Patent Publication Number: US-2016222651-A1

Title: Building panel, building system and method of constructing a building

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. application Ser. No. 14/252,170 filed Apr. 14, 2014, which is a continuation of U.S. application Ser. No. 13/505,952 filed May 3, 2012, which claims priority under 35 U.S.C. §371 of PCT International Application PCT/AU2011/001293, filed Oct. 11, 2011, and published under PCT Article 21(2) as WO 2012/048367 A1 on Apr. 19, 2012. PCT/AU2011/001293 claims priority from Australian application Nos. 2010904524 filed on Oct. 11, 2010, 2010904789 filed on Oct. 27, 2010, and 2011901478 filed on Apr. 20, 2011. This application is related to Australian application Nos. 2012201775 filed on Mar. 27, 2012 and 2012100346 filed on Mar. 27, 2012, which are divisional filings of PCT International Application PCT/AU2011/001293. This Application is also a continuation-in-part of PCT International Application PCT/AU2016/000036, filed Feb. 10, 2016. The entire contents of each of these prior applications/patents are hereby expressly incorporated herein by reference. 
    
    
     TECHNICAL FIELD OF THE INVENTION 
     A building panel and building system are disclosed for constructing a building. A method of constructing a building using the building panels and building system is also disclosed. 
     BACKGROUND ART 
     Third parties have proposed a building panel which comprises outer sheet members and an inner insulating panel disposed between the sheet members. However, as the thickness of such building panels increases the strength of the building panel significantly reduces to the extent that it becomes impractical to use building panels of this type for conventional building construction. 
     SUMMARY OF THE INVENTION 
     In accordance with a first aspect of the present invention, there is provided a building system comprising:
         a building panel comprising first and second outer sheet members, an inner sheet member disposed between the first and second outer sheet members, and solid insulating material disposed between the first and second outer sheet members and the inner sheet member;       

     a first track member, the first track member and the building panel being arranged such that the panel is engagable along a first side with the first track member and the first track member is connectable to the first and second outer sheet members; 
     a second track member, the second track member and the building panel being arranged such that the panel is engagable along a second side with the second track member and the second track member is connectable to the first and second outer sheet members and the inner sheet member. 
     In one embodiment, the second track member comprises a first flange that extends adjacent to and parallel with the first outer sheet member when the second track member is engaged with the panel. 
     In one embodiment, the second track member comprises a second flange that extends adjacent to and parallel with the second outer sheet member when the second track member is engaged with the panel. 
     The second track member may comprise a third flange that extends adjacent to and parallel with the inner sheet member on a side nearest the first outer sheet member when the second track member is engaged with the panel. 
     The second track member may comprise a fourth flange that extends adjacent to and parallel with the inner sheet member on a side nearest the second outer sheet member when the second track member is engaged with the panel. 
     In one embodiment, one of the first and second outer sheet members is thicker than the other of the first and second sheet members. 
     In one embodiment, at least one of the first and second outer sheet members is substantially waterproof. 
     In one embodiment, at least one of the inner and outer sheet members is formed of cement fibre board material. 
     In one arrangement, the solid insulating material comprises rigid polyurethane (PU) foam material, for example of density about 45 Kg/m 3 , or polyisocyanurate (PIR) or expanded polystyrene material (EPS). 
     In one embodiment, the second and/or first track members are formed of steel material. 
     In one embodiment the system comprises a side track member, the side track member and the building panel being arranged such that the side track member is engagable with a third side of the building panel between the first track member and the second track member. 
     In one embodiment the side track member is configured to be engagable with each of two laterally adjacent building panels. 
     In one embodiment the panel comprises first and second slots extending along each of the first and second sides of the panel to receive the first and second track members, the first slot being at an interface between the first outer sheet member and the insulating material, and the second slot being at an interface between the second outer sheet member and the insulating material. 
     In one embodiment the panel comprises a third slot extending along the second side being at an interface between the inner sheet member and the insulating material on a side of the first outer sheet member. 
     In one embodiment the panel comprises a fourth slot extending along the second side being at an interface between the inner sheet member and the insulating material on a side of the second outer sheet member. 
     In one embodiment the first and second sides are opposite each other. 
     In one embodiment the first side is a lower side and the first track member is a lower track member; and the second side is an upper side and the second track member is an upper track member. 
     In one embodiment the second track member comprises an outer second track member engagable with the panel and a connecting member connectable or engagable with the inner sheet member. The connecting member is further connectable to the outer second track member. 
     In one embodiment, the connecting member has a substantially U-shaped transverse cross sectional shape. The U-shaped member may be elongate. With this embodiment, the connecting member may comprise leg portions arranged to receive the inner sheet member there between so as to connect the connecting member to the inner sheet member and thereby connect the inner sheet member to the second track member. 
     In one embodiment, the first track member is further arranged to connect to the inner sheet member. 
     In accordance with a second aspect of the present invention, there is provided a building panel for use in a building system comprising first and second track members and building panels disposed there between, the building panel comprising: 
     a first outer sheet member; 
     a second outer sheet member; 
     an inner sheet member disposed between the first and second outer sheet members; and 
     solid insulating material disposed between the first and second outer sheet members and the inner sheet member; 
     the building panel being configured so that the building panel is receivable in a first track member and receivable in an second track member; and 
     the building panel being arranged such that the second track member is engagable with the inner sheet member and at least one of the first and second outer sheet member. 
     In accordance with a third aspect of the present invention, there is provided a building panel for use in construction of a building, the building panel comprising: 
     a first outer sheet member; 
     a second outer sheet member; 
     an inner sheet member disposed between the first and second outer sheet members; and 
     solid insulating material disposed between and bonded to the first and second outer sheet members and the inner sheet member; 
     the building panel being provided: along a first side with first and second slots each extending for a length of the first side, the first slot being at an interface between the first outer sheet member and the insulating material, and the second slot being at an interface between the second outer sheet member and the insulating material; and, along a second side with first, second, third and fourth slots each extending for a length of the second side, the first slot of the second side being at an interface between the first outer sheet member and the insulating material, the second slot of the second side being at an interface between the second outer sheet member and the insulating material, the third slot being at an interface between the inner sheet member and the insulating material on a side of the first outer sheet member, and the fourth slot being at an interface between the inner sheet member and the insulating material on a side of the second outer sheet member. 
     In one embodiment the building panel comprises, along a third side which extends between the first and second sides: first and second slots each extending for a length of the third side, the first slot of the third side being at an interface between the first outer sheet member and the insulating material, and the second slot of the third side being at an interface between the second outer sheet member and the insulating material. 
     In one embodiment the building panel comprises, along a fourth side which extends between the first and second sides opposite the third side: first and second slots each extending for a length of the fourth side, the first slot of the fourth side being at an interface between the first outer sheet member and the insulating material, and the second slot of the fourth side being at an interface between the second outer sheet member and the insulating material. 
     In one embodiment the first slots are co-joined to form a continuous first slot about the building panel. Similarly the second slots may be co-joined to form a continuous second slot about the building panel. 
     In accordance with a fourth aspect of the present invention there is provided a building panel for use in construction of a building, the building panel comprising: 
     a first outer sheet member; 
     a second outer sheet member; 
     an inner sheet member disposed between the first and second outer sheet members; and 
     solid insulating material disposed between and bonded to the first and second outer sheet members and the inner sheet member; 
     the building panel having four sides between the first and second sheet members, and being provided with continuous first and second slots extending about the four sides of the panel with the first slot being at an interface between the first outer sheet member and the insulating material, and the second slot being at an interface between the second outer sheet member and the insulating material; and, along a one of the sides third and fourth slots each of which extend for a length of the one side, the third slot being at an interface between the inner sheet member and the insulating material on a side of the first outer sheet member, and the fourth slot being at an interface between the inner sheet member and the insulating material on a side of the second outer sheet member. 
     In accordance with a fifth aspect of the present invention, there is provided a method of constructing a building panel comprising: 
     arranging a first outer sheet member, a second outer sheet member, and an inner sheet member in a mould in a substantially fixed mutually spaced apart relationship where the inner sheet member lies between the first and second outer sheet members, members; and, 
     delivering liquid reactants into the mould which react to produce a rigid polymer between, and self bonded to, the first outer, second outer and inner sheet members. 
     In one embodiment the method comprises providing the inner sheet member with a plurality of holes enabling the liquid reactants to flow between opposite side of the inner member in the mould. 
     In one embodiment arranging the sheet members comprises: placing a plurality of spacers between: the first outer sheet member and the inner sheet member; and, the inner sheet member and the second outer sheet member. 
     In one embodiment arranging the sheet members comprises stacking the sheet members, one on top the other. 
     In one embodiment each spacer is provided in the form of a tube having open opposite ends and a peripheral wall provided with one or more through holes. 
     In one embodiment the liquid reactants form polyurethane, while in another embodiment the reactants form polyisocyanurate. 
     In accordance with a sixth aspect of the present invention, there is provided a building system comprising: 
     a building panel comprising first and second outer sheet members, an inner sheet member disposed between the first and second outer sheet members, and solid insulating material disposed between the first and second outer sheet members and the inner sheet member; 
     a first track member, the first track member and the building panel being arranged such that the panel member is engagable with the first track member; 
     a second track member, the second track member and the building panel being arranged such that the panel is engagable with the second track member; and 
     a connecting member configured such that the connecting member is engagable with the inner sheet member so as to connect the inner sheet member to the second track member. 
     In one embodiment, the connecting member is separate to and engagable with the second track member, for example by providing one of the second track member and the connecting member with a recess and configuring the other of the second track member and the connecting member so that at least a portion of the second track member or the connecting member is receivable in the recess. 
     In one embodiment, the connecting member has a substantially U-shaped transverse cross sectional shape. The U-shaped member may be elongate. With this embodiment, the connecting member may comprise leg portions arranged to receive the inner sheet member there between so as to connect the connecting member to the inner sheet member and thereby connect the inner sheet member to the second track member. 
     In an alternative embodiment, the connecting member is integral with the second track member. 
     In one embodiment, the system comprises a further connecting member configured such that the further connecting member is engagable with the inner sheet member so as to connect the inner sheet member to the first track member. The further connecting member may be separate to or integral with the first track member. 
     In a seventh aspect of the invention there is provided a method of constructing a building comprising: 
     providing a plurality of building systems according to the first aspect; 
     placing a layer of a water proof material on a slab of the building; 
     fixing one or more of the panel assemblies to the slab over the waterproof layer. 
     In one embodiment the method comprises: 
     forming a corner of the building by standing two of the panels upright and abutting the panels together in respective intersecting planes to form a first angle between the two panels;
         providing a corner joint member having a joint corner defining a joint angle, the corner joint member configured to engage one of the first or second sides of the two panels forming the building corner, the corner joint member further arranged to allow distortion of the corner joint member to vary the joint angle to conform with the first angle;       

     engaging the corner joint member with each of the two panels; and, coupling the corner joint member with each of the two panels. 
     In one embodiment the method comprises: 
     arranging a first plurality of the panels to construct walls to form a lower story of a building; 
     constructing formwork to lie substantially flush with an uppermost surface of the lower story and extending partially across the first panels of the lower story; 
     pouring concrete onto the formwork to form upon setting, a suspended slab wherein a peripheral edge of the slab is supported on the first panels; and, 
     coupling a second plurality of further panels to the suspended slab to construct a wall of a second story. 
     In one embodiment the method comprises a rebating the second plurality of panels and arranging the rebated second panels on top of the first panels of the lower story with the rebates seating on or otherwise receiving the peripheral edge of the suspended concrete slab. 
     An eighth aspect of the invention provides a method of constructing a building comprising: 
     a plurality panel according to the third or fourth aspect; 
     connecting a first track member to a slab of the building; 
     engaging one or more of the panels in the first track; 
     connecting one or more panels to the first track with a plurality of mechanical fasteners that extend through one or both of the first and second outer sheet members; 
     engaging a second track with the second side of the one or more panels; and, 
     connecting the one or more panels to the second track with a plurality of mechanical fasteners that extend through the one or both of: the first outer sheet member and the inner sheet member; and, the second outer sheet member and the inner sheet member. 
     In one embodiment connecting the second track comprises connecting a first flange of the second track to the first sheet member with a first mechanical fastener, connecting a second flange of the second track to the second sheet member with a second mechanical fastener, connecting third flange of the second track to the inner sheet member with the first mechanical fastener, and connecting a fourth flange of the second track to the inner sheet member with the second mechanical fastener. 
     According to a ninth aspect of the invention there is provided a panel for use in a building system comprising a first track member for receiving a first side of the panel, the panel comprising first and second outer sheet members, an inner sheet member disposed between the first and second outer sheet members, a first frame structure disposed between the first outer sheet member and the inner sheet member and a second frame structure disposed between the second outer sheet member and the inner sheet member, and core material disposed between the first and second outer sheet members and the inner sheet member; wherein 
     each of the first and second frame structures comprises a plurality of bodies arranged in a spaced apart relationship with respect to each other, and a second track member, the bodies of each frame structure are joined together at a second side, opposite to the first side, by the second track member defining a first track assembly. 
     In some embodiments, the panel comprises a plurality of spacers arranged in such a manner that a spacer is disposed between the first outer sheet member and the first frame structure, a spacer is disposed between the first frame structure and the inner sheet member, a spacer is disposed between the inner sheet member and the second frame structure, and a spacer is disposed between the second frame structure and the second outer sheet member. 
     In some embodiments, there are a first set of the plurality of spacers located at a first lateral side of the panel and a second set of the plurality of spacers located at a second lateral side of the panel. 
     In some embodiments, the second track member of each frame structure comprises a first flange that extends adjacent to and parallel with the respective outer sheet member and a second flange that extends adjacent to and parallel with the inner sheet member. 
     In some embodiments, the core material comprises edges adapted to be sandwiched between the first and second flanges of the second track member. 
     In some embodiments, each of the bodies comprises a first flange that extends adjacent to and parallel with the respective outer sheet member and a second flange that extends adjacent to and parallel with the inner sheet member. 
     In some embodiments, the core material comprises edges sandwiched between the first and second flanges of the bodies. 
     In some embodiments, the panel comprises first and second slots extending along the first side of the panel to receive flanges of the first track member, the first slot being at an interface between the first outer sheet member and the core material, and the second slot being at an interface between the second outer sheet member and the core material. 
     In some embodiments, the panel comprises one first third slot extending along the first side, the first third slot being at an interface between the inner sheet member and the core material on a side of the first outer sheet member and a second third slot extending along the first side, the second third slot being at an interface between the inner sheet member and the core material on a side of the second outer sheet member. 
     In some embodiments, the first side comprises a lower side and the first track member comprises a lower track member, the second side comprises an upper side and the second track members comprises upper track members, and the first track assembly comprises a top track assembly. 
     In some embodiments, the top track assembly comprises the second track members insulated with respect to each other through the inner sheet member. 
     In some embodiments, each of the first and second frame structures further comprises a third track member joining the bodies of each of the frame structures at the first side defining a lower track assembly. 
     In some embodiments, the lower track assembly comprises the third track members insulated with respect to each other through the inner sheet member. 
     In some embodiments, at least one of the inner and outer sheet members is formed of cement fibre board material. 
     In some embodiments, the core material comprises rigid polyurethane (PU) foam material, for example of density about 45 Kg/m 3 , or polyisocyanurate (PIR) or expanded polystyrene material (EPS). 
     In some embodiments, the first track members is formed of steel material. 
     According to a tenth aspect of the invention there is provided a building system comprising: 
     a panel comprising first and second outer sheet members, an inner sheet member disposed between the first and second outer sheet members, a first frame structure disposed between the first outer sheet member and the inner sheet member and a second frame structure disposed between the second outer sheet member and the inner sheet member, and core material disposed between the first and second outer sheet members and the inner sheet member; 
     a first track member, the first track member and the building panel being arranged such that the panel is engagable along a first side of the panel with the first track member and the first track member connectable to at least any one of the first and second outer sheet members; wherein 
     each of the first and second frame structures comprises a plurality of bodies arranged in a spaced apart relationship with respect to each other, and a second track member, the bodies of each frame structure are joined together at a second side by the second track member defining a first track assembly. 
     In some embodiments, the panel comprises a plurality of spacers arranged in such a manner that a spacer is disposed between the first outer sheet member and the first frame structure, a spacer is disposed between first frame structure and the inner sheet member, a spacer is disposed between the inner sheet member and the second frame structure, a spacer is disposed between the second frame structure and the second outer sheet member. 
     In some embodiments, there are a first set of the plurality of spacers located at a first lateral side of the panel and a second set of the plurality of spacers located at a second lateral side of the panel. 
     In some embodiments, each of the second track members comprises a first flange that extends adjacent to and parallel with the respective outer sheet member and a second flange that extends adjacent to and parallel with the inner sheet member. 
     In some embodiments, each of the bodies comprises a first flange that extends adjacent to and parallel with the respective outer sheet member and a second flange that extends adjacent to and parallel with the inner sheet member. 
     In some embodiments, the panel comprises first and second slots extending along the first side of the panel to receive the first track member, the first slot being at an interface between the first outer sheet member and the core material, and the second slot being at an interface between the second outer sheet member and the core material. 
     In some embodiments, the first side comprises a lower side and the first track member comprises a lower track member, the second side comprises an upper side and the second track members comprises an upper track members, and the first track assembly comprises a top track assembly. 
     In some embodiments, each of the first and second frame structures further comprises a third track member joining the bodies of each of the frame structures at the first side. 
     In some embodiments, the panel comprises a plurality of third slots extending along the first side, a first third slot being at an interface between the inner sheet member and the core material on a side of the first outer sheet member and one second third slot extending along the first side, the second third slot being at an interface between the inner sheet member and the core material on a side of the second outer sheet member. 
     In some embodiments, the first track member comprises outer flanges adapted to be received by first and second slots, and inner flanges adapted to be received by the third slots. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: 
         FIG. 1  is a diagrammatic representation of a building system according to a first embodiment of the present invention; 
         FIG. 2  is a section view of a panel incorporated in the system shown in  FIG. 1 ; 
         FIG. 3  is a diagrammatic perspective view of an upper track member of the building system shown in  FIG. 1 ; 
         FIG. 4  is schematic representation of a use of the building system to construct a building; 
         FIG. 5  is a longitudinal cross section view of a building system and panel; 
         FIG. 6  is a schematic representation of a second embodiment of a building system and panel in accordance with the present invention; 
         FIG. 7  is a transverse section view of the building system shown in  FIG. 6 ; 
         FIG. 8  is a schematic representation of a side connector or track for the building system shown in  FIGS. 6 and 7 ; 
         FIG. 9  is an end view of a side connector incorporated in the building system shown in  FIG. 6 ; 
         FIG. 10  is a schematic representation of a third embodiment of a building panel and system in accordance with the present invention; 
         FIG. 11  is a schematic representation from the top of a corner connector utilised in embodiments of the building system; 
         FIG. 12  is a schematic representation from the bottom of the corner connector shown in  FIG. 11 ; 
         FIG. 13  is a cross section view of a portion of a two story building constructed utilising embodiments of the building system and panels; 
         FIG. 14  is a schematic representation of a further embodiment of a building panel in accordance with the present invention; 
         FIG. 15 a    is a representation of a brace incorporated in a method of constructing a building in accordance with the present invention; 
         FIGS. 15 b -15 e    are representations of specific components where parts of the brace are shown in  FIG. 15   a;    
         FIG. 16  is a representation of an upper track which may be utilised in a further embodiment of the building panel and building system; 
         FIG. 17  illustrates a variation in a method of constructing a building in accordance with the present invention; 
         FIG. 18  is a diagrammatic representation of a building system according to a second embodiment of the present invention; 
         FIG. 19  is a top view of the building system shown in  FIG. 18  and a cross-sectional view of the building system along the plane C shown in  FIG. 18 ; 
         FIG. 20  is a side view of the building system shown in  FIG. 18  and a cross-sectional view of the building system along the plane D shown in  FIG. 18 ; 
         FIG. 21  is the detail F shown in  FIG. 19  of an upper portion of the building system show in  FIG. 18 ; 
         FIG. 22  is the detail G shown in  FIG. 19  of a lower portion of the building system shown in  FIG. 18 ; 
         FIG. 23  is the detail E shown in  FIG. 20  of a side portion of the building system shown in  FIG. 18 ; 
         FIG. 24  is a diagrammatic representation of the building system shown in  FIG. 18  in exploded condition; 
         FIG. 25  is a perspective view of one of the frame structures comprising an upper track member supported on side bodies; and 
         FIG. 26  is a perspective view of an alternative arrangement of a lower track member. 
     
    
    
     DETAILED DESCRIPTION FOR CARRYING OUT THE INVENTION 
     Referring to the drawings and in particular  FIG. 1 , there is shown a building system  10  for use in constructing walls of a building. 
     The building system  10  comprises building panels  12  formed of sheet members and core material, first track members  14 , and second track members  16 . In this example the first track members  14  are lower track members in that they extend along a first or lower side of the panels  12  while the second track members  16  are upper track members in that they extend along a second or upper side of the panels  12 . For ease of reference in this description the first track members will be referred to as lower track members  14  and the second track members will be referred to as the upper track members  16 . 
     In this example, multiple building panels  12  and multiple upper and lower track members  14 ,  16  are provided with the multiple lower and upper track members  14 ,  16  disposed along a path of a desired wall in endwise relationship and multiple building panels disposed in endwise relationship between the lower and upper track members  14 ,  16  so as to define a wall. 
     Each building panel  12  comprises a first outer sheet member  20  intended during use to face inwardly of a building wall, a second outer sheet member  22  intended during use to face outwardly of a building wall, and an inner sheet member  24  disposed between the first and second outer sheet members  20 ,  22 . 
     Examples of the materials from which sheets  20 ,  22  and  24  may be made include, but are not limited to, fibre cement board, wood sheets for example pine sheets; plaster board, Colorbond, MGL (magnesium oxide) board and composite materials. Further, in various embodiments, different materials may be used for respective sheets  20 ,  22  and  24  in any particular panel  12 . 
     Also in the present example, since the second outer sheet member  22  is intended to face outwardly of a building and may as a consequence become exposed to ambient moisture, the second outer sheet member  22  is configured so as to be waterproof. In addition, in this example, the second outer sheet member  22  is thicker than the first outer sheet member  20  and the inner sheet member  24 . In one embodiment, the first outer sheet member  20  and the inner sheet member  24  are approximately 4.5 mm thick and the second outer sheet member  22  is 6 mm thick. 
     Each building panel  12  also comprises multiple cores, in this example first and second cores  26 ,  28 , each of which is disposed between the inner sheet member  24  and one of the outer sheet members  20 ,  22 . Thus panel  12  can be considered to be a two or dual core panel. Each of the first and second cores  26 ,  28  is formed of solid core material, such as a rigid polymer and more particularly a rigid thermosetting polymer such as in this example rigid polyurethane (PU) foam material. In one example the PU may have a density of approximately 45 Kg/m 3 . Such material has good fire retardant properties, including a high flash point of the order of 300° C. However, it will be understood that other core material is envisaged such as polyisocyanurate (PIR) or expanded polystyrene material (EPS) may be used. 
     The sheet members  20 ,  22 ,  24  may be fixed to the cores  26 ,  28  in any suitable way, for example by adhesives or thermal bonding. Indeed thermal bonding may occur as self bonding arising from the inherent properties of the rigid core material. 
     A first slot  30   a  and a second slot  30   b  extend along a first or lower side  31  of the panel. The first slot  30   a  is at an interface between the first outer sheet member  20  and the core material  26 . The second slot  32   a  is at an interface between the second outer sheet member  22  and the core  28 . The slots  30   a  and  32   a  create internal shoulders  33  in the cores  26 ,  28 . 
     A first slot  30   b , second slot  32   b , third slot  34   b  and fourth slots  36   b  each extend along and for the length of a second side or upper side  37  of the panel  12 . The second side  37  is opposite the first side. The first slot  30   b  is at an interface between the first outer sheet member  20  and the core  26 , the second slot  32   b  is at an interface between the second outer sheet member  22  and the core  28 , the third slot  34   b  is at an interface between the inner sheet member  24  and the  26  on a side of the first outer sheet member  20 , and the fourth slot  36   b  is at an interface between the inner sheet member  24  and the core  28  on the side of the second outer sheet member  22 . 
     The slots  30   b ,  32   b ,  34   b  and  36   b  form respective internal shoulder  39  near the second side  37  of panel  12 . 
     In the present example, the thickness of the building panel  12  is approximately 90.8 mm, although any suitable building panel thickness is envisaged, such as any thickness in the range 70 mm to 250 mm. 
     Each lower track member  14  includes a base plate  40  and two substantially parallel elongate ribs or flanges  42  defining a lower channel  44  there between. 
     The lower channel  44  and the slots  30   a  and  32   a  are configured such that the building panel  12  is engagable with the first or lower track member  14  by receiving the flanges  42  the slots  30   a  and  32   a . Moreover as will be explained in greater detail later, the lower track  14  is connected to the panel  12  by mechanical fasteners that pass through the first and second outer sheets  20 ,  22  and respective adjacent flanges  42 . 
     With reference to  FIGS. 1 and 3  each second or upper track member  16  includes a base plate  50  and two substantially parallel outer first and second elongate ribs or flanges  52   a  and  52   b  (referred to in general as “flanges  52 ”) defining an upper channel  54  there between. Upper track member  16  also includes a third flange  56   a  and a fourth flange  56   b  (referred to in general as “flanges  56 ”). 
     The flanges  56  are spaced apart by distance marginally greater than the thickness of inner sheet  24  so as to seat in slots  34   b  and  36   b  and closely fit over a second or upper portion inner sheet  24  when the upper track  16  is engaged with panel  12 . More particularly the flanges  56  lie adjacent to and parallel with opposite sides of the inner sheet  24 . Of course at this time the flanges  52  seat in slots  30   b  and  32   b  and thus lie adjacent to and parallel with first and second outer sheets  20  and  22  respectively. 
     As will be explained in greater detail later, the upper track  16  is connected to the panel  12  by mechanical fasteners that pass through the first and second outer sheets  20 , inner sheet  22  and flanges  52  and  56 . This mechanically connects the first and second outer sheets  20 ,  22  to the inner sheet  24  outer and is believed to provide enhanced panel compression strength as well as panel integrity. 
     The upper and lower tracks  14 ,  16  may be formed of steel material, although it will be understood that other suitably strong materials are envisaged. It is envisaged that each of the tracks  14  and  16  is formed as respective integral stock (for example respective continuous extrusions) and cut to a required length. 
     With reference to  FIGS. 4 and 5  in order to construct a wall W, a user first fixes a lower track member  14  to a foundation of a proposed building, such as a concrete slab  62 , in any suitable way. One or more building panels  12  are then engaged with the lower track members  14  by receiving the flanges  42  of the lower track members  14  in the slots  30   a ,  30   b  in the first or lower side  31  of the panels  12 . 
     The building panels  12  are fixed to the lower track members  14  in any suitable way, for example mechanical fasteners such as screws  64 . The screws  64  are driven through the first and second outer sheets  20 ,  22  into and through the respective adjacent flanges  42  and cores  26 ,  28 . The screws may be chosen to be of a length that does not penetrate to the inner sheet  24 . Although they may also be of sufficient length to extend through the inner sheet  24 . 
     An upper track  16  is then engaged with the building panels  12  in the lower track  14  by receiving the flanges  52  and  56  into the slots  30   b ,  32   b ; and slots  34   b  and  36   b , respectively. The building panels  12  are then fixed to the upper track members  16  in any suitable way, for example mechanical fasteners such as screws  66 . The screws  66  are driven through the first and second outer sheets  20 ,  22  into and through the respective adjacent flanges  42  and cores  26 ,  28 . The screws are chosen to be of a length that does also penetrate at least the closest of the flanges  56  and the inner sheet  24 . However the screws  66  may be of a length that extends through either of the first and second outer sheets and the inner sheet  24 . For example in  FIG. 5  one screw  66  is shown passing through first sheet  20 , adjacent flange  52   a , core  26 , flange  56   a , inner sheet  24  and opposite adjacent flange  56   b . Another screw  66  is shown passing through second sheet  22 , adjacent flange  52   b , core  28 , flange  56   b , inner sheet  24  and opposite adjacent flange  56   a.    
     Roof trusses and frames may then be coupled to the upper track  16  to further the construction of a building. 
       FIGS. 6-9  illustrate a second embodiment of a building system  10   a  and corresponding building panels  12   a  in accordance with the second embodiment of the invention. In the following description features which correspond either in structure or function to those of the first embodiment are denoted with the same reference. The building system  10   a  and the building panels  12   a  are substantially the same as building system  10  and panels  12 . The substantive differences between the system  10   a  and panels  12   a  and the system  10  and panels  12 , in brief, comprise: the inclusion of side track members  70 ; the provision of first and second slots  30   c ,  32   c  along a third side  72  of panel  12   a , and the provision of first and second slots  30   d ,  32   d  along each of an opposite fourth side  74  of panel  12   a . The slots  30   c ,  32   c ; and  30   d ,  32   d  accommodate the side track members  70 . 
     The side track members  70  facilitate lateral or side-to-side coupling between adjacent panels  12   a . The side track members  70  are in essence of the same or similar form and construction as lower track members  14 . 
     Side track members  70  are in the form of u-shaped steel extrusions having a central base plate  76  and flanges  78  extending in the same direction from opposite longitudinal sides of the base plate  76 . However, as shown in  FIGS. 7 and 8 , a portion of the flanges  78  near each end of side track member  70  is cut away in order to accommodate the flanges of upper track member  16  and lower track member  14 . 
     The first slots  30   c  and  30   d  are formed along the length of each of the sides  72  and  74  and at an interface between first outer sheet member  20  and core layer  26 . The second slots  32   c  and  32   d  are formed along the length of each of the sides  72  and  74  and at an interface between second outer sheet member  22  and core layer  28 . 
     More particularly the first slots  30   a ,  30   b ,  30   c  and  30   d  are co-joined to form a continuous first slot  30  about the panel  12   a . Likewise the second slots  32   a ,  32   b ,  32   c  and  32   d  are co-joined to form a continuous second slot  32  about the panel  12   a.    
     In order to enable lateral coupling of adjacent panels  12   a  together along their longitudinal sides, pairs of side track members  70  may be connected together back-to-back to form lateral connectors  80  as depicted in  FIGS. 4 and 9 . In  FIG. 9  the respective side track members  70  which form the lateral connector  80  are depicted as being slightly spaced apart however this is for ease of representation only. In practice, the base plates  76  of side track members  70  would be in contact with each other and attached together by way of a plurality of mechanical fasteners or spot welding. Each side track member  70  is attached to its corresponding panel  12   a  by a plurality of screws which pass through first and second outer sheet members  20  and  22  in a similar manner to that described and depicted in relation to the upper and lower track members  14  and  16 . 
     In order to manufacture a panel  12  or  12   a , the sheet members  20 ,  22  and  24  are arranged within a mould in a substantially fixed mutually spaced apart relationship, and liquid reactants for example as required to form polyurethane or polyisocyanurate are delivered or injected into the mould. The reactants when reacting expand and fill the space or void between the sheet members and, due to their inherent properties, self bond to the sheet members. In order to hold the sheet members in the fixed spaced apart relationship, a plurality of spacers  82  (shown in  FIG. 7 ) are used between respective adjacent sheets. In this particular example, the spacers  82  are in the form of PVC tubes which are open at each opposite axial end and have a circumferential wall  84  provided with a plurality of through holes  86 . During the manufacturing process, the sheet members are arranged in an overlying juxtaposition and spaced apart by the spacers  82 . For example, first outer sheet member  20  may be first placed in a mould, then a plurality of spacers  82  placed on the first outer sheet member  20 ; inner sheet  24  is then placed on top of the spacers  82 ; a further plurality of spacers  82  is supported on inner sheet  24 ; and, finally second outer sheet  22  is placed on the spacers. The mould is then closed preventing motion of the sheet members away from each other and the liquid reactants delivered into the mould. To assist further in the manufacturing process a plurality of through holes may be formed in the inner sheet  24  prior to placing in the mould. The holes enable liquid reactants and the forming rigid polymer to pass through the holes to equalise pressure on opposite sides of sheet  24  preventing warping or fracturing that may otherwise arise due to high pressures generated in the manufacturing process. 
     The slots formed in the panels  12 ,  12   a  to accommodate the track members may be formed by use of cutting instruments which cut the slots to the desired depth about the sides of the panel  12 ,  12   a.    
     The resulting panel  12 ,  12   a  forms a structural or load bearing panel which may be used, for example, in place of bricks or concrete panels in the construction of buildings. 
     A method of constructing a two story building  100  utilising a plurality embodiments of panel systems and in panels will now be described with reference to  FIGS. 10-15   e . Building  100  comprises concrete slab or pad  62  which in one example may have a thickness of 70 mm to 150 mm. The slab  62  is laid on foundations (not shown). An outer wall of building  100  is constructed from modified panels  12   b  (see in particular  FIG. 10 ). The modified panels  12   b  differ from the panels  12   a  described hereinabove by forming an outer sheet  22  with an extended edge  102  that extends beyond the corresponding edge of outer sheet  20  so that when panel  12   b  is fixed to the slab  62 , the edge  102  lies below upper surface  104  of slab  62  to form a recess or pocket  106  between a vertical side face  108  of slab  69  and the sheet  22 . Panels  12   a  are used to construct internal walls of the building  100 . 
     In order to provide waterproofing to the building  100  and in particular between the slab  62  and panels  12   b , a layer of waterproof material  110  is placed on slab  62  beneath the panels  12   b  which form the outer peripheral wall of building  100 . The waterproof layer  110  is configured and arranged so that the panels  12   b  are fixed to the slab over the layer  110  as shown most clearly in  FIG. 10 . The waterproof layer  110  may be in the form, for example, of building paper. Thus during construction of the building  100 , the building paper  110  is laid on the slab  62  prior to attachment of the lower or bottom track  14 . Track  14  is then fixed to the slab  62  by use of appropriate fasteners such as, for example, chemical anchors  112 . Building panels  12   b  are then seated in the bottom track  14  and fixed thereto in the manner described hereinabove. 
     The waterproof layer  110  is configured and arranged in this embodiment so as to extend beyond the slab  62  and turn or curve down into the pocket  106  abutting an inside surface  114  of sheet  22 . 
     As shown in  FIG. 10  waterproofing of building  100  is enhanced by the provision of sealant  116  between lower tracks  14  and slab  62 . In this embodiment, sealant  116  is provided as two beads  118  and  120  of settable sealant material. First bead is  118  provided between the waterproof layer  110  and slab  62 . The second bead  140  of settable sealant material is provided between the waterproof layer  110  and the lower track  14 . In this particular embodiment, the sealant beads  118  and  120  are laterally offset from each other. 
     It would be appreciated that any water entering the pocket  106  is stopped from passing between panels  12   a  and slab  62  by way of the waterproof layer  110  and the sealant  116  and moreover sealant beads  118  and  120 . Further, any moisture in slab  69  is isolated from bottom track  14  by way of the waterproof layer  110 . 
     When constructing a building  100 , a corner  122  (see  FIG. 11 ) is formed by standing two panels  12   bx  and  12   by  upright and abutting the panels together in respective intersecting planes. In this particular example, the intersecting planes are at first angle θ 1  which is intended to be a right angle. In order to provide stability and facilitate the coupling of the panels  12   bx  and  12   by  at the corner  122 , a corner joint member  124  is provided. The corner joint member  124  is configured to form a corner  126  having a corner angle θ 2 . Corner joint member  124  engages both the panels  12   bx  and  12   by  about the corner  122 . Moreover, corner joint member  124  is configured to allow it to distort or flex in order to vary the joint corner angle θ 2  to conform or match with the first angel  81 . This in effect provides a degree of give or compliance allowing the coupling of the joint member  124  to the underlying panels  12   bx  and  12   by.    
     Corner joint member  124  comprises a base plate  128  from which depends outer longitudinal flanges  130   a  and  130   b  (see in particular  FIG. 12 ). As is apparent from  FIG. 12 , a discontinuity  131   a  is formed in the flange  130   a  about the corner  126  and a discontinuity  131   b  is formed in the flange  130   b  about corner  126 . These discontinuities enable flexing of the corner joint member  124  in the plane of plate  128  to allow the member to seat in the panels  12   bx  and  12   by.    
     The corner joint member  124  is also provided with intermediate pairs of spaced apart flanges  132   a  and  132   b  that are arranged and configured to seat in slots  34   b  and  36   b  on opposite sides of inner sheet  24  in the corner panels  12   bx  and  12   by.    
     As may be apparent from the above description the corner joint member  124  in effect comprises two lengths of upper cap or track  16  with ends joined to form corner angle θ 2  but with adjacent portions of the walls or flanges  52   a  and  52   b  on opposite sides of corner  126  being removed so as to form discontinuities or spaces  131   a  and  131   b.    
     Corner joint panel  124  is coupled to the corner panels  12   bx  and  12   by  in the same manner as described hereinabove in relation to the upper track  16 . 
     Due to their construction, the panels  12 ,  12   a , and  12   b  (referred to in general as “panels  12 ”) have substantial compressive and load bearing strength. For example, panels  12  of a thickness of between 210 mm and 250 mm and have been tested to withstand a compressive load of 25 tons. This enables multi-story buildings with suspended concrete floors to be constructed from embodiments of panels  12 . 
       FIG. 13  illustrates a portion of the two story building  100  constructed from a plurality of panels  12 . Building  100  has a lower story  142  having a peripheral (or outer) lower story wall  144  made from a plurality of panels  12   b . The panels  12   b  are coupled to an underlying slab  62 . Slab  62  may be a ground level slab, or indeed a slab of a higher story. A second story  146  of building  100  has an upper story peripheral wall  148  comprising a plurality of panels  12   c  which are supported on underlying panels  12   b . The panels  12   c  differ from the panels  12   a  (shown in  FIGS. 6 and 7 ) by the provision of a longitudinal rebate  150  along bottom edge of panel  12   c  from the sheet  20  to a depth to expose the inner sheet  24 . Thus a portion of the sheet  20  and core  26  are removed to expose inner sheet  24 . When the upper story wall  148  is placed on top of the lower story wall  142 , the rebate  150  forms a continuous ledge or seat for supporting a suspended concrete slab  152 . 
     Building system  10   c  corresponding to the panel  12   c  further differs from the building system of panel  12   a  by the replacement of bottom cap or track  14  with two right angle tracks  14   a  and  14   b . The tracks  14   a  and  14   b  may be considered to be a track  14  which is cut longitudinally in a manner which removes sufficient material so that each track  14   a ,  14   b  is able to seat between a respective outer sheet  20 ,  22  and inner sheet  24  (as shown in  FIG. 13 ). 
     In one method of constructing the multi-story building  100 , after the lower story peripheral wall  144  and indeed other walls of the lower story  142  have been secured to the slab  62 , formwork may be erected to enable the pouring of slab  152 . The formwork would include horizontal panels which have an upper surface at a level substantially flush with a lower level of the rebate  150  when the upper story walls  146  are placed on lower story walls  142 . In this instance, this level corresponds with the level of the top of peripheral wall  144 . Next, side panels of the formwork are attached at locations which correspond with the position of inner sheet  24  of upper peripheral wall  148  when seated on lower peripheral wall  144 . The depth of the formwork corresponds with the height or depth of rebate  150 . Concrete is now poured onto the formwork and allowed to set to form the suspended slab  152 . Once the slab  152  has set, the formwork is removed, and the panels  12   c  are fixed to the underlying slab  152  and panels  12   b  to form the peripheral wall  108 . This is achieved by fastening the bottom tracks  14   b  to the upper tracks  16  of underlying wall  144 , and attaching the bottom tracks  14   a  to the slab  152  using chemical anchors or chemical fasteners. Thereafter, the panels  12   c  can be seated in the tracks  14   a  and  14   b  and fastened thereto by way of conventional screws or fasteners screwed into the outer sheets  20  and  22  into corresponding bottom tracks  14   a  and  14   b  respectively. 
     In an alternate method of construction of multi-story building  100 , the panels  12   c  may be erected on underlying panels  12   b  with bottom tracks  14   b  fastened to the upper track  16  in the manner described hereinabove and with the additional use of stays to support the upper panels  12   c  during pouring of the suspended slab  152 . However in this method, the bottom track  14   a  may also be provided with wire ties or bolts that extend from a bottom plate of the tracks  14   a  into rebate  150 . Formwork is now erected in the building  100  but in this instance, the formwork only requires the laying of horizontal supports up to the lower level of rebate  150 . The rebate  150  in effect forms part of the formwork to receive the poured concrete. When the concrete is poured, it flows into the rebate  150  and envelops the wire ties or bolts extending from the bottom tracks  14   a.    
     When outer peripheral wall  148  of upper story  146  has been erected, upper tracks  16  and corner joint members  124  are seated in the slots at the upper end of the panels  12   a ′ and attached thereto in the manner described hereinbefore. 
     A roof truss (not shown) can be fitted directly to the top track in the panels  12   c  to support a roof covering  154 . Internal walls of the building  100  can be constructed from panels  12  and/or  12   a.    
     In order to support the panels during the construction of a building and prior to fitting of the upper track  16 , braces  160  as shown in  FIGS. 15 a -15 e    may be used. Brace  160  comprises a telescopically arranged outer pipe  162  and inner pipe  164 . A plurality of holes  166  is formed in the outer pipe  162 . One or more transverse holes (not shown) are also formed in inner pipe  164  that can register with at least one of the holes  166 . Pipes  162  and  164  can be temporarily locked together by insertion of a locking pin  168  into mutually registering holes in the pipes  162  and  164 . Locking pin  168  is attached to outer pipe  166  via a chain or tether  170 . A plate  172  is attached to an end of inner pipe  164  distant the pipe  162  via a bracket  174  and pivot bolt  176 . The pivot bolt  176  passes through the bracket  174  and inner pipe  164 . Bolt  174  is fastened in a manner to enable the bracket  174  and thus the plate  172  to pivot about an axis of the bolt  176 . A pair of holes  178  is formed in plate  172  to receive fasteners such as screws to attach plate  172  to a panel  12 . 
     Brace  160  also comprises a turnbuckle  180  threadingly connected to: a stud  182  which in turn is screwed into the outer pipe  162 ; and, an eye stud  184  which in turn is connected to a base plate  186 . A nut  188  threadingly engages the stud  182  and locks the stud  182  to the outer pipe  162 . Plate  186  is attached to the eye stud  184  via a bracket  189  and pivot bolt  190  in a manner similar to the connection of plate  172 . Thus the plate  186  is able to pivot about a longitudinal axis of bolt  190 . A pair of holes  192  is formed in plate  186  to receive mechanical fasteners and to enable attachment to a support surface such as a slab  62  or suspended slab  162 . Turning of the turnbuckle  180  enables adjustment in the length of brace  160 . 
     The braces  160  are used to assist in supporting panels  12  during the construction of a building  100 . The adjustability in length of braces  160  enable the panels  12  to be plumbed prior to attachment of the upper track  16 . When the braces  160  are in use, coarse adjustment in the length of brace  160  is performed by appropriate telescoping or retracting the pipes  162  and  164  and temporarily locking them together by use of pin  168 . Plate  186  may then be temporarily attached to a support surface such as slab  62  or suspended slab  152  by use of mechanical fasteners driven through the holes  192 . Thereafter, plate  172  is pivoted to be in face-to-face contact with adjacent outer sheet  20  or  22  of a panel  12 . Screws are then driven through holes  178  to temporarily attach the plate  172  to the panel  12 . By using appropriate measurement apparatus such as plumb line, spirit line or a laser line, turnbuckle  180  is turned to adjust the overall length of brace  160  to ensure that the corresponding panel  12  is plumb, i.e. as close to vertical as practically possible. Each panel  12  of a corresponding wall is adjusted in a similar manner. Thereafter, upper track  16  is applied over two or more side-by-side adjacent panels  12  and subsequently fixed to the panels. Braces  160  may then be removed. 
     The panels  12  may also be modified to create decorative finishes internal of a building. For example, one or more panels  12  may be modified to produce a decorative panel incorporating a corporate logo. This may be achieved as follows. First outer sheet  20  or portion thereof may be removed from the panel  12  exposing a surface of the underlying core  26 . The core  26  can be subsequently engraved or cut for example with a CNC machine to produce the desired visual effect. This portion of the exposed core  26  may then be finished with surface finishing such as paint, epoxy resins or even layers of composite material. Thus, when a building is constructed one or more of the panels  12  may be formed in this manner to produce a desired internal visual effect. 
     It will be appreciated that the building system  10  enables relatively thick building panels  12  to be used without compromising strength, and in particular to provide building walls which have a thickness generally corresponding to the thickness of walls of conventional buildings, such as double brick wall type buildings, without compromising strength. 
     It will be understood that since relatively thick walls are possible without compromising strength, it is possible to construct a building with exceptional energy ratings, in particular thermal insulation ratings, because significantly more core material is included in the building panels  12  than in relatively thin building panels known hitherto. 
     It will also be understood that since relatively thick building panels of similar thickness to conventional building walls can be used in the building process, it becomes possible to use other conventional building components such as conventional windows without compromising aesthetic appearance. 
       FIG. 17  illustrates a further building system  10   d  and associated panel  12   d  for constructing a multi-story building  100   d . The panel  12   d  is similar to the panel  12   c  shown in  FIG. 14  but orientated so that the recess  150  is at an upper end of the panel  12   d  rather than the lower end. Consequently, the recess  150  itself forms a part of the form work for a poured slab  152 . In the building system  10   d , two C channels  16   d  and one L channel  17  are incorporated. The panel  12   d  is provided with first, second, third and fourth slots  30   b ,  32   b ,  34   b  and  36   b  in a manner similar to that shown for the panel  12  in  FIG. 1 . One of the C channels  16   d  seat in slots  30   b  and  34   b ; and the other seats in slots  36   b  and  32   b . The L channel  17  seats in the recess  150  and abuts the inner panel  24  and a base of the C channel  16   d . Mechanical fasteners connect the L channel  17  to both of the C channels  16   d . Thus when constructing a building  100   d  using the building system  10   d  and panel  12   d , once the building system  10   d  has been attached to an underlying slab  62 , form work is then provided as a horizontal support up to the level of the recess  150 . Concrete is then poured up to the top of inner sheet  24 . The recess  150  acts as part of the form work and receives a peripheral edge of the slab  152 . 
     Now that embodiments of have been described in detail it would be apparent to a skilled addressee that many modifications and variations may be made. For example the upper track  16  may be made from two U-shaped channel members which are attached together, rather than as an integral continuous strip. This is exemplified in  FIG. 16  which shows a first upper track portion  16   a  having the flanges  52 , and a separate second upper track portion  16   b  that comprises the flanges  56 . A recess  196  is formed in the base  50  of portion  16   a  to receive the base  50   b  of portion  16   b . The portions  16  and  16   b  can then be connected together for example by spot welds or rivets for form an upper track which is substantially the same in configuration and function as the upper track  16 . In a further modification the first or lower side  31  of the panel  12 ,  12   a ,  12   b  may be formed with slots corresponding to slots  34   b  and  36   b  on opposite sides of inner sheet  24  and the lower track member  14  replaced with a further second track  16 . In yet a further modification the second or upper track  16  can be provided with only one of flanges  56   a  and  56   b  which is connected to the inner sheet  24 . In that modification the panel  12  can be correspondingly modified by being formed with only one of slot  34   b  and  36   b.    
     All such modifications together with others that would be obvious to persons of ordinary skill in the art are deemed to be within the scope of the present invention. 
       FIGS. 18 to 26  show a particular arrangement of a building system  10  according to a second embodiment of the invention. Reference numerals used to identify parts of the building system  10  in accordance with the previously described first embodiment of the invention are used to identify parts of the second embodiment to be described below that are similar to parts of the building system  10  in accordance with the first embodiment of the invention. 
       FIG. 18  shows a perspective view of the final form of a panel arrangement P comprising a first frame structure  200  (see  FIG. 25 ) and a second frame structure  202 . The frame structure  200  comprises bodies  204  and  206  that are joined at the opposing free ends by a track member  208  (defining a second track member) so as to form a further similarly configured door frame structure—see  FIG. 25 . Similarly, the structure  202  comprises bodies  210  and  212  that are joined at opposing (uppermost) free ends by a track member  214  (defining another second track member). The track members  208  and  214  are located at a second side (the upper side) opposite to the first side (of the panel P) that is attached to the first track member  14  (the lower track member  14 ). 
     Referring to  FIG. 21 , as shown in  FIG. 21 , the upper portion of the panel P comprises a pair of track members  208  and  214  sandwiching the inner sheet member  218 . In this manner the frame structures  200  and  202  are isolated with respect to each other through the inner sheet member  218 . 
     In the particular arrangement shown in the illustrated embodiment, the bodies  204 ,  206  and  210 ,  212  are configured as channel sections having flange portions  234  and  236  extending perpendicularly to a centre portion  238 —see  FIG. 24 . In alternative arrangements, the bodies  204 ,  206  and  210 ,  212  may not incorporate the flanges  234  and  236 . 
     The assembly of both door frame structures  200  and  202  in forming the panel P is shown schematically (showing various cross sections D and C, and associated detailed segments E, F, and G) in  FIGS. 19 to 23 , and in exploded form in  FIG. 24 . As clearly shown (see at least Detail E) body  202  is associated with a portion of a first edge E 1  (a lateral side of the panel  224 ) of the panel P so as to sit at or near the edge between the outer sheet member  216  and inner sheet member  218 , and the body  200  is associated with a further portion of edge E 1  so as to sit between the outer sheet member  220  and the inner sheet member  218 . Similarly, body  212  is associated at a portion of a second edge E 2  (a lateral side of the panel  226 ) of the panel P so as to sit at or near the edge between the outer sheet member  216  and inner sheet member  218 , and body  206  is associated with a further portion of edge E 2  so as to sit between the outer sheet member  220  and inner sheet member  218 . The space between bodies  210  and  212  is filled by the core material of the panel provided between the outer sheet member  216  and the inner sheet member  218 . Likewise, the space between bodies  204  and  206  is filled with core material provided between the inner sheet member  220  and the outer sheet member  218 . 
     The exploded view shown in  FIG. 24  lends itself to discussion of one embodiment of a method for making the panel P shown. In one such embodiment, the components shown in  FIG. 24  are placed in a mould or jig and positioned so that each are secured relative to each other during the injection and curing processes using, in this stance, suitable liquid reactants used to form the core material (which hardens to form a relatively solid core material) between the outer sheets  216 ,  220  and the inner sheet  218 . 
     In its simplest form, one method of forming a panel suitable for use with the assembly described herein may involve forming a building panel in a manner in which one of the first lateral side  224  or second lateral side  226  parts of the structural assembly  222  is associated with a portion of an edge of the panel when formed. Having regard to the embodiment of panel P, such a method may involve the first outer sheet member  216 , the second outer sheet member  220 , and the inner sheet member  218  being arranged in a mould or jig in a substantially spaced apart relationship, whereby the inner sheet member  218  is provided between the first and second outer sheet members. The respective bodies of the first lateral side  224  or second lateral side  226  can then be arranged between the appropriate first  216  or second  220  outer sheet members and the inner sheet  218  member at edge E 1  and/or edge E 2  of the panel P. 
     The bodies  204  and  206  are joined at opposing (uppermost) free ends by the track member  208  of a top track assembly TA configured at the top edge T 1  of the panel P; similarly, the bodies  210  and  212  are joined at opposing (uppermost) free ends by a second track member  214  of the top track assembly TA configured at the top edge T 1  of the panel P—see  FIG. 18 . Joining between meeting ends of track member  208  with bodies  204  and  206  and track member  214  with bodies  210  and  212  is by way of, for example, welding, however the skilled reader will readily appreciate other ways in which a sufficient connection/joining could be realised. 
     In order to provide the arrangement of the panel P shown in  FIGS. 18 to 24 , the components comprising the panel P may be arranged in a suitable mould or jig in substantially the manner shown in exploded form in  FIG. 24  (including the placement of spacer elements  228  to be discussed below). With the outer sheet members  216 ,  220  and inner  218  sheet member arranged relative one another, the frame structures  200  and  202  can be arranged, respectively, between outer  216  and inner  218  sheet members, and outer  220  and inner  218  sheet members. 
     Once the various components are suitably arranged in the mould or jig as required, liquid reactants can be delivered into the mould which react so as to produce a core material between the outer  216 ,  218 , and inner  218  sheet members. In practice, one or more holes may be provided in the inner sheet member  218  so as to enable the liquid reactants to flow between opposite sides of the inner sheet member. As the skilled reader will appreciate, forming the panel P in this manner allows the core material to form around the flange portions of the frame structures  200  and  202 . As shown, the dimension of the flange portions ( 234  and  236 ) of the channel sections of the frame structures  200  and  202  may be substantially equal. 
     As will be appreciated, forming in this nature allows for a panel to be produced having good physical (e.g., strength) characteristics and one which substantially forms or cures in an integrated manner. Furthermore, this construction process provides for a configuration in which the frame structures  200  and  202  becomes substantially integral with the panel P. 
       FIG. 24  show the spacer element  228  provided in the form of an elongate planar strip (of, for example, plastic material) of constant rectangular cross section extending a substantial portion along edges E 1  and E 2  of the panel P. As shown in detail E in  FIG. 23 , the spacer elements  228  are provided at the interface between the flange portions of bodies  202 / 200  and the respective outer ( 216 / 220 )/inner sheet members ( 218 )—thus, eight spacer elements  228  are used in panel P. 
     The spacer elements  228  are generally used for convenience in forming the panel and can offer some advantage when a single whole panel so formed is modified (e.g., cut in accordance with a specific height dimension) for installation purposes. For example, if a panel formed is to be cut in accordance with a specific height, the spacer elements  228  can be used as an indicator for assisting an operator in forming one or more further slots or recesses in, for example, the bottom edge of the panel P—such slots or recesses being used to receive or sit flanges of a bottom track member (positioned on a foundation of a building, for example, and to which the panel P is to be secured to). In practice, slots or recessed are typically formed in the panel by way of a grinding process and the spacer elements serve as sacrificial components so that the channel sections of the bodies  204 / 206 / 210 / 212  are not inadvertently compromised (i.e., in any manner which could have the effect of reducing their structural capacity) by any grinding action—instead, the spacer elements provide a sacrificial body when such modifications are made to the edges of a panel. 
     With reference to  FIG. 25 , a perspective view is shown of frame structure  200  having body  204  (comprising a plurality of male pairable parts  230 ) arranged in a parallel and opposing manner to body  206  (comprising a plurality of female pairable parts  232 ). 
     The male and female pairable parts  230  and  232  are adapted to be joined together. The pairable parts  230  and  232  permit joining together panels P that are located side by side to define walls structures of the building system. 
     As described with reference to the first embodiment of the invention, to construct a wall W, a user first fixes a lower track member  14  to a foundation of a proposed building, such as a concrete slab  62 , in any suitable way. One or more building panels P (in accordance with the second embodiment of the invention) are then engaged with the lower track members  14  (such as the lower track member  14  shown in  FIG. 26 ) by receiving the lower end of the panel P. In particular, the outer flanges  42  of the lower track members  14  are received by slots  238  defined in the lower side  236  (also referred to as the first side) of the panel P. In an alternative arrangement shown in  FIG. 26 , the lower track member  14  may include one or more inner flanges  43  located between the flanges  42  at a particular location that permits at least a slot  240  receive the inner flange(s)  43 . 
       FIG. 22  shows detail G of the cross section of the panel P shown in  FIG. 19 . As shown in  FIG. 22 , the lower side of the panel P comprise outer slot  238  and inner slot  240 . The outer slot  238  are defined between the outer sheet member  216  and core material  242 . The outer slots  238  are defined between the outer sheet members  216  and  220  and core material  242 . The inner slots  240  are defined between the inner sheet material  218  and the core material  242 . In the particular arrangement shown in the  FIGS. 18 to 25 , the slots  238  and  240  are defined by the fact that the spacers  228  are of reduced length with respect to the length of the panel P. By locating the spacers  228  in such an arrangement that an end of the spacers  228  do not reach the lower end  236  of the panel P a spacing is defined between the sheet members  216 ,  218  and  220  and the core material  242  forming the slots  238  and  240  for receiving the flanges  42  of the lower track. Alternative, the slots  238  and  240  may be formed though a grinding process as was described before. 
     The building panels  12  are fixed to the lower track members  14  in any suitable way, for example mechanical fasteners such as screws  64 . The screws  64  are driven through the first and/or second outer sheets  20 ,  22  into and through the respective adjacent flanges  42  and cores  26 ,  28 . The screws may be chosen to be of a length that does not penetrate to the inner sheet  24 . Although they may also be of sufficient length to extend through the inner sheet  24 . 
     The first embodiment of the invention has been described as including an upper track member  16 . In this first embodiment multiple building panels  12  and multiple upper and lower track members  14 ,  16  are provided with the multiple lower and upper track members  14 ,  16  disposed along a path of a desired wall in endwise relationship and multiple building panels disposed in endwise relationship between the lower and upper track members  14 ,  16  so as to define a wall. 
     In accordance with the second embodiment of the invention, there is provided a top track assembly TA (see  FIG. 18 ). The top track assembly TA is defined by the second track members  214  and  208  insulated with respect to each other through the inner sheet member  218 . 
     The previously described arrangements and shown in  FIGS. 18 and 24  incorporate frame structures  200  and  202  with their bodies joined at the second side (for example, the upper part). In other arrangements, the bodies of the frame structures may also be attached via a third track member at the first side (for example, the lower part). 
     All modifications together with others that would be obvious to persons of ordinary skill in the art are deemed to be within the scope of the present invention.