The Factory/Manufacturer
Modular Homes are built in a factory setting where raw materials and design and assembly personnel are brought together in a controlled environment to create a finished product.  Construction within a factory eliminates the possibility of damage from weather and allows all materials to be assembled in a protected climate-controlled environment.  This is important given the recent problems with mold as it eliminates the possibility of any water infiltrating the house during construction.

The Builder/Seller/Contractor
The modular manufacturer does not sell directly to the homebuyer.  Instead, homebuyers purchase a modular home from a modular builder, who is responsible for working with the buyer to determine the type and design of home they want.  The modular builder then orders the home from the manufacturer.  The modular builder is not an agent of the manufacturer, but an independent business owner.

Customization
As mentioned in the previous paragraph, the builder and manufacturer will work with the homeowner to determine the type and design of modular home that best suits the purchaser’s needs.  Home purchasers are unlimited in the style and size of the home they can have built.  These homes are totally customizable and no two homes are the same.

Construction & Plan Review
Before a modular manufacturer begins construction, all building plans must be reviewed and approved in each state where the manufacturer intends to sell homes.  Homes must be designed and built to the code for the state where the home will be shipped for final location.  The manufacturers contract with state approved third party plan review agencies which conduct plan review on behalf of the state.  The modular manufacturer also contracts with a third party inspection agency that is licensed by the states to perform the in-plant inspection while the home is in production.  When the housing sections or modules are complete, the third party places a label on the home certifying that the home has been manufactured in conformance with approved plans and complies with all provisions of the building code.

Shipping & Stability
After construction in the factory the separate modules are loaded for transport.  To deal with the rigors of shipping, each modular home has been constructed with roughly twenty to thirty percent more materials than a traditional stick-built home.  (For example, drywall is typically glued with special adhesive and then screwed to the framing).  These additional materials greatly increase the structural strength of the home as noted in a recent FEMA study on 1992’s Hurricane Andrew. 

Final Assembly
After the builder orders the home from the manufacturer, in most cases the manufacturer will give the builder specifications for the foundation.  The builder is then responsible for preparing the foundation for the modular home.  When the home is constructed, it is shipped to the home site.  The following day, a crane is used to place the home modules on the foundation and set the roof in place.  By the end of the day, the home has been completely installed and is closed up and secured to the foundation.  In the subsequent weeks, the builder will finish the home.  The finish work includes securing any remaining roofing shingles, attaching siding and finishing some interior drywall work.  Generally, the home is ready for occupancy within several weeks.  Prior to moving in, a local building code inspector will make a final inspection and issue an occupancy permit