Proposals to Improve Manufactured Housing

The National Center for Healthy Housing submitted four proposals in November 2007 to make manufactured housing healthier. The proposals addressed the following topics:

  • Ventilation
  • Formaldehyde
  • Carbon Monoxide Alarms
  • Toilet Rooms

In addition, the Louisiana Department of Health submitted a proposal to prevent plumbing problems.


The U.S. Department of Housing and Urban Development sets construction and safety standards for manufactured housing. Manufactured housing is also known as mobile homes. These federal standards preempt state or local requirements that are not identical. State and local requirements cannot be more stringent than the federal level. The federal standards are essentially the building code and housing code for manufactured housing.

HUD’s Manufactured Home Construction and Safety Standards apply to a structure transportable in one or more sections:

  • Which in the traveling mode, is eight body feet or more in width or 40 body feet or more in length; or,
  • When erected on site, is 320 or more square feet, and which:
    • Is built on a permanent chassis; and
    • Is designed to be used as a dwelling with or without a permanent foundation when connected to the required utilities; and
    • Includes the plumbing, heating, air conditioning, and electrical systems contained therein.

HUD arranges for the Manufactured Housing Consensus Committee (MHCC) to review proposals to revise the standards and make recommendations to HUD. HUD revises the standards based on the recommendations. The National Fire Protection Association (NFPA) manages the MHCC.

HUD does not have to accept the recommendations of the MHCC. For example, in its November 30, 2005 revisions to the rules, HUD rejected MHCC’s recommendation to eliminate the health notices regarding formaldehyde emissions. HUD had too many unanswered questions about formaldehyde in manufactured housing to eliminate the notice to consumers.

The MHCC launched a new round of revisions by accepted proposals from the public in a May 4, 2007 Federal Register announcement. Proposals were due on before December 1, 2007. NCHH submitted four proposals.

NCHH submitted four proposals to the Manufactured Housing Consensus Committee to revise 24 CFR 3280. The purpose of these proposals is to improve the health of residents in manufactured housing.


Statement of Problem and Substantiation for Proposal: Poor indoor air quality is associated with adverse health effects. A consensus industry standard that provides adequate indoor air quality has been established by the American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE). The most effective method of controlling indoor air exposure to pollutants is to prevent them from being released into the air in the first place and by providing sufficient fresh air. The ASHRAE standard requires source-control measures that exhaust pollutants from specific rooms, such as bathrooms, before the pollutants enter the rest of the house. This change will increase the cost of construction slightly. It will result in significantly healthier air for residents of manufactured housing.

Proposal: Add new paragraph (d) to section 103 as follows:

“(d) The manufactured housing must comply with ANSI/ASHRAE Standard 62.2, Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings.”


Statement of Problem and Substantiation for Proposal: Formaldehyde is a significant respiratory irritant and health threat to residents, especially residents with asthma or those who have been sensitized. In April 2007, the California Air Resources Board (CARB) adopted standards that achieve the lowest exposures from composite wood products. The CARB standards have a four-year phase-in period. The cost will be approximately 10% higher and will be offset by fewer health-related costs associated with exposure to formaldehyde.

Proposal: Add new paragraph (e) to section 308 as follows:

“(e) Manufactured housing constructed after January 1, 2012 that contains plywood and/or particleboard must use only plywood and/or particleboard that complies with Title 17 Section 93120 to 93120.12 of the California Code of Regulations for airborne toxic control measure to reduce formaldehyde emissions from composite wood products.”

Carbon Monoxide Alarms

Statement of Problem and Substantiation for Proposal: Annually, hundreds of people die and thousands are injured due to carbon monoxide (CO) poisoning. Properly installed, UL-listed, CO alarms can reduce that number dramatically. The federal government, including CPSC, CDC, U.S. Fire Service, and HUD, recommends installing a UL-listed carbon monoxide alarm. For the HUD recommendation, see A CO alarm costs around $25 and has nominal installation costs when coordinated with a smoke alarm.

Proposal: Add new section 24 CFR 3280.210 stating the following:

“If manufactured housing is equipped with a fossil fuel-fired furnace, fossil-fuel powered hot water heater, fossil-fuel-powered space heater, fossil-fuel-powered stove or oven or other appliance combusting device in which carbon monoxide is produced, one carbon monoxide alarm must be installed next to each smoke alarm. The carbon monoxide alarm must be listed by the Underwriters Laboratories and have a peak level recorder. Home manufacturers must comply with the connection to a power source, notification, testing, and maintenance and installation requirements of Section 3280.208(d), (e), and (f) as if the carbon monoxide alarm were a smoke alarm.”

Toilet Room

Statement of Problem and Substantiation for Proposal: Non-absorbent materials in the wet surfaces of a bathroom, laundry room, and other wet rooms are essential for basic sanitation and hygiene. This requirement is common in housing codes across the United States. Materials used in wet rooms such as a toilet room must not support mold growth. In 2004, the Institute of Medicine concluded that mold in damp environments is associated with asthma, hypersensitivity pneumonitis, upper respiratory tract symptoms, coughing and wheezing. There is no additional cost from this proposed change, because alternative materials are readily available at the same or lower cost.

Proposal: Revise Section 111 as follows:

“Each toilet compartment shall be a minimum of 30 inches in width, except, when the toilet is located adjacent to the short dimension of the tub, the distance from the tub to the center line of the toilet shall not be less than 12 inches. At least 21 inches of clear space shall be provided in front of each toilet. The floor, shower, and tub areas must be constructed of non-absorbent surfaces that will not trap water and support mold growth. Vinyl wallpaper and paper-faced gypsum board and unsealed grout traps water and is not to be used in toilet rooms and bathrooms and laundry rooms. Wall-to-wall carpets or carpet pads shall not be installed in toilet rooms, bathrooms, or under concealed spaces subject to excessive moisture, such as plumbing fixture spaces, floor areas under installed laundry equipment.”