Abstract:
Transportable steel module units and methods for assembling such units to form structures on site to create living and workspace building environments which are non-combustible and resistant to unhealthy contaminants, and high winds and other environmental conditions and wherein each module unit is substantially completely prefabricated and finished to permit immediate occupancy and predetermined use of a structure created by connection of two or more module units.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]    This application is based on and claims benefit of U.S. Provisional Application No. 60/171,310 filed Dec. 21, 1999 in the name of the same inventors and entitled RELOCATABLE FIRE, STORM AND CONTAMINANT RESISTANT MODULAR BUILDING STRUCTURES. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    This invention is generally directed to transportable and relocatable building structures and more particularly to such structures which are fabricated from metallic and preferably steel materials and which are formed of modular units which are substantially completely prefabricated and finished such that they are ready for use when assembled on site. The invention is further directed to the field of transportable and relocatable modular building units which are readily assembled to provide contaminate free, weather resistance and fire proof structures which are safe for numerous work space and/or living environments including, but not limited to, temporary classrooms.  
           [0004]    2. Brief Description of the Related Art  
           [0005]    Temporary building structures are used not only for emergency residential or other housing purposes after natural or manmade disasters, but are also used for providing working space or educational space in the form of temporary classrooms. Conventionally, many temporary building structures are fabricated on site or are assembled from modular wooden structures which must be finished on site. Such temporary buildings thus require that appropriate building materials, including structural as well as finishing materials, be appropriately supplied to the site for assembly and/or installation by skilled workers. Not only does site construction require on site engineers, but it also requires appropriate construction technicians to provide for the construction of an outer shell forming the temporary structure as well as skilled individuals for installing and connecting heating and air-conditioning, sources to control the environment of such temporary structures, electricians to install and connect necessary wiring circuits for all electrical purposes which may include not only normal electrical outlets but specialized outlets for purposes of communication including computer, television, audio and other types of communication, plumbing personnel for installing and connecting appropriate sources of water supply and/or waste water disposal, depending upon the contemplated use of a temporary structure.  
           [0006]    In view of the foregoing, not only does on site construction require that each component of a structure be accurately supplied to the construction site, but, each component must be properly identified and placed into service in an appropriate manner to insure both structural integrity and operativeness of a structure. Frequently parts of systems such as electrical circuits and assembly components may be missing or misplaced during construction thereby necessitating a delay in the construction process and also increasing the overall cost by requiring that replacement parts be provided by special couriers to the construction site. Such construction problems relating to improperly supplied or missing materials and improper use of components in an on site construction may result in unacceptable delays or in unsafe building structures being placed into use.  
           [0007]    In addition to the foregoing, there are other problems inherent with on site construction of temporary living and working spaces. By way of example, during construction of an on site building, weather conditions and building methods allow moisture and other external contaminates to penetrate into interior components of the building structure which contaminates can create an unhealthy living environment. Once a structure is completed, molds and mildews may develop within floors, ceilings, and wall panels resulting from such ambient conditions and contaminants. Inappropriate assembly of panels to substructures can result in allowing contaminates to enter spaces in walls, floors and ceilings resulting in the growth of mold, mildew and bacteria which can affect the health of individuals utilizing such structures.  
           [0008]    Further, many on site temporary building structures are not adequately designed to provide a safe environment for those who are to be sheltered therein. By way of example, many temporary or relocatable buildings are constructed of materials which are easily or readily combustible thus making them potentially unsafe and unsuitable for many uses. Further, conventional temporary transportable or relocatable buildings often are subject to damage by high winds, rains, and other weather or ambient conditions thus further making them unsuitable for many uses.  
           [0009]    Temporary building structures which are relocatable or which are designed to be assembled from component parts on site are frequently used as temporary classrooms. In such environments, children are subjected to the adverse affects associated with conventional structures, making them undesirable and unsafe. Even with this in mind, however, many jurisdictions utilized higher risk portable or relocatable classrooms due to economics and restrictions associated with expanding permanent school facilities. Often school enrollments will increase faster than a jurisdiction can predict, resulting in a lack of classroom space and/or lack of funds to provide permanent space for all students.  
           [0010]    By way of example, many temporary classrooms or other work space environments are created using transportable modular units constructed in the same manner as mobile houses. Mobile home structures are not designed to withstand harsh environmental conditions such as high winds and are not fireproof or contaminant resistant. Even when securely anchored, mobile home type structures are easily damaged and destroyed when subjected to tropical force winds. In view of the foregoing, mobile home structures are not suitable for providing a safe temporary classroom or other temporary working enclosure.  
           [0011]    In view of the foregoing, there remains a need to provide relocatable and transportable structures which can be placed into use with minimum assembly and at reasonable costs. In addition, there is a need to provide for transportable and relocatable structures to ensure a healthful and safe environment free from contaminates, which are fire proof, and which are resistant to damage from high wind and other environmental conditions.  
         SUMMARY OF THE INVENTION  
         [0012]    The present invention is directed to transportable and relocatable building structures which are formed of prefabricated modules and wherein preferably two or more modules are assembled on site to form a completed habitable structure suitable for use as a temporary classroom for students as well as other uses. The invention is more specifically directed to modular building units which are formed having metal, and preferably steel, inner and outer wall panels, floors and ceiling components and having suitable insulated space created therein in which both thermal and sound insulation are provided in such a manner as to prevent intrusion and build-up of moisture and to prevent growth of undesirable and unhealthy contaminants including molds, mildews and bacteria. Each modular unit is prefabricated to include all necessary electrical, communication and plumbing components with each of the components being oriented, in a preferred embodiment, so that when modules are assembled, they can only be assembled in a particular manner to ensure proper alignment and connection of all such electrical, communication and plumbing components so that the operativeness of each electrical, communication and plumbing system including air conditioning and heating systems, is ensured. Therefore, the only requirement for trained technicians and electrical, plumbing and other inspections is for connecting exterior connection of sources of electrical, plumbing and communication equipment to a control panel associated with a completed building structure.  
           [0013]    In the preferred embodiment, each modular unit of the invention includes steel reinforcing to ensure that the floor, ceiling and wall panels associated therewith are hurricane and high wind resistant. Further, the thermal and sound insulation provided in each wall, ceiling and floor panel is positioned and structured to prevent any moisture build-up. In the preferred embodiment, the interior wall panels are perforated in order to provide for good sound attenuation.  
           [0014]    To assist in preventing outside contamination, each building structure formed by an assembly of modular units of the present invention is heated and/or air conditioned by a central unit mounted thereto. The area above the ceiling of the structure may function as a chamber for the intake associated with such heating and/or air conditioning units. Appropriate filters including electrostatic or HEPA filter elements may be incorporated to provide air purification and removal of harmful bacteria or other contaminants which may gain access to the interior of the structure through the normal use of doors and/or windows provided in each assembled structure and the intake of fresh, make up air. Because of the air tightness of the structure, an exhaust system is incorporated into the HVAC system to maintain a predetermined positive pressure within the structure to balance the fresh intake air and the exhaust air through the windows, doors and to maintain the required air exchange.  
           [0015]    To provide a fire proof or non combustible environment, the panels of each modular unit contain no flammable or readily combustible materials. Metal flooring associated with each modular unit may be selectively coated with a non-skid coating of a non-combustible material or may be covered with an appropriate carpeting which is specifically designed for fire resistance.  
           [0016]    As the roof structures of the modular units of the present invention are also formed of a metal and preferably steel material, the exterior surface is coated with a microsphere coating. Such coatings are highly energy reflective thus preventing build up of heat within the interior of a completed structure. In some instances, depending upon climatic conditions, the side walls of the modular units may also be coated with the reflective material.  
           [0017]    In the preferred embodiment, door and window units are installed during the prefabrication process with the interfaces between adjacent wall components being appropriately sealed in an air tight relationship with respect to one another to prevent contamination of the structural units. Modular units which are connected on site include outer overlapping trim strips which provide for air and water tight seals therebetween or, in the alternative, such abutment joints may be welded on site in some applications.  
           [0018]    To further prevent damage from environmental conditions including high winds and hurricanes, the structural units of the present invention are provided with appropriate exterior elements for mounting protective barriers such as solid panels or plywood or other materials for purposes of covering windows associated with some of the modular units.  
           [0019]    Each modular unit also includes mounting structures for securing the modular unit to support pads which are preferably formed of concrete or steel ties which have been appropriately anchored in the soil to provide a strong base for supporting the structural units when assembled.  
           [0020]    The modular units of the present invention may be mechanically connected utilizing conventional fasteners such as bolts and screws or may be connected utilizing a variety of snap fit connectors which are installed during manufacture of each prefabricated unit such that by properly orienting and positioning one modular unit adjacent another modular unit, the movement of the units together will simultaneously cause or effect connection of the fastening elements in much the manner of a quick disconnect fitting of the type utilized in pneumatic circuits and other quick disconnect couplings.  
           [0021]    It is the primary object of the present invention to provide prefabricated modular building units which are substantially completely constructed at an assembly location such as a manufacturing facility under controlled conditions to include both exterior and interior components such that when delivered on site, the assembly of two or more modular units to one another forms a substantially completely occupiable building which may be utilized for substantially any purpose. Further, connection of exterior sources of electricity, communication lines and/or plumbing fixtures is effected by single exteriorly accessible connections such that on site inspection of interior wiring and plumbing including electrical and communication wiring is not necessary.  
           [0022]    It is also an object of the present invention to provide modular units which may be assembled to form complete and immediately usable work, living and teaching space where the overall structure can be assembled on site by connecting only the modular units with respect to one another such that inventory of interior and exterior component parts is not required as such parts are installed prior to on site delivery.  
           [0023]    It is also an object of the present invention to provide modular transportable building structures which may be suitable for use as classroom environments and which are substantially fire proof, storm proof, including high winds and rains, and contamination proof, including free of bacteria, mold and mildew.  
           [0024]    It is yet a further object of the present invention to provide modular units which may be assembled on site with a minimal work force and yet provide a rigid, sturdy and healthful environment suitable for a plurality of work and living uses including uses as classroom environment and wherein the structures may be erected at a substantial economic savings thereby reducing the economic burden to expand living and work space environments for the benefit of creating more beneficial work, living and educational space without over crowding.  
           [0025]    It is yet another object of the present invention to provide modular building units which are formed of steel panels which are uniformly constructed and specifically designed to be interconnected to form usable enclosed work and living space and which are transportable over conventional highways from a point of manufacturer to an assembly site.  
           [0026]    It is also another object of the present invention to provide modular building units which can be assembled to provide single level working or living space and which can also be assembled in stacked relationship to provide multi-tiered working and living environments.  
           [0027]    It is also an object of the present invention to provide readily assembleable modular units which are fully fabricated in order to provide immediately useful, healthful and safe environments wherein each modular unit is designed so as to be maneuvered utilizing conventional hoisting and lifting equipment such as forklifts and cranes. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0028]    A better understanding of the invention will be had with reference to the attached drawings wherein:  
         [0029]    [0029]FIG. 1 is a front perspective view of a building formed utilizing the transportable modular building units of the present invention;  
         [0030]    [0030]FIG. 2 is a view taken from the left side of the building of FIG. 1;  
         [0031]    [0031]FIG. 3 is a view taken from the right side of the building of FIG. 1;  
         [0032]    [0032]FIG. 4 is a front plan view of the building of FIG. 1;  
         [0033]    [0033]FIG. 5 is an enlarged cross-sectional view taken along line  5 - 5  of FIG. 1;  
         [0034]    [0034]FIG. 6 is an enlarged partial cross-sectional view taken along line  6 - 6  of FIG. 1;  
         [0035]    [0035]FIG. 6 a  is an enlarged cross-sectional view showing a roof joint connection in keeping with the embodiment shown in FIG. 6;  
         [0036]    [0036]FIG. 7 is an enlarged cross-sectional view taken along line  7 - 7  of FIG. 1;  
         [0037]    [0037]FIG. 8 is a top floor plan view illustrating an internal finishing of the building shown in FIG. 1.; and  
         [0038]    [0038]FIG. 9 is a view similar to FIG. 8 showing electrical connections.  
     
    
     DESCRIPTION OF PREFERRED EMBODIMENT  
       [0039]    With continued reference to the drawing figures, a building is shown as constructed from a plurality of modular units in accordance with the teachings of the present invention. The building shown includes opposing outer modular units  21  and  23  and a central modular unit  22  which are shown in the drawings figures as assembled in side-by-side relationship to form a free standing temporary classroom. Although the invention will be described with respect to the three modular units shown in the drawing figures, the present invention is operative with respect to one or more modular units and particularly to at least two modular units which are designed to be connected on site to form a completed and habitable building structure. In addition, although a temporary classroom is disclosed in the drawing figures, the modular units of the present invention can be utilized to form any type of residential, commercial, recreational or other type of building. The building when assembled includes a front wall  24  including at least one entry/exit door  25  and windows  26 , a rear wall  28  and opposite side walls  29  and  30 . Doors and windows may also be provided in the rear and side walls. The front, rear and opposite side walls are primarily formed of metal, preferably steel.  
         [0040]    With particular reference to FIGS.  1 - 3 , it should be noted that the side walls are formed by joining the modular units such that each side wall is segmented including sections  29 A,  29 B and  29 C and  30 A,  30 B and  30 C. As shown in FIGS. 8 and 9 the completed building also includes a metallic and preferably steel floor  32  which is formed by interconnecting floor segments  32 A,  32 B and  32 C associated with the modular units  21 ,  22 ,  23 , respectively. The upper or interior surface of each of the steel floor segments  32 A- 32 C is preferably covered with a sheet vinyl, or a polyurethane coating which is skid resistant or with a fire retardant carpet or other appropriate fire retardant material.  
         [0041]    The completed building also includes a metallic, preferably steel, roof  34  which is formed by interlocking or interconnected roofing plates  34 A,  34 B and  34 C associated with the modular units  21 ,  22  and  23 . Although the roof may be formed relatively flat, in the embodiment shown in the drawing figures, the central section of the roof  34 B has a mid-upper apex  35  from which the roof slopes downwardly on opposite sides thereof along the width “W” of the building. Roofing segments  34 A and  34 C also are shown in the embodiment of the drawing figures as tapering downwardly toward the front and rear walls of the building. The roof is reinforced by providing box or tubular steel or other metallic beams  36  and  37  along each longitudinal edge portion of the central roof section  34 B and by providing similar beams  38  and  39  along the longitudinal inner edges of roofing sections  34 A and  34 C, respectively, as shown in FIGS. 5 and 6. As opposed to box or tubular beams, other cross-sectional rigid support steel beams, such as I-beams, may be utilized in keeping with the teachings of the present invention. To assembly the roofing sections, bolts  40  and associated lock nuts  41  are inserted through aligned openings (not shown) in the reinforcing beams at spaced points along their length. As opposed to utilizing conventional fasteners such as bolts, the reinforcing beams may be welded or otherwise secured with respect to one another. In some embodiments, latching male and female couplers may be utilized between each of the opposing beams  36  and  38 ,  37  and  39  in order to secure the roofing sections with respect to one another. Such devices may be quick disconnect couplers allowing the separation of the couplers on the release of appropriate locking mechanisms associated therewith.  
         [0042]    With specific reference to FIG. 6A, the opposing edges of each of the roofing sections  34 A,  34 B and  34 C are either upturned or down-turned, such as shown at  44  and  45  for roofing sections  34 A and  34 B, and are spaced with respect to one another a slight distance in order to receive a weather seal  46  therebetween. Each weather seal  46  extends the full length of the joint between the roofing sections thereby ensuring that no air or moisture can enter an air space  50  defined between a ceiling  52  of the completed building and the roof sections  34 A,  34 B and  34 C. Each of the roofing sections  34 A,  34 B and  34 C is further reinforced by a plurality of generally laterally extending metallic, preferably steel, channel roof stiffeners  54 . The number and spacing of the roof stiffeners  54  will depend upon the effective length of the modular units. In some embodiments, the roof stiffeners  54  may include a plurality of spaced openings  55  therein in which suspension rods or wires  56  preferably formed of metallic material, are selectively mounted for purposes of supporting generally inverted T-shaped suspension grids  58  of a grid system for supporting the ceiling structure  52 , as will be described in greater detail hereinafter.  
         [0043]    To reduce the effect of thermal radiation on the completed building structure, each of the steel roofing sections is coated with a reflective coating or paint preferably of a type containing microspheres. Such a coating or paint is manufactured and distributed under the name Ultra Seal distributed by Nationwide Chemical Coating Mfg., Inc.  
         [0044]    To further insulate the roofing area or air chamber  50  associated with the completed building of the present invention, each roofing section includes a thermal insulation layer  60  which extends substantially along the entire inner surface thereof. A preferred insulation is AstroFoil™ manufactured by Innovative Energy, Inc. The roofing sections further include additional thermal batt type insulation  62  which extends along the complete lower surface area defined by each section and above the ceiling structure  52 . In this manner, the thermal insulation layers  60  and  62  are spaced from one another so as to define the area or air chamber  50  therebetween. Further, and as shown in FIG. 6, the area  50  within the roof section  34 A is in open communication beneath the reinforcing beams  38  and  36  with the area  50  of the central roofing section  34 B and, in a like manner, the area within the central section is in open communication with the area  50  within the roofing section  34 C for purposes of providing uniform air flow to or from a central air distribution, heating, and air conditioning unit  65  which is mounted to an exterior wall of one of the modular units of the building. In the drawing figures, the air circulation unit  65 , which includes heating and/or air conditioning capabilities is mounted to the side wall  30  of the structure and is supported on the side wall member  30 B associated with the central modular unit  22 . The air circulation unit  65  is mounted exteriorly of the building structure so as not to adversely effect occupiable space within the interior of the building. The air circulation, heating and air conditioning unit  65  may also include a fresh air intake  66  which allows air from outside the building to be selectively introduced into the interior after passing through a filter element  67  which may be an electrostatic filter or HEPA filter capable of removing possible contaminants which could effect the health of individuals within the structure. The operating capacity of the air circulation, heating and air conditioning unit in cubic feet per minute will be determined by local code such that the air maintained within the completed building structure is healthful.  
         [0045]    With specific reference to FIG. 7, an enlarged cross-sectional view having portions broken away of a corner portion of modular unit  21  is disclosed. It should be noted that the cross-sectional characteristics of the rear wall  28  and the opposite side wall  29  of the completed building wall have the same structural characteristics.  
         [0046]    Each of the outer modular units  21  and  23  include corner columns  72 A and  72 B which are shown in the drawings as being open steel columns. It should be noted that other types of steel columns may be utilized in keeping with the teachings of the present invention. Each of the steel columns  72 A and  72 B is welded or otherwise secured at its lower end to the steel floor section  32 A which section is welded to a steel frame or beam  74 A which extends along the front of the building as shown in FIGS.  2 - 6 . A similar beam  74 B extends along the rear of the building. The floor beams are also formed of steel which may be hollow in cross-section or may be formed as an I-beam, channel beam or similar structure. The support beams  74 A and  74 B are interconnected at their ends to side support beam segments  75 A and  75 B, respectively, which extend along each side of the modular units  21  and  23 . The center modular unit  22  includes a pair of spaced vertical support posts or columns  76 A and  76 B at each end thereof which are formed of similar material as the corner columns  72 A and  72 B. The columns  76 A and  76 B are welded or otherwise secured to a support beams  77 A and  77 B provided at each side or end of the modular unit. Each of the outer modular units also includes along the side walls thereof interior vertical support columns or posts  78 A and  78 B, respectively, which are formed of steel similar to columns  72 A and  72 B.  
         [0047]    To join the posts or columns  78 A and  78 B to the columns  76 A and  76 B, respectively, a plurality of mounting brackets  80  may be welded or otherwise secured to an interior surface of one of each pair of columns to be connected. In drawing FIG. 7, the bracket  80  is shown as being secured to column  78 A, however, the bracket could be secured to column  78 B. In a like manner, a further bracket  81  is welded or otherwise secured to column  76 A. Again, the bracket  81  may be provided along the interior surface of the column  78 A if the bracket  80  is attached to the column  76 A. The two brackets have aligned openings therein for receiving conventional bolts  82  for securing the brackets together and thus retaining the columns  78 A and  76 A in assembled relationship. The number of brackets provided along the vertical length of the columns may be varied depending upon the anticipated size of the building. In a preferred embodiment, the brackets  80  and  81  are provided in the ceiling area such that the connections are not visible along the interior space of the building.  
         [0048]    To seal the connection between adjacent columns of the modular units, snap-on generally unshaped covers  85  are provided. The covers will prevent the passage of air and moisture between the columns as well as between the columns and adjacent segments of the walls associated with each of the modular units. In some embodiments, the covers may be welded or otherwise secured and formed of a metallic material whereas in other embodiments, the covers may be formed of a different material which is suitable for preventing the passage of moisture or air into the areas between the columns.  
         [0049]    Seals may also be incorporated on the surfaces of each roof, floor and wall column whereby when the modular units are drawn together and connected, the seals compress together against the surfaces of the columns and beams to effect a moisture tight seal.  
         [0050]    Each of the walls of the modular units of the present invention are defined having outer steel wall panels  86  which may be corrugated as shown at  87  for purposes of reinforcement and strength and inner metallic and preferably steel panels  88  which may include a plurality of generally equally spaced elongated recesses or grooves  89  formed therein. Each of the outer wall panels  86  is welded or otherwise mounted and sealed with respect to one of the vertical support columns such as shown in  72 A or to columns providing a frame for one or more windows or one or more doors, as will be described in greater detail. Mounted interiorly of each outer steel panel  86  is a thermal insulation barrier  90  which substantially covers the entire interior surface of the outer wall panels. The preferred type of thermal insulation is Astrofoil™. Spaced inwardly of the thermal insulation layer is a sound attenuation batt insulation material  91  such as manufactured by Eckel Industries, Inc. Spaced inwardly of the sound insulation layer  91  is a vapor barrier  92  which extends substantially along the entire inner surface of the wall panel. A plurality of vertically spaced horizontal steel angles  94  extend along the length of each wall segment and provide a flange for receiving fasteners  95  which are used to secure the inner steel wall panels  88  relative to the exterior wall panels  86 . The angles are appropriately secured such as by welding to the outer wall panels. The fasteners  95  are preferably driven through the grooves  89 .  
         [0051]    One of the unique features of the present invention is that the wall structures are formed of outer and inner steel panels and are both insulated for thermal protection as well as for sound attenuation. Further, the outer steel wall panels form a barrier which will prevent moisture from entering insulation materials such that, when the walls are fabricated in a controlled environment within a factory and the modules are assembled on site, the outside walls are impervious to moisture and other contaminates. Once the inner wall panels are sealed with respect to the outer wall panels and because of the steel construction, contaminates can not enter the space between the inner and outer wall panels thereby preventing mold, mildew or other bacteria growth within the walls. Further, with the present invention, the wall structures, as well as ceiling and floor structures can be manufactured in a controlled factory environment before delivery to an assembly site. Such finishing of the wall units is not possible when manufacturing a temporary building on site or off site by conventional means.  
         [0052]    With reference to FIG. 5, the interior steel wall panels  88  may be provided with a plurality of small openings  100  therein. The interior panels are perforated so as to provide sound attenuating characteristics so that sound waves can not be reverberated within the steel structure. The size and type of openings  100  may be varied and be within the teachings of the present invention; it being the specific purpose to provide surface characteristics for the wall panels which will attenuate sound without the use of combustible type materials.  
         [0053]    In some embodiments, and as previously discussed, the outer surface of the outer panels  86  may be coated with a radiation reflective coating which may include a coating such as described with respect to the roof panels.  
         [0054]    With specific reference to FIGS. 5 and 6, partial cross-sectional views are shown showing the manner in which one of the window units is installed with respect to the front wall of the modular unit  21  of the present invention. The window is completely framed by hollow steel, aluminum or other metallic framing  101 . The outer metal panels  86  of the wall are curved inwardly adjacent to the frame  101  to provide a welding surface or connection. Inwardly depending steel angles or flanges may be utilized for providing support for the internal insulation associated with the walls of the modular unit and/or for connection of the inner wall panels  88 . A trim member may be welded or otherwise secured about the interior portion of the window frame  101  for providing a finishing joint between the inner steel panel  88  and the window.  
         [0055]    In drawing FIG. 1, four windows  26  are shown mounted in side-by-side relationship within the window frame  101 . The type of windows may vary and yet remain within the teachings of the present invention. For purposes of illustration only, the windows  26  may include crank mechanism  110  which allows the windows to be pivoted so as to open. To provide protection to prevent window damage in the event of high winds, such as hurricanes or tornados, opposing L-shaped flanges  114  and  115  are provided along the upper and lower portions of the outer area of the window frame  101 . The flanges are spaced a distance from the front surface of the window assembly  26  to allow an appropriate solid barrier to be slidingly or otherwise positioned therebetween. In one embodiment, plywood panels may be slidingly engaged in opposing channels  118  and  119  defined by the flanges  114  and  115  and the interior surface of the window  26 . Permanent roll down or other types of window protection can also be provided.  
         [0056]    With specific reference to FIG. 6, it should be noted that the outer wall panels  86  are designed to extend upwardly into substantial contact with a steel angle to which the steel plate roof panel is attached so as to be substantially sealed with respect thereto. A generally L-shaped trim strip formed of steel trim angle  120  is shown which is used to seal the roof panels and the upper portion of the outer wall panel. It should also be noted that the thermal barrier  90  extending within the wall is preferably coextensive with the thermal barrier  60  extending in the roof portion of the modular units in order to form a continuous barrier.  
         [0057]    With particular reference to FIG. 7, at least one door  25  is provided into the building. The door is surrounded by a steel frame  124  which is welded or otherwise secured to the inner and outer wall panels  88  and  86  so as to eliminate the flow of ambient air and moisture therebetween. Appropriate seals may be provided along the edges of the door frame to restrict air flow between the door  25  and the door frame. The door is suspended by appropriate hinges (not shown) from the door frame  124 .  
         [0058]    One of the unique features of the present invention is that the modular units  21 - 23  are substantially fully finished at the point of manufacturer such that when assembled on site, not only is the resultant building readily habitable but the utilities associated therewith including electrical, plumbing, communication and the like are substantially ready for connection to external inputs and outputs. In this manner, all internal electrical wiring, plumbing and communication cables and equipment is pre-installed or pre-wired within each modular unit requiring only quick connect couplings to be made between electrical conductors, pipes, and communication cable. By pre-installing all internal wiring, ducting and plumbing, there is no need to require a plurality of separately skilled technicians to be on site during the erection of the modular units to form a completed structure. Further, there is also no requirement to halt building assembly in order to allow for local inspections as such inspections may be made at the factory during the fabrication of the modular units. This facilitates not only the time of construction but also reduces the cost of construction by enabling those on site to preform their work without interruption.  
         [0059]    To facilitate the manner in which the utility wiring and plumbing is connected, the present invention, in a preferred embodiment, purposes that all connections be polarized. That is, each electrical conductor, communication cable or wire and plumbing pipe includes a connector which is designed to be joined to a connector of an adjacent modular unit when the units are placed in assembled relationship. Further, the connectors are designed such that the connectors are only cooperatively mated with respect to one another in the event the modular units  21 - 23  are properly aligned. As shown in FIG. 7, and by way of example, electrical conduits  132  for providing power to conventional outlets  130  disposed at spaced locations within each modular unit extend through the walls defining modular unit  21 . At the end of the conduit  132  is a first male connector  134  having appropriate positive, negative and ground leads associated therewith. When the modular unit  21  is to be joined on site with modular unit  22 , the male connector  134  is selectively receivable within a female connector  136  provided within the modular unit  22  and which itself is connected to an electrical conduit  138  extending through and communicating with additional electrical outlets in that modular unit. Electrical connector  136  can only receive the electrical connector  134  if the modular units are properly aligned thus ensuring the correct polarity of all electrical connections during assembly.  
         [0060]    As shown in FIG. 7, the electrical connector  134  of modular unit  21  and the electrical connector  136  of modular unit  22  are installed within the columns of each modular unit, however, such connectors may be provided within the area of the ceiling or in an area beneath the floor. However, it is preferred that all electrical, plumbing and communication connections be polarized to ensure that connections can only be made in a proper manner.  
         [0061]    Although not specifically shown in the drawing figures, where plumbing pipes are to be connected through the walls of the modular units of the present invention, quick disconnect and sealed couplings will be utilized. Each coupling will include a male connector and a female connector with appropriate seals being provided therebetween, such that when the connectors are assembled, a fluid type connection is established therebetween.  
         [0062]    The modular units of the present invention may also be pre-wired for communication purposes. In this respect, telephone, cable and other type of wiring may be provided in each of the walls of the modular units and in much the same manner as described with respect to the electrical wiring. This allows connection to television cable and telephone wire for purposes of telephone and internet connections, cable for communication with communication systems such as public address systems utilized in various institutions including schools, and direct fire reporting communication and the like.  
         [0063]    With specific reference to FIGS. 5 and 9, an example of an electrical and communication wiring hook-up for the building shown in FIG. 1 is disclosed. It is noted that a plurality of 120 volt quadruplex electrical outlets  130  are provided within the interior of the assembled building. Also provided is a TV cable connection  140 , a public address speaker  142 , a fire alarm  144 , a fire pull station  145  and a telephone line connector  146 . Also provided are appropriate smoke detectors which are electrically connected to the fire alarms and which detectors are shown at  148 .  
         [0064]    With specific reference to FIG. 6, the details of the ceiling structure  52  for each of the modular units is shown. As previously described, the roof structure provides appropriate hanger rods or wires  56  supporting the grid system  58  for supporting the ceiling. The ceiling will include a plurality of light fixtures  160  which are supported by the grid system  58 . Power to the lighting features  160  is provided through electrical conduits extending through the side walls of each of the modular units. However, in some embodiments, as opposed to extending the power through the side walls, as disclosed in FIG. 7, polarized connections may be provided in the roofing structure similar to those previously described with respect to the side wall polarized connections.  
         [0065]    The ceiling also includes acoustic ceiling tiles  164  which are also suspended from the grid system  58 . The acoustical tiles may be of conventional construction but are non-combustible. As opposed to conventional acoustical tiles, the present invention may also incorporate sound attenuation metallic panels similar to the interior wall panels  88  which are suspended from the grid system  58 . The use of such metallic panels may be desired to provide for further fire protection and also to provide a more anechoic type interior chamber for the completed building. Where necessary, expansion joints  165  may be provided formed of an appropriate corrugated metallic or similar material which extend between the ceiling tiles  164  and the lighting features  160 . The ceiling may also be constructed of sound attenuating metallic sections that cover the entire ceiling with provision for lightning fixtures and the like to eliminate any work required to form any secondary installation of the lights at a site.  
         [0066]    With particular reference to FIG. 9, there is shown in dotted line a bathroom facility which may be utilized with the building shown in FIG. 1. The bathroom facilitate would include a toilet  170  and a sink  172 . The plumbing for the toilet and the sink  172  are disposed through the floor of the modular unit  23  and are designed to be directly connected to a source of water supply as well as to a drain pipe for conveying waste water from the facility.  
         [0067]    With particular reference to FIG. 5, the modular units  21 ,  22  and  23  of the present invention are each mounted, as previously described, on steel support beams or channels which are shown in the drawing figures as being generally c-shaped. A box beam and I-beam constructions may be also utilized. The frames are designed to be connected to concrete pads which are provided at the site of the building assembly. Appropriate steel anchor bolts are provided with each of the concrete pads which are connectable through appropriate brackets (not shown) associated with the support beams allowing the beams to be easily secured to the pads by appropriate anchoring nuts.  
         [0068]    As previously described, the modular units of the present invention are designed to be polarized in that all utility connections, electrical, plumbing, communications and the like, are properly made during the assembly of the units. As shown in FIG. 1, a primary control panel  120  is provided along the end wall of modular unit  23 . The panel includes main circuit breakers to which an outside source of electrical supply is selectively connected once the building has been assembled. Further, the control panel also includes appropriate connectors for the telephone cable and other communication equipment. Therefore, all connections made to the building are made at the exterior control panel with the exception of plumbing connections.  
         [0069]    The modular units of the present invention are specifically designed to be transportable over conventional roads and highways. In preferred embodiments, the width of each module is standardized such as to permit transport over highways without a special permit. In this respect, the modules may be 8 to 12 feet in width. The modules shown in the drawing figures would therefore be approximately 33½ feet in length. The width and length, however, may vary depending upon desired interior square footage required by the completed structure. Special permit uses would be necessary for modular construction widths of up to 14 feet and substantially longer modular unit length.  
         [0070]    To facilitate the building erection, the modular units of the present invention are designed to be maneuvered either by a conventional forklift or by crane. In this respect, appropriate openings  212  may be provided in spaced relationship with respect to one another in the floor support beams for receiving the forks of a conventional forklift. Further, steel lugs such as shown in FIG. 3 at  220  may be provided adjacent each corner of the structure having openings therein for receiving hooks or cable slings associated with a conventional crane. Therefore, manoeuverability of the modular units during assembly is facilitated for different types of equipment.  
         [0071]    With particular reference to FIG. 8, in some structures, it may be desirable to preinstall various fixtures other than the utility features within the interior of each of the modular units. As shown, it is possible to provide a plurality of work stations  230  which are securely mounted to the steel floor panels  32 A,  32 B and  32 C of the modular units  21 - 23 . Such work stations may include individual computers which are connected to an appropriate LAN system through the control panel  120   
         [0072]    In view of the steel construction of the modular units of the present invention, the completed building structures are free of structural components which promote the growth of molds, mildews and build up of moisture thus reducing the possibility of building contamination. Further, the steel construction provides a solid structure which is substantially storm resistant allowing the buildings to be erected in areas where high winds can be expected such as in areas where hurricanes may be anticipated. Further, the steel construction including both the interior and exterior walls provides a substantially fire proof structure which is extremely suitable for us as a residence, work space environment or classroom. The interior perforated steel walls, floors and ceilings together with the sound insulation also provide a living space having extremely good acoustical characteristics.  
         [0073]    Although not specifically shown in the drawing figures, each of the modular units  21 - 23  of the present invention are sufficiently rigid to allow the units to be stacked one upon another. In this respect, a complete building as shown in FIG. 1 can have a second building vertically stacked thereon by a modification of the roof structure or providing a secondary frame structure that supports and distribute the weight of the second building and by providing appropriate steel connections between the side walls of the lower unit and the side walls or floor support frame of an upper unit.  
         [0074]    The foregoing description of the preferred embodiment of the invention has been presented to illustrate the principles of the invention and not to limit the invention to the particular embodiment illustrated. It is intended that the scope of the invention be defined by all of the embodiments encompassed within the following claims and their equivalents.