportedly resulted in longer permitting and inspection timelines. 

For contractors, the administration’s actions could result in a quality versus quantity situation — there will likely be more homes requiring installs and service, but the systems will be simpler. Again, it varies depending on each state’s code variation, so larger contractors working in multiple states will want to check which codes apply. 

Construction prices have been rising due to higher oil prices caused by the conflict in Iran. In March, overall construction input prices were 4.8% higher than the same period a year ago. That is the largest annual increase since January 2023, according to data from the Bureau of Labor Statistics’ Producer Price Index. 

Bill Owens, chairman of the National Association of Home Builders, commended the decision to rescind the rule, characterizing it as overly burdensome energy mandates. 

“Compliance with the rule would have placed significant new cost pressures on home builders and multifamily developers, making it harder to deliver the affordable, attainable communities that are urgently needed,” Owens said in a written statement. 

Since entering office, the Trump administration has delayed the compliance date for the 2024 Final Determination. Most recently, HUD published an extension on Feb. 3 that delayed the deadline for HUD programs until Dec. 31, 2026.