Department of Energy finalizes rule for Energy Conservation Standards for Manufactured Housing

On May 31, 2022, the U.S. Department of Energy (DOE) published a record of decision and final rule to the Federal Register, establishing updated energy conservation standards for manufactured housing. Pursuant to the Energy Independence and Security Act of 2007 (EISA), the energy requirements for manufactured housing will be based on the 2021 International Energy Conservation Code (IECC). The DOE codifies the energy conservation standards of the final rule in a newly established part of the Code of Regulations (CFR) under 10 CFR part 460, subparts A, B and C. The intended goal is to enhance energy conservation, reduce climate emissions and provide enhanced indoor air quality while balancing affordability and cost savings of manufactured homes.

Under Section 413 of the EISA, the DOE was required by regulation to establish energy conservation standards for manufactured housing. As directed, the standards were to be based on the most recent version of the IECC, including supplements, except in cases where DOE found that the code was not cost-effective, or a more stringent standard would be more cost-effective. Cost-effectiveness was measured by the impact that the implemented code would have on the purchase price of manufactured housing and total life-cycle construction and operating costs.

EISA required the DOE to complete this rulemaking nearly ten years ago. To date, energy efficiency requirements for manufactured housing remain tied to U.S. Department of Housing and Urban Development requirements (the “HUD Code”) which have not been updated since 1994.

As part of the rulemaking process, DOE considered three alternative approaches for establishing energy conservation standards for manufactured housing – in addition to the option of taking no action. Alternative A proposed tiered efficiency standards based on manufacturer retail listing price, while Alternative B proposed tiered standards based on size. Alternative C proposed an untiered standard which would have established the same energy conservation requirements for all manufactured homes and Alternative D represented taking no action. The DOE developed an Environmental Impact Statement (EIS), pursuant with the National Environmental Policy Act (NEPA), to further inform their rulemaking.

DOE formally decided on the establishment of tiered energy conservation standards for manufactured housing based on the size of the manufactured home. Subpart A of the regulation provides the scope and intent of the rule. Subpart B establishes requirements for building thermal envelope, air sealing, and installation of insulation based on identified provisions of the 2021 IECC. Separately, Subpart C establishes new requirements for duct sealing, heating, ventilation and air conditioning (HVAC), service hot water systems, mechanical ventilation fans, and heating and cooling equipment sizing based on 2021 IECC provisions.

The stringency of requirements under Subpart B of the new energy conservation standard will depend upon the size of the home, which introduces the two-tiered standard. Tier 1 applies to single-section manufactured homes, requiring building thermal envelope provisions that limit the increase in incremental purchase price less than $750. Tier 2 applies the site-built building thermal envelope provisions of the 2021 IECC for multi-section manufactured homes. The requirements also lower insulation for Tier 2 homes in certain climate zones. The DOE analysis concludes that the implementation of the new energy conservation standards for manufactured housing will save consumers $5.06 billion in costs and reduce carbon dioxide emissions by 80.4 million metric tons over 30 years.

The International Code Council participated in the various public participation opportunities presented throughout the rulemaking process to further inform the DOE’s decision. The rule will become effective on Aug. 1, 2022, with compliance of the adopted standards required beginning on May 31, 2023.