- The U.S. Department of Energy is considering new energy efficiency standards for manufactured housing, and plans to release a supplemental notice of proposed rulemaking (SNOPR) by Aug. 16 that will be based on the 2021 version of the International Energy Conservation Code (IECC). The agency published a related notice on Wednesday, detailing plans to consider the air quality impacts of sealing manufactured homes more tightly.
- Energy conservation portions of current manufactured housing regulations have not been adjusted since 1994, and according to the American Council for an Energy-Efficient Economy (ACEEE), these types of homes use 70% more energy per square foot than traditional "stick-built" homes.
- Roughly 7 million manufactured homes are in the United States, with the majority located in rural areas. "Energy bills can be very high and it's a very low income population living in them," said Lowell Ungar, who leads the federal policy program at ACEEE.
There are about 100,000 manufactured homes constructed in the U.S. every year and new builds can be highly efficient, with zero-loss, air-tight shells. The standards DOE is developing will apply to new homes, meaning significant energy savings as millions of older homes in use are ultimately replaced.
Manufactured homes are regulated by a federal standard because they are constructed in factories that may ship to multiple states. The Department of Housing and Urban Development sets the standards on the advice of its Manufactured Housing Consensus Committee, but those standards include energy provisions that have not been updated in more than 25 years.
In 2007, Congress directed DOE to establish energy conservation standards for manufactured housing, but so far none have been finalized. Efficiency advocates DOE is nine years behind requirements to set a new standard.
"For rural [electric] cooperatives, manufactured housing is quite significant," said Ungar. "It's an area that certainly some utility and efficiency programs have been interested in. There's a large opportunity because the current homes tend to be so inefficient."
A draft standard DOE considered in 2016 was estimated to potentially save manufactured home owners thousands of dollars over the lifetime of the home, but it was not published by President Donald Trump's administration.
DOE was sued by Sierra Club in 2017 over the failure to publish the rule, and their settlement requires the agency to finalize new standards in the first quarter of 2022.
The National Rural Electric Cooperative Association supported the proposed 2016 standard, but was unable to comment on current attempts to update conservation rules. The 2016 proposal would have reduced manufactured home energy demand more than a quarter, the group said.
Any new efficiency rules will need to tackle air quality issues, which have been flagged because new manufactured homes that can be air tight. On Wednesday, DOE published a notice of intent to prepare an environmental impact statement (EIS) on the impacts of sealing manufactured homes more tightly, to evaluate the potential impacts associated with updating conservation standards.
The agency said its new manufactured home standards would impact: the building thermal envelope; air sealing; installation of insulation; duct sealing; heating, ventilation and air conditioning; service hot water systems; mechanical ventilation fan efficacy; and heating and cooling equipment sizing.
DOE also said it is considering a "tiered approach" to address affordability and cost-effectiveness concerns with the efficiency rule.
The Manufactured Housing Association for Regulatory Reform opposed the 2016 proposed standards and warned the "outrageous requirements" could drive up the price of manufactured homes by $6,000 or more.
Under DOE's tiered approach, for manufactured homes below a certain retail price, "the stringency of certain building thermal envelope requirements would be based on incremental costs that provide a beneficial financial outcome with respect to life-cycle cost savings, while minimizing upfront cost impacts." That retail price has yet to be set, the agency said.
The price impacts of rules are important, said Ungar, because manufactured homes often function as low-income housing. And upgrades can be tricky because the homes often need so much work.
"You can do retrofits and improvements ... there are some really nice programs," Ungar said. "There also are really old mobile homes. Some are in really bad shape but people are still living in them. It doesn't make sense to fix them."
ACEEE's policy recommendations for manufactured home rules point out that electric heat pumps can help reduce costs and improve safety and air quality compared with propane or gas heating in manufactured homes. A "straightforward approach" to new rules "would be to require ENERGY STAR equipment for heating, cooling, and lighting," the group said. "More-aggressive measures could push further electrification as long as it is cost effective."
DOE says its Office of Energy Efficiency and Renewable Energy plans to finalize the SNOPR by the middle of August. Comments on the EIS notice for sealing manufactured homes will be due within 45 days of its publication in the Federal Register. DOE is now taking comments on the scope of the EIS until Aug. 6.
DOE plans to hold virtual information and scoping meetings to discuss the EIS on July 21 and 22.