Modular homes or pre-manufactured kits (see left photo: Shelter-Kit barn and pool) may be appealing because of lower costs and the speed with which the final product can be assembled, but what differences do they have when it comes to measuring how green a home might be.
On the positive side of the green scale, a few basics stand out: first, because of off-site manufacture of all wall and structural components, very little waste is created, especially when compared to a traditional stick-built home where it is common to fill five to seven 40-yard (8’ x 22’ x 8’) construction dumpsters that haul leftover debris to nearby landfills. Leftovers at the factory are usually recycled, or put to some other use in the finished home.
Second, the majority of prefabricated homes prove to be more energy efficient. Because they have been manufactured in a factory, this involves insulation and HVAC considerations. Manufactured homes commonly have insulation with R-values — the higher the number, the better the insulation — of 21 in the roof, 11 in the side walls and floor.
Most pre-manufactured homes come with Energy Star rated appliances and heating systems. Energy Star homes are often 20 to 30 percent more efficient than traditional homes. In addition, low “E” window packages help contribute to a tighter building envelope.
Third, indoor environmental air quality is considered before putting together the entire package.
Genesis Homes, this nation’s largest modular homebuilder (see left photo), believes in strict adherence to a green standard. “As the Nation’s largest modular builder, we have chosen to adhere to the National Association of Home Builders (NAHB) Green Standard. This standard provides you with third-party certification that the modular home you are purchasing can deliver on its claims of energy efficiency and resource conservation.”
Are there any negative considerations regarding the green perspective? Maybe only the amount of fuel required to deliver the unit to its final destination. But in a traditional stick-built home, even more petroleum is required for the many materials deliveries for all subcontractors involved – carpenters, roofers, insulation, HVAC, electric, etc.
As the world and its urban areas grow more congested and material supplies wane, modular homes and kits appear to be options that deserve serious exploration.