The most visible differences between manufactured and modular homes are the roof pitch, frame, foundation type, and inside walls.
A manufactured home typically comes standard with a 2/12 or 3/12 roof pitch. Modular homes typically come standard with a 5/12 or 7/12 roof pitch. Either type of home can be upgraded to a higher pitch for an additional cost.
Manufactured homes are built on a metal frame that is permanently attached to the home. The frame has tires and axles that are used for transportation. Once the home arrives on site, the tires and axles are removed when the home is installed on a permanent foundation. Modular homes are built with a wooden floor system, typically joists, and then transported on a reusable metal carrier. The home is lifted off the carriers by crane and placed on a permanent foundation.
Multiple types of foundations, at varying price points, are available for both manufactured and modular homes. A modular home must be installed on either a crawlspace or a basement.
The walls are typically constructed of poured concrete, hand-laid blocks, or prefabricated sections containing insulation. Manufactured homes can utilize either a crawlspace or a basement as well, but can also be installed on what is commonly known as “piers and skirting.” Pier footings are excavated with an auger and filled with concrete to ground level. The number of footings, positioning, and size of the footings are determined by a foundation print specific to the home. A vapor barrier is then rolled out underneath the entire home to control moisture, and blocks are placed on each of the concrete footings to provide a base, or pier, for the home. Once the home is resting on the piers, it’s brought to level and anchored to complete the installation. Skirting is available in a variety of styles and materials, most commonly vinyl or insulated panels, and is fitted around the perimeter of the home.
Manufactured homes typically come standard with vinyl gypsum paneling (VOG), however, some home series come standard with drywall.
If a home is part of a VOG series, it can be ordered with drywall for an additional fee. Modular homes come standard with drywall throughout. There is no option to build a modular home with VOG panels.
More Details on Manufactured and Modular Homes:
The term “manufactured home” was coined in 1976 when the HUD code was created by the US Department of Housing and Urban Development.
Upon implementing the HUD code, the term “manufactured home” was put into place to classify homes that were built to meet or exceed HUD code standards set for components such as electrical systems, fire safety, frame and body construction, thermal protection, and the ability of the home to be transported.
Before that time, single and multi-sectional homes had no standards to abide by, causing the homes’ quality to be inconsistent and sometimes unsafe. The proper term for homes built before 1976 is “mobile home”. The terminology is significant because it signals the construction standards, or lack thereof, that were used in building homes before implementing the HUD Code.
Modular homes are built to the same state and local building codes as site-built homes. They are not under the jurisdiction of the HUD code, and there is no specific set of modular codes that apply. Modular homes must comply with the applicable codes for the location where they are built, which is often based on the International Building Code.
An advantage to purchasing either a manufactured or modular home is that the construction of the units takes place indoors in a factory setting. This provides a greater level of control over the materials in both storage and construction. It also facilitates a lower price point in that materials are purchased in bulk, and the process is streamlined with multiple skilled trades housed in one location. In addition to the financial benefits of a climate-controlled production environment, third-party inspectors are on-site to verify the construction of the building as it moves through production.
Manufactured and modular homes are built to withstand the stresses of not only moving through the production process but also transportation. Homes may travel several hours in various weather conditions and speeds to arrive and potentially be lifted multiple feet in the air with a crane. This speaks volumes to the strength of construction and quality of the structure.
How Are Manufactured and Modular Homes Installed?
Once a manufactured or modular home arrives on site, there are several methods of setting the home on the foundation. It can be craned or rolled on a basement or crawlspace wall. If a manufactured home is being installed on piers, it will be parked on the footing pad and maneuvered into place with jacks. Regardless of the method used, once the home is installed on the foundation, the finishing work begins. The siding will be installed on the gable ends of the home, and shingles are completed at the marriage lines where the individual boxes, or units, come together. Any additional exterior setup such as installing screens and light fixtures, is done as well.
On the interior, the marriage line will either be finished with drywall or VOG panels, and any doorways that fall on the marriage line will be installed. Once this is complete, the trim will be installed in this area. Flooring will be merged at the marriage line, interior light fixtures will be hung, appliances will be unpacked, and any additional interior touch-ups will be completed.
In addition to the home itself, depending on your choice of foundation and upgrades, on-site construction of additional code requirements and customer add-ons will also be completed. This could include items such as skirting, steps, and decks at your entry doors, installation and connections of your utilities, basement steps and exterior basement entryways, HVAC components such as central air or a heat pump, gutters and downspouts, covered porches, or a garage. Once the entire project is complete, a final occupancy inspection will occur, and the homeowner will receive the keys to their new manufactured or modular home.