You are an expert at summarizing long articles. Proceed to summarize the following text:

You are an expert at summarizing long articles. Proceed to summarize the following text: 
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims the benefit of U.S. Provisional Patent Application No. 61/209,407, filed Mar. 5, 2009, entitled “Slab Based Modular Building System,” which is incorporated herein by reference in its entirety. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not Applicable 
       INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC 
       [0003]    Not Applicable 
       FIELD OF THE INVENTION 
       [0004]    This application relates generally to building systems and, more specifically, to building systems utilizing slab-on-grade foundations. 
       BACKGROUND 
       [0005]    Shallow foundations and more particularly slab-on-grade (“slab”) foundations provide the advantages of being cheap and sturdy alternatives to other building methods used in appropriate climates. Because they are formed at the building site, however, it is often difficult or even impossible for slab foundations to meet the strict tolerances required for the use of pre-fabbed or other manufactured components. Additionally, to meet cost objectives labor costs must be kept low, mandating the use of workers with little or no training. 
         [0006]    Thus, there is a need for a slab foundation and associated system that provides precise and accurate dimensional control while reducing the need for skilled workers. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES 
         [0007]    The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention. 
           [0008]      FIG. 1  illustrates a grid system for use in the slab or floor of a building according to embodiments of the present invention. 
           [0009]      FIG. 2  illustrates a connector for the grid system of  FIG. 1 , according to embodiments of the present invention. 
           [0010]      FIG. 3  provides a detailed view of the connector illustrated in  FIG. 2 , according to embodiments of the present invention. 
           [0011]      FIG. 4  illustrates an exemplary wall panel for the grid system illustrated in  FIG. 1 , according to embodiments of the present invention. 
           [0012]      FIG. 5  illustrates an embodiment for wall to floor connection and for providing electrical and other wired materials in the wall panel illustrated in  FIG. 4 . 
           [0013]      FIG. 6  illustrates a floor or ceiling panel layout with structural support elements. 
           [0014]      FIG. 7  illustrates a floor panel and ceiling panel attached to structural support 
           [0015]      FIG. 8  illustrates an edge form for use with the grid system of  FIG. 1 . 
       
    
    
       [0016]    The present invention will be described with reference to the accompanying drawings. The drawing in which an element first appears is typically indicated by the leftmost digit(s) in the corresponding reference number. 
       DETAILED DESCRIPTION 
       [0017]    In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention, including structures, systems, and methods, may be practiced without these specific details. The description and representation herein are the common means used by those experienced or skilled in the art to most effectively convey the substance of their work to others skilled in the art. In other instances, well-known methods, procedures and components have not been described in detail to avoid unnecessarily obscuring aspects of the invention. 
         [0018]    References in the specification to “one embodiment,” “an embodiment,” “an example embodiment,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. 
       1. Overview of Grid System 
       [0019]      FIG. 1  provides an overhead view of a grid system for use in the floor of a building. Connectors  101  are spaced a regular distance from each other in a square or rectangular grid pattern. Rigid orthogonal spanners  100  are attached in-line to the connectors to provide even spacing between the connectors. A diagonal cross piece  125  is provided to square each grid. 
         [0020]    As shown in  FIG. 2 , connector  101  provides attachment points for the grid system. A connection point  207  is provided for alignment of the connector&#39;s vertical position and additional functions including but not limited to an attachment point and hold down for walls and other building elements. Connection point  209  is provided for attachment to rigid spanner  100 . Connection point  206  is provided for diagonal cross piece  125 . Alternatively the connector plate can be rotated 90 degrees, with connections to the spanners and cross pieces rotated accordingly. In the embodiment shown  FIG. 2  connector  101  is square, but as would be understood by one skilled in the art, it be rectangular or round and provide its intended purpose. 
         [0021]      FIG. 3  illustrates connector  101  with spanners  100  and cross piece  125  attached. Additionally, height adjuster  302  is shown attached to connection point  207  and resting on bearing plate  303 . Height adjuster  302  as shown in  FIG. 3  incorporates a threaded surface for mating with the threaded surface of connection point  207 . It is understood that the connection of height adjuster  302  to connection point  207  could be provided by any method that would allow for adjustment until fixed attachment is desired. As shown, height adjuster  302  is non-adjustably attached to bearing plate  303  while being adjustable at connection point  207 , but as would be understood by one skilled in the art, height adjuster  302  could be alternatively adjustable at the bearing plate  303 , or adjustable only at the bearing plate  303  while being nonadjustable at connection point  207 . In a further embodiment height adjuster  302  would rest on bearing plate  303  without being otherwise attached. 
         [0022]    In one embodiment attachment points for rebar, plumbing or heating provisions (such as hydronic heating) are provided on bearing plate  303 , on connector  101  or on height adjuster  302 . 
         [0023]    In one embodiment a threaded surface could be machined into connection point  207  without the need of a threaded nut, or an alternative to a threaded nut could be used to provide a mating surface for the various attachment means for connection point  207 . As shown spanner  100  is attached at connection point  209 , and diagonal cross piece  125  is attached at connection point  206 . 
         [0024]    Spanner  100  and diagonal cross piece  125  could be made of various materials, including plastic, metal, composite, fiberglass or any other material that would provide compatibility with concrete or concrete equivalent while providing dimensional stability for the concrete and/or the grid system. In the shown embodiment spanner  100  and cross piece  125  are rectangular in cross-section, but could alternatively be round, square, triangular or other geometric shape. 
         [0025]    Height adjuster  302  could be manufactured from metal, plastic, composite or any other material that could reliably provide for adjustment while being rigid enough to support and/or level the grid system during forming of the slab. Connector  101  could also be made of metal, composite, fiberglass or any other material that would provide a stable attachment point for other grid elements. Bearing plate  303  could be manufactured from metal, composite, fiberglass, wood or a moldable material such as concrete or plastic, including any material that can reliably provide a standoff from the surface under the floor. Temporary covers could also be provided for protection from the concrete or other material during installation. Additionally, finish covers could be manufactured from metal, composite, fiberglass, wood or a moldable material such as concrete or plastic, including any material that could provide durable flooring. 
         [0026]      FIG. 4  is a detailed view of the wall panel  412  for the grid system. Anchor bolt  413  is adapted to attach to connector plate  800 , which is a modification of connector  101  for use at the edge of the slab form. Coupler  401  receives the panel hold down bolt  415 . In the embodiment shown wall panel  412  is attached after the floor is installed. In this embodiment anchor bolt  413  is attached to coupler  401 . Wall panel  412  is modified to receive coupler  401  and anchor bolt  413  for rigid attachment to the installed floor. Wall panel  412  can be manufactured of traditional wall building materials and formed in a traditional manner. In the embodiment shown wall panel  412  is provided with cladding  417  and  419 , which could be plywood, sheetrock (gypsum board) or other lightweight material such as lime plaster or other material that could provide for light weight low cost or otherwise be suitable for prefabrication. As shown wall panel  412  presents a cavity  411 , which could be filled with insulating material or left unfilled. Additionally, the wall unit  412  could be manufactured with windows and other architectural elements built in. 
         [0027]      FIG. 5  shows an embodiment for attachment of wall panel  412  to coupler  401  and a chase  516  for providing electrical and other wired materials in the wall panel as well as plumbing. Bracket  518  is rigidly attached to wall panel  412  and provides a connection point to the floor. As would be readily understood by one skilled in the art, bracket  518  could be manufactured as part of wall panel  412  or attached to wall panel  412  at the building site. 
         [0028]    In addition to wall panels, other structural and architectural elements, including columns, stairs, and millwork pieces such as cabinets can be attached to connector plate  101  or connector plate  800 . 
         [0029]      FIG. 6  provides an embodiment of a ceiling and/or floor panel layout for the building system. Panel  620  is attached to structural support  621  with conventional methods, including but not limited to nails, screws or glue. Panel  620  is modified for intersection at edge  619 . As would be readily understood by one skilled in the art, panel  620  could be alternately a ceiling or a floor panel and could be manufactured from a variety of materials, As would be further understood by one skilled in the art, ceiling and floor panels could be made of the same or different materials depending on the application. 
         [0030]      FIG. 7  provides a detailed view of the intersection of the floor and ceiling panels to structural support elements. Floor panel  700  is attached to structural support  621 . Ceiling panel  701  is also attached to structural support  621 . 
         [0031]      FIG. 8  shows an edge form  823  for use with the grid system. In one embodiment edge form  823  is removably attached to connector  800  by coupler  824  and to bottom connector plate  801 . Coupler  824  can be a bolt and sleeve or any other attachment mechanism that would allow firm attachment and removal after the slab has cured sufficiently. Support  825  provides support for edge form  823  and may be permanently or removably attached to edge form  823  as desired. As would be understood by one skilled in the art, orthogonal spanner  100  could be the same or modified when used at the edge form. Orthogonal spanner  100  can be modified at edge conditions to allow attachment of bottom connector plate  801  to edge form  823 . In the embodiment shown attachment is accomplished with a brace  826 . As would be understood by one skilled in the art, brace  826  could be preassembled on a modified orthogonal spanner  100  or provided separately for connection to orthogonal spanner  100  in the field. 
       CONCLUSION 
       [0032]    It is to be appreciated that the Detailed Description section, and not the Summary and Abstract sections, is intended to be used to interpret the claims. The Summary and Abstract sections may set forth one or more but not all exemplary embodiments of the present invention as contemplated by the inventor(s), and thus, are not intended to limit the present invention and the appended claims in any way. 
         [0033]    The present invention has been described above with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed. 
         [0034]    The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying knowledge within the skill of the art, readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, without departing from the general concept of the present invention. Therefore, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings and guidance. 
         [0035]    The breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

Summary:
Embodiments of a slab based building system implementing a modular grid are presented herein. The square or rectangular grid may incorporate a connection point with vertical adjustment means for providing precise location of the grid elements relative to each other. An edge form is adapted to attach to the grid system. Additional building elements, such as pre-fabricated walls may be attached at the connection points.