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BACKGROUND 
     Field of Invention 
     This application relates to the off-site manufacture and on-site assembly of prefabricated dwelling units. Prefabricated dwelling units may be single, stand-alone Units, or individual Units within a group of Units such as a duplex, triplex, condominium complex or apartment building. 
     The construction of a conventional site-built dwelling unit is a multi-step process fraught with various pitfalls. Corruption, delays and damage are all but inevitable in a complex process involving multiple suppliers and trades that must be coordinated chronologically and simultaneously. The necessity to coordinate and work with different suppliers and skilled trades causes difficulty with scheduling, personnel conflicts, communication, and safety. The process can easily become lengthy, costly and inefficient. These multiple trades include but are not limited to: grading, sitework preparation, laying and pouring of foundations, framing, erection of structural walls, door and window cut-outs, roof construction, plumbing installation, electrical wiring, cat-5/network cabling, HVAC installation, alarm installation, laying of floors interior and exterior coverings, and final finishes and trims. These problems are inherent to the conventional site-built process when building locally with workers or other entities one is familiar with, and are magnified when building with workers one is not familiar with, or when building elsewhere than one&#39;s primary business location such as out of state or, especially, overseas. 
     Further, since each step is performed on-site, builders are forced to contend with a number of factors beyond their control. Inclement weather such as rain, snow, wind, heat, typhoons, hurricanes, blizzards, cold and other extremes can slow or halt construction, while ruining stored building materials before they are installed. 
     Meanwhile, the security of construction equipment and materials must be addressed as thieves or the trades&#39; own workers may often pillage construction sites by stealing valuable tools, equipment, and materials needed for the project. 
     SUMMARY 
     The shipping of prefabricated dwelling units may work within existing transportation system constraints such as road widths, bridge heights, and laws which inevitably vary from state to state and country to country. Towing a prefabricated dwelling unit down the road for a local delivery may be ideal over short distances, but this method is impractical for long distance shipment within the United States or overseas. One practical shipping method that is available is the use of existing standardized shipping containers which can be transported by sea, rail, or road to almost any location in the world. 
     However, the materials and components of an individual prefabricated dwelling unit do not fit within the confines of a standard shipping container in any of its available sizes unless either: a) the design of the prefabricated dwelling unit is severely limited to closely conform to the size of the shipping container resulting in a less desirable dwelling unit with substandard (less than 96″) ceiling heights; or alternatively if the amount of prefabrication is greatly reduced to enable more packing flexibility which significantly decreases the purpose of prefabrication. 
     In light of the foregoing, it would be most advantageous to have a dwelling unit that is not bound by the size, shape, and ceiling height of a standard shipping container, but can still be shipped in a single shipping container while maintaining a high degree of prefabrication. This configuration may maximize many of the advantages of prefabrication over site-built construction while maintaining much of the design flexibility of site-built structures. Moreover, it may minimize the costs and logistical troubles associated with long distance shipping and storage. 
     This application describes the off-site manufacture and on-site assembly of a prefabricated dwelling unit (“Unit”) that may be either a single stand-alone Unit or an individual Unit within a group of Units such as a duplex, condominium or apartment building. The Unit may be substantially prefabricated, having its walls, floors, and fixtures pre-installed. Further, the Unit that is configurable to a smaller size that may reside in a single shipping container along with all necessary components and tools for completion and installation of the prefabricated dwelling. For example, the Unit may fit in a single shipping container by nesting within itself through moveable walls and fold down floors attached to a flush flooring system. The Unit may fully reside in and may be loaded and unloaded from a standard single shipping container without limiting the size, shape, or aesthetics of the Unit. The Unit may include a high degree of prefabrication that requires minimal site-built assembly once delivered to the end user. The following integrated innovations allow a majority of the most time consuming and skill intensive tasks such as floor and wall framing, wiring, plumbing, fixture, and cabinet installation to be prefabricated and preinstalled into a Unit which may fit into a single shipping container, yet will not be limited to the size or shape of the shipping container. 
     This application describes a unique floor framing system and rollers, each of minimal thickness that maximizes the wall and ceiling heights of a Unit in relation to shipping container height. In one embodiment, the Unit may have a 96″ wall height. The Unit may also be configured to be shipped in a standard “High Cube” shipping container. The system may include a floor framing system comprised of metals or other suitably strong materials and a series of rollers, which may be removed from the Unit. These rollers protrude a minimal distance below the floor frame of a Unit. The rollers may permit a Unit to be rolled into or out of a container, or alternatively, rollers may be installed within the container floor protruding a minimum distance above the container floor to allow the same rolling function performed by the rollers when they are attached to the frame. The floor framing systems may further contain integral leveling bolts enabling the Unit to be rapidly leveled once placed on a site-built foundation, and/or integral tie-down devices to permanently secure the Unit in place on its foundation. The Unit may also contain integral foundation supports and/or soil screws enabling placement directly upon native soil as appropriate. 
     This application describes a Unit with preinstalled 96″ (e.g., 8 feet) tall walls. The capability to preinstall the walls means other interior components of the Unit such as cabinetry and bathroom fixtures, which may be installed against and connected into walls, may also be preinstalled. 
     This application further describes one or more expandable sections consisting of one or more foldable floor section(s) utilizing a unique hinge in this application or other means of allowing the foldable floor section(s) to be rotated into place along with one or more prefabricated, moveable exterior wall section(s). In an embodiment, the desired configuration is achieved by folding the Unit&#39;s folding floor section(s) down into place, removing the hinges, and then shifting the moveable wall section(s) into their respective foldable floor section(s) so that multiple sections of the house may reside within each other. 
     The moveable wall configuration process may include a linear movement of the moveable wall section(s) from the moveable wall section&#39;s shipping position on the main floor of a Unit out to a corresponding foldable floor section. The configuration may be further eased by various mechanisms in the design, which reduce the friction of a moveable wall section against the floor, such as small retractable wheels or rollers which may be removable wheels that are affixed to the bottom of a moveable wall section, or via an integrated air bearing system. In one embodiment, the moveable wall section(s) may be prefabricated prior to shipment including interior and exterior finishes so that internal wiring, plumbing, and other systems, once moved into final position, may be connected to corresponding adjacent systems in adjacent, non-moveable portions of a Unit. 
     The configuration capabilities of the Unit are a significant and unobvious advantage to the prior art as they enable a Unit of larger size and shape to be nested into a single shipping container for storage and shipping. The ability to utilize a single shipping container is advantageous, as a single container is simpler logistically, and substantially more economical than multiple containers. 
     Remaining components for completion of the Unit may include ceilings and roofs which may be securely stored in the empty shipping container until ready for use, minimizing risks of theft or damage from exposure to inclement weather. The components of the Unit may include prefabrication including panelization to be quickly assembled on-site depending upon the particular design of a Unit. Once the final components have been installed, the empty shipping container may be returned, or may be integrated as an attached or detached garage or other accessory structure to the Unit. 
     These and other objects and advantages of the present application shall be made apparent from the accompanying drawings and the description thereof. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention. The general description of the invention given above, and the detail description of the embodiments given below will serve to further explain and clarify the embodiments. 
         FIG. 1  is an illustration of the Unit loaded into a shipping container. 
         FIG. 2  is an illustration of a 1st story of a completed Unit. 
         FIG. 3  is an illustration of a 2nd story of a completed Unit. 
         FIG. 4  is an illustration of a Unit being unloaded from a shipping container. 
         FIG. 5  is an illustration of a Unit unloaded onto a foundation. 
         FIG. 6  is an illustration of a foldable floor section in final position. 
         FIG. 7  is an illustration of a moveable wall section in final position. 
         FIG. 8  is an illustration of the inside of a moveable wall section. 
         FIG. 9  is an illustration of a floor hinge with foldable floor section folded up. 
         FIG. 10  is an illustration of a floor hinge with foldable floor being folded down. 
         FIG. 11  is an illustration of a floor hinge with foldable floor folded down. 
         FIG. 12  is an illustration of rollers &amp; tie down devices. 
         FIG. 13  is an illustration of an integral cam lock and integral floor leveling device. 
         FIG. 14  is an illustration of framing inside an assembled Unit. 
         FIG. 15  is an illustration of a front view of an assembled Unit. 
     
    
    
     DETAILED DESCRIPTION 
     Overview 
     Following is a detailed description of the embodiments described in the application of the invention with reference to the accompanying drawings. The particularity of these drawings and their related description should not be construed as the only embodiments protected by the claims. 
     Illustrative Nested Structure 
     Referring to  FIG. 1 , numerals  1 ,  1   a  and  1   b  are the walls of the standard High Cube shipping container.  1   c  and  1   d  are separate wall sections affixed with hinges and a locking mechanism that forms the loading door of the shipping container. The longitudinal fixed walls  2  of the transportable structure may include the bathroom walls  2   b  and bathroom fixtures  2   c , the bathroom fixtures including bathtub, toilet and vanity. The fixed walls  2  may also include the stairs and supporting structure  2   d  and kitchen cabinets, granite counter tops, and related plumbing and fixtures  2   e . The fixed walls may be permanently affixed to the floor and frame assembly (reference numeral  9 , as seen in  FIG. 4 ). In this embodiment, the fixed wall section  2  may be prefabricated and complete with affixed concrete composite exterior siding, insulation, and interior gypsum wall board. Additionally, the fixed wall  2  may include electrical wiring and plumbing as well as a plurality of windows, one of which may be used as an emergency egress exit for a bedroom. Moreover, the fixed wall section  2  may include an installed electrically energized water heater  3 . Also, a hinged floor assembly  4  is shown in the shipping position and is fastened to the moveable wall section  5  which is also shown in its nested shipping position. The moveable wall section  5  may also be prefabricated with similar components as seen in the fixed wall section  2  with the addition of pre-hung exterior doors and the air bearing components illustrated in  FIG. 8 . Numerals  6 ,  7 , and  8  disclose areas within the fixed wall structure  2  and container  10  where setup and finishing materials may reside. The setup and finishing materials may include additional framing materials, insulation, exterior siding, steel roofing panels, garage door, miscellaneous fasteners, gypsum wall panels, floor decking, floor tile, paints and primers, appliances, and various decorative attachments secured for shipment. 
     Illustrative Assembled Unit 
       FIG. 2  is an illustration of a top view of the first floor of an assembled Unit. Stairs  3  provide access to a second story of the assembled Unit. 
       FIG. 3  is an illustration of the top view of the second floor of an assembled Unit which is accessible from the first floor via the stairs  3 . 
     Illustrative Steel Framework 
     As shown in  FIG. 4 , the frame  9 , depicted in cutaway view, may include welded steel tubing construction fitted with pressure treated floor decking on top of the frame  9 . Additionally, expandable foam insulation may fill the spaces between the steel frame tubes and the fixed wall section  2 . The container  10 , as shown with the loading doors  1   c  and  1   d  removed for clarity, may be guided by grease lubricated 1″×4″ wooden battens,  10   a . Rollers  26 , detailed in  FIG. 12 , may facilitate loading and unloading of the Unit structure. Further, integral cam locks  12 , integral floor leveling device  13 , tie down device  14 , the hinged assembly  16 , the moveable wall section  18 , the axle plate  29 , the square tube frame assembly  30 , and the floor joist  35  will be described below. 
     Illustrative Deployment from a Shipping Container 
       FIGS. 5 ,  6 , and  7  show the structure after deployment from the shipping container. The Unit may sit on the pre-poured concrete foundation  15 , in accordance with the local building jurisdiction and engineering specifications. The structure may be leveled using the integral floor leveling devices that will be discussed in  FIGS. 12 and 13  and may be fastened to the foundation as detailed in  FIG. 12  using Powers “power spike” fasteners. The hinged floor assembly  16  may be lowered to the foundation by unfastening moveable wall section  18  and carefully lowering it down to the foundation  15 . After the hinged floor assembly is placed on the foundation  15 , the hinges  17  may be removed by removing previously installed threaded fasteners. The hinged floor  16  may then be leveled using the integral floor leveling devices and may be fastened to the foundation using the Powers “power spike” fasteners detailed in  FIG. 12 . A compressed air source may be connected to airline  22  that is integrated into the moveable wall section  18 . The moveable wall section  18  may be moved into position using the compressed air as a lubricant as seen in  FIG. 8 . Once in position, the moveable wall section  18  may be fastened to the hinged floor assembly. 
       FIG. 8  illustrates the integral wall bearing which may include the standard sill plate and channel  46 , with a series of, in one embodiment, ⅛″ holes  19  that are drilled in a 3″×12″ grid ¼″ on center. Then, a steel cover plate and box  20  that is approximately 3¼″×13″×1″ tall with an open bottom may be welded and epoxied directly above the holes. The integrated wall bearing also may include an air inlet  21  connected to the cover plate box and an attached air source line  22  that provides compressed air through the moveable wall section  18 . For example, the air source line  22  may be routed to the next location (approximately 4′ on center) through the steel studs  23 , and may be connected to an identical section of the sill  18  by means of a T fitting. 
     Illustrative Hinge Action 
       FIGS. 9-11  illustrate the “action” of the hinge  24 . The hinge  24  consists of 4 pieces of punched steel and hinge pins  24   a  and may be configured to enable the hinged floor  16  to fold up perpendicular to the main framing and also to slide into the structure and sit squarely upon frame/floor section  25 . This configuration, thus, provides for loading of the shipping container without any obstructions. 
     Illustrative Framework 
       FIG. 12  illustrates the frame  9  in greater detail. The frame  9  may include a square tube frame assembly  30  with “c” channel floor joists  35 . A steel roller  26  and roller bearing assembly  27 , fitted in each end of the roller, may be attached to the square frame assembly  30  using the axle  28  and axle plate  29 . A spacer  31  may center the steel roller  26  on the axle  28 . The axle assembly may be mounted to project slightly below the frame to facilitate easy and relatively effortless loading and unloading of the unit from the shipping container. The frame  9  may also include a tie down device  32 , consisting of a strategically drilled steel plate containing the requisite amount of holes to precipitate the Power spike  33  installation. The “c” channel floor joist  35 , is also shown with a preformed tab  34 , and a welding rivet  36  attaching the floor joist  35  to the square tube frame  30 . 
     Illustrative Cam Lock Device 
       FIG. 13  has the integral floor-leveling device  37  which, in one embodiment, may be installed in the square tube frame  30  approximately 60″ on center longitudinally down each tube. The device consists of a nut  38  welded to the bottom of the square tube assembly  30 , a threaded bolt  39  that is screwed into the nut  38 , and an access hole in the steel tube frame directly above the welded nut  38 . Once the frame  30  is in the final assembly position on the concrete foundation  15 , the threaded bolt  39  may be adjusted utilizing a standard socket wrench and standard carpenter&#39;s level. Also shown in  FIG. 13  is the integral cam lock  40  which may include steel rod  41 , locking assembly  42 , and the oblong cam  43 . Once the structure is loaded in the standard shipping container the steel rod  41  may be rotated, which turns the oblong cam  43  into the shipping position. The oblong cam  43  bears on the inside of frame  30  as well as the wooden guide plate  44  that is positioned between the cam  43  and the container wall  45 . The oblong cam  43  secures the structure during shipment from unnecessary movement. Once the Unit is on site, the locking assembly  42  is unlocked, and handle  41  is rotated up to release the oblong cam  43 . 
     Illustrative Unit Construction 
       FIG. 14  depicts the steel framing of the Unit structure, with siding, insulations, and wall board removed for clarity. Once the moveable wall section  18  is affixed to the foundation the 2 nd  story of the Unit (in certain embodiments having two levels) is deployed. Pressure treated plywood decking or similar materials may be attached to the Unit floor using threaded attachment fasteners prior to installation of interior partition walls and related doors. The porch as well as the garage may be similarly deployed. The following describes the relatively small amount of finishing that may be used to complete the substantially pre-built Unit. The finishing materials may include ceiling insulation, vapor barrier, and steel roofing which are easily attached using supplied threaded fasteners. Electrical wiring is uncoiled and extended from the junction boxes located on the first floor fixed walls to the appropriate electrical junction box on the second floor. Supplied finishing materials may be applied and final paint may also be applied. On-site plumbing and electrical services may be connected through an access panel in the bathroom floor. Supplied cement based backer board may be applied to the pressure treated plywood flooring and ceramic tile may be installed throughout the structure. The exterior siding and decorative trim may be finished and coated with the included “stucco” coating and any decorative rock or stone (if applicable is attached. Lighting fixtures may be attached to pre-installed electrical pig tales. The rollup garage door may also be installed and the structure is ready for final inspection and occupancy. 
       FIG. 15  shows some examples of the finished product that may be stored in one container including two story house designs that may expand out of a single container. 
     Alternative embodiments may also include an air-bearing wall system and panelized components for the home. 
     Conclusion 
     Although embodiments have been described in language specific to structural features and/or methodological acts, it is to be understood that the embodiments are not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as illustrative forms of implementing the embodiments. For example, while embodiments are described having certain shapes, sizes, and configurations, these shapes, sizes, and configurations are merely illustrative.

Summary:
The off-site manufacture and on-site assembly of a prefabricated dwelling unit (“Unit”) are described herein. The Unit may be a single stand-alone Unit or an individual Unit within a group of Units such as a duplex or apartment building. The Unit is substantially prefabricated and nests within itself through a configurable design that utilizes a floor framing system. The Unit may also include fold down floor assemblies, moveable walls of 96″ height, pre-installed floors and fixtures. The Unit may be configured for a decreased footprint that will fit into a single shipping container along with the other necessary components for completion of the Unit on-site. The Unit may be loaded and unloaded from a single shipping container without substantially limiting the size, shape, or aesthetics of the Unit while being substantially prefabricated.