Cut the steel, cut the cost: Why Congress is right to scrap the chassis mandate

If buying a home in the US feels more expensive, that is not merely your imagination. A Harvard University study found that national single-family home prices have risen to five times the median American’s income. Between 2019 and 2024, single-family home prices rose at more than twice the rate of the median income. Starter homes are in short supply and the median age of a first-time homebuyer is 40 years old, which is notably higher than the median age of the late 20s during the 1980s. Homeownership has become more elusive for the everyday American, so much so that it has caught the attention of Congress.

Last week, the House overwhelmingly passed a housing reform bill called the Housing for the 21^st Century Act (H.R. 6644). The bill includes several provisions intended to modernize housing regulations and reduce barriers to construction. Among these changes is a provision removing the federal requirement that all manufactured homes be built on a permanent steel chassis.

Framing the issue: manufactured homes and the steel chassis

Manufactured homes are factory-built homes that are transported to a site and installed, often on permanent foundations. These homes differ from modular or site-built homes in that most of the construction occurs before the home leaves the factory. Manufactured homes are available in a variety of sizes and configurations, offering flexibility in design and layout.

Most manufactured homes include a steel chassis, which is a structural frame attached during construction to allow safe transport from the factory to the site. While the chassis was originally essential for mobility, over 90 percent of manufactured homes constructed nowadays remain in place permanently. Understanding this key feature is important before reviewing the regulatory history and legal requirements that mandate it.

The chassis mandate story

When Congress enacted the National Mobile Home Construction and Safety Standards Act of 1974, it authorized the Department of Housing and Urban Development (HUD) to establish construction and safety standards for manufactured homes. This Act authorized HUD to establish the Manufactured Home Construction and Safety Standards. Part of these standards includes a mandate (24 C.F.R. § 3280.2) that manufactured homes be “built on a permanent chassis.”

When the HUD Code was first implemented, the chassis served a dual purpose: it provided structural support during transport, and it ensured the home met federal safety standards while in transit. This mandate had major ramifications because manufactured housing was a major part of the US housing market. The University of Texas points out that prior to the 1974 chassis requirement, nearly one in three new homes was manufactured. This declined to one in ten homes by 1980.

Meanwhile, engineering advances and production practices made the transport frame less essential over time. As early as the mid-1980s, the industry supported removing the chassis mandate. The Pew Charitable Trusts acknowledges only 5 to 7 percent of manufactured homes require a chassis after initial installation, thereby illustrating a disconnect between the regulatory requirement’s original mobility rationale.

Breaking the steel ceiling by removing the mandate

A regulation that still insists on a permanent chassis is a bureaucratic relic. This is even more the case considering its costs. According to the Niskanen Center, removing the chassis requirement would reduce the construction costs of each manufactured home by up to $5,000-$10,000. With thousands of homes built annually, this regulation adds hundreds of millions of dollars in needless housing costs.

To put this chassis cost into context, the national average sales price of a new manufactured home was $120,900 in early 2025. Removing the chassis from construction costs could lower the price of a manufactured home by 4 to 8 percent. For a first-time buyer or a working family, those savings could be the difference that encourages them to purchase a home.

This back-of-the-envelope calculation does not even consider the increased manufacturing complexity, inspection procedures, or transportation coordination that chassis require, all of which drive up labor and administrative expenses. Removing a regulation for a rarely used transport frame would trim these hidden regulatory expenses while reducing construction timelines.

Beyond regulatory costs, the chassis requirement comes with real design consequences. As the Federation of American Scientists details, requiring a chassis means that homes must sit higher off the ground, which precludes certain structural configurations. The chassis requirement prevents developers from building basements, slab-on-grade foundations, and multi-level units. Allowing manufactured homes to be constructed without this constraint would broaden where and how manufactured housing can compete with site-built construction, which could increase housing supply further.

Manufactured homes: a more affordable and timelier alternative

Manufactured homes cost less than one-third as much as their site-built counterparts. Even with the chassis requirement, the average sales price of a manufactured home was $124,500 in March 2025, compared to the 2025 Q1 average sales price of $423,000 for site-built homes. Repealing the chassis mandate would amplify that advantage by lowering prices even further and encouraging greater production at a time when housing supply is urgently needed.

Not only is manufactured housing cheaper, it is also faster to construct. Because these homes are largely built in factories, construction is not subject to the weather, subcontractor scheduling, or many on-site delays that slow traditional builds. HUD recognizes that manufactured homes can reduce construction time by 20 to 50 percent compared with site-built homes. As of 2024, Census data show that the average one-unit contractor-built home takes 10.6 months, whereas it can take up to 17 months with a multiunit home. This means that factory-built homes could put people into new homes several months faster, shaving off what could have been a year-plus-long wait down to a few months. With the housing shortage, the time advantage is not a mere convenience.  Reducing regulatory barriers like the chassis mandate can help expand the share of housing that moves off assembly lines and onto lots even faster.

Steel out, homes in

The permanent chassis requirement for manufactured homes has long imposed unnecessary costs and constraints on the industry. Most manufactured homes remain in place permanently, meaning the chassis adds little functional value while increasing construction costs by thousands of dollars per unit. By forcing homes to adhere to a transport-focused blueprint, the mandate constrains creative layouts, precludes certain foundation types, and limits placement on smaller or denser lots. Repealing the chassis mandate restores flexibility for developers and helps the industry respond to urgent housing needs.

In a bipartisan fashion, both the Housing for the 21^st Century Act and the Senate version of housing reform (the ROAD to Housing Act) include provisions to eliminate the chassis requirement. Removing the chassis requirement is a simple but effective way to expand housing supply, increase affordability, and strengthen homeownership pathways. The chassis requirement is a reminder that the housing crisis in the US is fundamentally a supply-side problem. The more the government can cut red tape in housing, the more the housing market can deliver affordable and high-quality homes to the American people.