MARSHFIELD, Mo.–Mobile homes are less expensive than site-built houses, but it is more challenging to improve their energy efficiency, says a University of Missouri Extension natural resource engineer.

Many mobile homes have less insulation and lower-quality windows, says Bob Schultheis. Flat roofs and thinner walls make it difficult to add insulation.

However, the U.S. Department of Energy has identified some cost-effective energy conservation measures for mobile homes. These include sealing air leaks and furnace ducts; doing a furnace tune-up; blowing insulation into the home’s underside, or belly; installing interior storm windows; and blowing insulation into the roof.

“Doing a furnace tune-up and adding insulation to the belly or roof typically requires the skills of trained professionals,” Schultheis says. “But most homeowners can easily handle the installation of interior storm windows and sealing air leaks and ductwork.”

Before doing any weatherization, make sure all combustion appliances such as furnaces, stoves and gas water heaters are properly vented and in good working order, he says. Failure to do so could lead to the accumulation of dangerous amounts of carbon monoxide in your home.

Plug all holes around chimneys, vents, and water pipes with acrylic latex caulk or expandable foam from an aerosol can. Seal leaks in heating system ductwork with foil tape. Look for hidden air passageways in closets and cabinets and plug them. Caulk gaps around windows and doors and install foam gaskets under the plates of electrical outlets and light switches. Adding heat-shrink clear plastic on the interior of single-pane windows inexpensively increases their insulation value.

Schultheis also recommends installing a water heater insulation blanket and a low-flow shower head, and setting the water heater temperature to 120 F. If you have a forced-air furnace, clean or replace the filter monthly. For electric baseboard heaters, clean the registers weekly and make sure furniture doesn’t block the flow of heat to the room.

Schultheis says these homeowner-installed weatherization items should cost less than $100 and could cut your utility bill by 25 percent or more.