A research team from Parsons School of Design’s Healthy Material Lab has published findings warning that a typical American manufactured home is built almost entirely from petrochemical-derived plastics, materials the group says carry health and environmental costs that go largely unexamined by buyers and regulators alike.
The report, titled Manufactured Homes: An Analysis of Health and Environmental Impacts of Common Building Materials, was compiled by examining a single manufactured home sold in Minnesota by Northstar Systembuilt. To gather details on the materials used, researchers contacted the manufacturer directly, presenting themselves as prospective buyers rather than identifying themselves as academics.
What the manufactured homes study found
The team’s conclusion is blunt: plastics such as polyethylene, polyvinyl chloride and polypropylene turned up across nearly every part of the dwelling, from flooring and cabinetry to paint and insulation, with concentrations especially high in kitchens and bathrooms. As the study itself put it, “the extensive use of petrochemical-based materials in contemporary manufactured housing poses significant health and environmental risks,” adding that “plastics and their associated toxic additives are found in nearly every major surface within a manufactured home.”
Manufactured housing has a long history in the United States and its production has fallen sharply since its heyday. In the 1970s the industry was shipping as many as 500,000 units a month; Census Bureau figures cited in the research put the current pace at closer to 100,000 monthly deliveries.
Why researchers focused on affordability
Jonsara Ruth, executive design director at Healthy Material Lab, said the problem of plastic-laden construction extends well beyond manufactured housing but becomes especially visible in this segment of the market. “It’s true, petroleum-based plastic materials are now widespread in new American homes, not just manufactured ones,” she said. “But manufactured housing offers a unique lens: it’s where affordability and conventional construction intersect most starkly, often resulting in material choices that externalize health and environmental costs.”
Ruth pointed to the work of Dr Shanna Swan on links between plastic exposure and human health, as well as the Green Science Policy Institute’s framework identifying harmful chemical classes, as context for the study’s concerns. She also placed the findings in a longer historical arc, noting that “longstanding reports, dating back to the 1990s, discuss the increased use of petrochemical-based materials in housing and associated health concerns,” and pointing to a well-known precedent: “the FEMA trailer crisis after Hurricane Katrina highlighted the dangers of high formaldehyde exposure in temporary homes.”
Ruth acknowledged the limits of building an entire study around one home. “We selected one of the most affordable models from one of the largest manufactured home manufacturers in the US,” she said. “While this isn’t a statistically representative sample, it’s a typical example of conventional, low-cost manufactured homes.” She added that she believed the material findings were consistent with what tends to appear in affordable, conventional residential construction generally across the country. Northstar Systembuilt has not responded to press inquiries about the study.
Pushing for lower-toxicity alternatives
The Healthy Material Lab team frames its work as constructive rather than oppositional. Researchers pointed to swaps that could reduce plastic dependence, such as linoleum flooring in place of vinyl or wood finishes instead of plastic laminates. Ruth cited a 2000 partnership between Enterprise Community Partners and Clayton Homes as an example of manufacturers attempting to improve material choices.
“We’re not arguing against manufactured homes,” Ruth said. “In fact, we’re arguing for healthier, low-carbon prefabricated housing at an affordable price point.”
The study lands amid broader scrutiny of plastics in the built environment, including recent attention to microplastic exposure indoors, and follows examples elsewhere in the design world, such as a 2024 project by Denmark’s Natural Material Studio that built a home interior without any fossil-fuel-derived materials. No timeline for regulatory response or industry changes has been announced.
What a house is made of is a health question before it is an aesthetic one. Our guide to sustainable materials covers the alternatives, and biocompatible materials looks at what replaces the petrochemical default.
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