Dear EarthTalk:

How do manufactured homes stack up against traditionally constructed houses in terms of energy efficiency and overall environmental footprint?

Jen Jackson, via email

As one might expect, manufactured homes run the gamut with regard to energy efficiency. In an analysis completed by the American Council for an Energy Efficient Economy (ACEEE), it was found that modern manufactured homes used 70.4 MM btu/year, a significant amount less than the 108.5 MM btu/year average seen in traditional, or “site-built” homes.

In addition, the actual manufacture of manufactured homes produces much less waste, as does the on-site setup. According to the Manufactured Housing Association of British Columbia, the construction and set-up of manufactured homes creates 50 to 70 percent less waste than traditional home-building.

Traditional home-building also requires that the materials, tools and workers all be sent to different sites throughout the year. This approach is far less organized and efficient than the streamlined factory process associated with manufactured homes. As a result, all kinds of emissions are produced. In an in-depth report commissioned by the Sturgeon Foundation of Alberta, Canada, carbon dioxide (CO2) emissions of both modular and on-site building projects were compared. It was determined that the on-site construction process produced a whopping 43 percent more CO2 emissions!

According to ACEEE, those who lived in a manufactured home before 1976 “spent more money on their energy bills than on home loans” and spent double on energy per square foot than those who occupied a traditional home. How is this possible? Before 1976, manufactured homes were built more quickly, for less money and with far less regard for energy efficiency. By June of that year, the U.S. Department of Housing and Urban Development (HUD) devised and implemented the HUD Code, setting a higher standard in quality, safety and efficiency of product. 

Today, manufactured homes must have sufficient levels of insulation (this includes around ductwork, electrical outlets, lighting, etc.), modern water heaters and energy-efficient appliances. If the manufactured home does not meet the minimum standards set out by HUD, then it is illegal for it to be sold, leased or rented to anybody.

That being said, if you happen to own a manufactured home that was purchased before 1976, there are still many ways that you can upgrade your pad-from-the-past to meet the energy demands of the modern age. Passive solar design is one such avenue, whereby manufactured home-owners orient and design their home space to maximize the amount of sun exposure. This will not only power any solar panels that may have been installed more efficiently, it will also provide both natural light and heat. 

Using a solar water heater is another great way to reduce one’s energy expenditures. Though roof-mounted options may be limited (as manufactured homes are less sturdy), the ground-based options are definitely a good choice for anyone with a manufactured home that isn’t moved often. 

CONTACTS

• Comparison of Carbon Emissions of Modular and Site Built Houses, researchgate.net/publication/360173050_Comparison_of_Carbon_Emissions_of_Modular_and_Site_Built_Houses
• Mobilizing Energy Efficiency in the Manufactured Housing Sector, aceee.org/sites/default/files/publications/researchreports/a124.pdf.