AU2016213856A1 - Building system and method - Google Patents

Abstract

The invention provides in one aspect a method of designing and constructing a building or building section to be located on a building site, the method comprising the steps of: designing a floor, walls and a roof of the building or building section, the step of designing comprising designing one or more rows of cassettes, each cassette being box-shaped and having six sides composed of six corresponding panels, the rows of cassettes forming at least a majority of an area of one of the floor, walls, and roof; manufacturing one or more of the corresponding panels of each cassette by machining from structural sheet or panel material using a CNC router controlled by a CADCAM system, the CNC router being in one aspect housed in a machining facility located away from the building site; assembling each of the cassettes; transporting the corresponding panels or assembled cassettes to the building site; locating a rigid frame on foundations at the building site; and constructing the floor, walls and roof on the rigid frame including installing the assembled cassettes into the designed rows. The invention also provides a building or building section constructed using the method and cassettes constructed using SIPS panels. 228$ 282- p o ~ 8$'N>N 288 O 281 ~~' 283 N 0 28 N287"'

Description

1 2016213856 12 Aug 2016

BUILDING SYSTEM AND METHOD FIELD

[0001] The present invention relates to building systems, in particular to a building system with improved labour efficiency.

BACKGROUND

[0002] Most modern homes are constructed from building materials sized and shaped on-site by skilled builders, which can be a slow process and involves in many countries relatively high pay rates compared with factory workers conducting more repetitive less skilled work. Modular construction is one way in which building can be made more efficient, lowering time on the work site. Most modular construction involves the construction of modules, typically room-sized, usually in a factory, and typically by conventional building techniques, and transporting the completed modules to the site for relatively rapid assembly.

[0003] Facit Homes of the UK (facit-homes.com) has pioneered a simplified on-site construction system involving computer-aided design of buildings which comprise the construction of walls, floors and roofs with rows of structural box sections called cassettes. The cassettes are constructed from sheets of structural grade plywood from which are cut out shapes using a CNC machine which are designed to be assembled into a hollow box shape, with appropriate holes and channels according to the requirements of the design. The cassettes are cut out on the building site using a relocatable CNC machine and assembled by the workers on site as required in the construction of the building. The simple joining of the cassettes into the constructed floor, wall or roof is straightforward and labour 2 2016213856 12 Aug 2016 saving in comparison to the inefficient measuring and sawing of individual structural components in conventional building. Also, the repeating units are designed to easily have pipe and cabling connections incorporated, decreasing the labour component associated with electricians and plumbers who are relatively expensive. Like modular construction, this process gains efficiencies through use of easily manufactured units which are easily assembled, but unlike modular construction has low transport costs because the repeating units are constructed on site from plywood sheets having efficient transportation characteristics of being easily stackable and dense in transportation.

[0004] One disadvantage of this type of construction using repeating units is the need for extremely narrow tolerances in the building foundations on which the floor rests in order to ensure that the pre-sized units fit together properly. Furthermore, the advantage of the use of on-site labour to construct the repeating units may be apparent in one country, but the economics may not be so favourable in another country where on-site labour is more expensive. Another disadvantage is that the cassettes can be expensive to construct.

[0005] There is therefore a need to provide a building system and method and associated components which offers a different mix of improving the construction process, minimising on-site labour costs and minimising off-site labour costs.

[0006] In one aspect of the invention, the inventor has realised that the cassette based repeating unit system can be adapted from its initially intended construction at the building site to form the basis of a highly efficient modular building system which improves efficiency away from the building site. 3 2016213856 12 Aug 2016

SUMMARY OF THE INVENTION

[0007] According to a first broad aspect of the invention there is provided a method of designing and constructing a building or building section to be located on a building site, the method comprising the steps of: designing a floor, walls and a roof of the building or building section, the step of designing comprising designing one or more rows of cassettes, each cassette defining a box shape and having faces and sides composed of corresponding panels, the rows of cassettes forming at least a majority of an area of one of the floor, walls, and roof; manufacturing one or more of the corresponding panels of each cassette by machining from structural sheet or panel material using a CNC router controlled by a CADCAM system, the CNC router being housed in a machining facility located away from the building site; assembling each of the cassettes; transporting the corresponding panels or assembled cassettes to the building site; locating a rigid frame on foundations at the building site; and constructing the floor, walls and roof on the rigid frame including installing the assembled cassettes into the designed rows .

[0008] In one embodiment, the step of assembling each of the cassettes is performed in a cassette assembly facility located away from the building site; the step of constructing the floor, walls and roof on the rigid frame is performed in a building construction facility located away from the building site, and 4 2016213856 12 Aug 2016 the step of transporting the corresponding panels or assembled cassettes comprises lifting each constructed building or building section containing the assembled cassettes on to a vehicle; and the step of locating the rigid frame on the foundations comprises lifting the constructed building or building section on to the foundations.

[0009] In another embodiment, the step of constructing each building or building section on the rigid frame is performed at least partly at the building site after the step of transporting and the step of locating.

[0010] In one embodiment, the method further comprises the step of constructing the rigid frame at least partly away from the building site, for example by constructing components away from the building site and then assembling the components on the building site to form the rigid frame.

[0011] In one embodiment, one of the building or building sections is a header-bearing building or building section and the step of designing in respect of a header-bearing building or building section comprises designing at least a header-bearing wall of the header-bearing building or building section to be composed of one or more rows of wall cassettes together with one or more header cassettes configured to be disposed on a top edge of the header-bearing wall, the header cassettes having attachment points configured to receive rafters of the roof. The step of designing in respect of the header-bearing building or building section may comprise designing the rafters to be provided by I-joists and designing the attachment point to be composed of a plurality of panels cut out from the structural sheet material to form fins with at least one gap therebetween adapted to receive a web of the I-joist. The step of designing 5 2016213856 12 Aug 2016 in respect of the header-bearing building or building section may comprise designing roof cassettes adapted to fit lengthwise between adjacent rafters and having overhanging topsides adapted to be fixed onto top surfaces of the rafters.

[0012] In one embodiment, the machining facility and the assembly facility are in the same location.

[0013] In one embodiment, the structural sheet material includes a structural grade engineered timber.

[0014] In one embodiment, the step of constructing the rigid frames comprises joining together steel components. The steel components may be joined by welding together the steel components .

[0015] In one embodiment, the rigid frame may be rigid base f rame.

[0016] In one embodiment, the rigid frame comprises lengths composed of engineered lumber; and the method further comprises the step of constructing the rigid frame by joining together lengths composed of engineered lumber using rigid connectors.

[0017] The lengths composed of engineered lumber may form columns in the walls and bearers in the floor, the columns and bearers being joined in the rigid frame along end to edge using rigid bearer to column connectors. One or more of the bearers or columns may comprise two lengths of engineered lumber joined together face-to-face at least through the bearer to column rigid connectors. The bearer to column rigid connectors may be sandwiched between the two lengths of engineered lumber of the one or more bearers or columns. 6 2016213856 12 Aug 2016 [0018] The lengths composed of engineered lumber may comprise rafters of the roof, the rafters and columns being joined end to edge using rigid rafter to column connectors. One or more of the rafters or columns comprises two lengths of engineered lumber joined together face-to-face at least through the rafter to column rigid connectors. The rafter to column rigid connectors are sandwiched between the two lengths of engineered lumber of the one or more rafters or columns.

[0019] In one embodiment, the method further comprises the step of joining together at least some of the lengths of engineered lumber in a frame manufacturing facility located away from the building site to construct one or more portal frames for transporting to the building site. This may further comprise the step of installing at least some of the assembled cassettes into the portal frames in a wall assembly facility located away from the building site to construct all or part of one or more of the walls .

[0020] In one embodiment, the method of constructing the roof comprises installing roof-adapted versions of the cassettes, the roof adapted versions having side panels shaped to provide a fall for drainage on a generally flat roof.

[0021] In one embodiment, the engineered lumber is laminated veneer lumber.

[0022] In one embodiment, the method further comprises the step of assembling one or more rows of the cassettes into a multi-cassette structure in a multi-cassette structure assembly facility located away from the building site, the multi-cassette structure being adapted to provide part or all of the roof, wall or floor. 7 2016213856 12 Aug 2016 [0023] In one embodiment, the step of manufacturing one or more of the corresponding panels comprises cutting an integral front and rear face panel unit from a SIPS panel using the CNC router, and constructing side panels from structural sheet material.

[0024] In accordance with a second broad aspect of the invention there is provided a method of designing a building and constructing a building or building section on a building site, the method comprising the steps of: designing a floor, walls and a roof of the building section, the step of designing comprising designing one or more rows of cassettes, each cassette defining a box shape and having sides composed of corresponding panels, the rows of cassettes forming at least a majority of an area of one of the floor, walls, and roof; manufacturing one or more of the corresponding panels of each cassette by machining from structural sheet or panel material using a CNC router controlled by a CADCAM system, by cutting an integral front and rear face panel unit from a SIPS panel using the CNC router, and constructing side panels from structural sheet material; assembling each of the cassettes; locating a rigid frame on foundations; and constructing the floor, walls and roof on the rigid frame including installing the assembled cassettes into the designed rows .

[0025] In accordance with a third broad aspect of the invention, there is provided a building or building section designed and constructed according to the method of the first or second broad aspects of the invention.

[0026] In accordance with a fourth broad aspect of the invention, there is provided cassette adapted for use in the 8 2016213856 12 Aug 2016 method of the second broad aspect of the invention, comprising an integral front and rear face panel unit cut from a SIPS panel, connected to side panels cut from a structural sheet material.

BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 shows a partially constructed building section according to an embodiment of the invention; [0028] Figure 2 shows an expanded view of the components present in the system of Figure 1; [0029] Figure 3 depicts the process of manufacture of cassette units utilised in the invention; [0030] Figure 4 shows steel frames forming a rigid base for the building sections according to the invention, arranged according to a floor plan for a building construction; [0031] Figure 5 shows floor cassettes in the process of installation into the steel frames of Figure 4; [0032] Figure 6 shows a fully installed floor in the steel frames of Figure 4; [0033] Figure 7 shows walls being constructed in one of the building sections of Figure 4; [0034] Figure 8 shows some completed walls and rafters installed; 9 2016213856 12 Aug 2016 [0035] Figure 9 shows roof cassettes being installed between the rafters; [0036] Figure 10 shows a flat roof section configuration; [0037] Figure 11 shows a pitched roof section configuration; [0038] Figure 12 shows details of construction of a header cassette of an embodiment of the invention; [0039] Figure 13 shows a part constructed frame of a simple one room building or a one rent building section according to a second embodiment of the invention; [0040] Figure 14 shows a further advanced almost complete stage of the construction of the rigid frame of the second embodiment; [0041] Figure 15 shows a further stage of construction of the second embodiment showing floor and Veranda construction; [0042] Figure 16 shows installation of wall base plates in the second embodiment; [0043] Figure 17 shows wall installation in the second embodiment; [0044] Figure 18 shows installation of cross-member rafters in the second embodiment; [0045] Figure 19 and Figure 19A show construction of the roof of the second embodiment; 10 2016213856 12 Aug 2016 [0046] Figure 20 shows an exploded view of the floor, walls and roof section of the second embodiment; [0047] Figure 21 shows details of construction of steel connector pieces and portal frames of the second embodiment; [0048] Figure 22 shows details of an alternative method of cassette construction according to an embodiment of the second and fourth broad aspects of the invention; and [0049] Figure 23 and Figure 24 show details of construction of a multi-cassette structural unit applicable to all broad aspects of the invention;

DETAILED DESCRIPTION OF EMBODIMENTS

[0050] Embodiments of the current invention will now be described.

[0051] Referring first to Figure 1, a partly constructed building section 1 according to the invention is shown, having a skillion roof. The floor 10 consists of hollow plywood box floor cassettes 12 constructed from structural sheet material inserted into a rigid steel frame base 11. Rigid steel frame base 11 is formed from welded steel sections and manufactured off site to the necessary tolerance and delivered on-site in a single piece. In this embodiment, the building section 1 is constructed on the building site from delivered cassettes such as 21, the cassettes being assembled as described below in an off-site facility and transported to the building site. In other embodiments building section 1 may be assembled into the state shown in Figure 1 offsite and transported complete with walls and roof and associated cassettes in place. Intermediate embodiments may involve partial construction of building section 1 off-site and finishing at the 11 2016213856 12 Aug 2016 building site. Short wall 20 consists of a single row of vertically aligned wall cassettes 21. Tall wall 30 consists of 2 stacked rows of similar vertically aligned wall cassettes 31 and 32. Skillion roof 40 connects to short wall 20 and tall wall 30 through header cassettes 50 and 55. Manufactured timber I-joist rafters 42 join to header cassettes 50 through fin-connectors 51, and roof cassettes 41 are installed between the rafters to form the roof.

[0052] Referring now to Figure 2, where an expanded view of components of Figure 1 is shown, rigid steel frame base 11 comprises border beams 15, 16 and inner cross beams 17. In this embodiment, the beams are welded together in a location away from the building site and the unitary rigid steel base frame 11 is transported to the building site. In other embodiments, beams may be manufactured to the required lengths away from the building site and delivered unconnected, and may be designed to be bolted together into a rigid steel base frame at the building site. In intermediate embodiments, two or more sub-unit frames may be constructed away from the building site and may be designed to be bolted together into a rigid steel base frame at the building site.

[0053] The floor is composed of multiple floor cassettes 12 resting on the cross beams 17. Wall bottom plate connector 15 is screwed or otherwise connected to an edge of the floor cassettes before installation of the short wall 20 composed of wall cassettes 21. Each wall cassette 21 comprises horizontal channels 23 useful for the installation of piping or wiring. In other embodiments, vertical channels can also be provided where wiring is required to travel vertically, or shallow wiring channels may be chased into the cassette panel during or after the construction of the cassette panel to be described. The wall cassettes 21 each comprise appropriately positioned recesses 22 12 2016213856 12 Aug 2016 for fastening the wall cassettes 21 together by fasteners such as staples to form the wall.

[0054] In walls such as the tall wall 30 in Figure 1, additional reinforcing may be required at various junctions between the cassettes, which can be provided by appropriate design of appropriate receiving recesses or channels structural metal or manufactured timber reinforcing elements, as will be apparent to a person skilled in the art. Each floor, wall and roof cassette also comprises circular frangible sections 13 which when punched out form appropriately sized holes (or circular holes ready formed) allowing thermal insulation to be blown into the cavity inside the cassette. Header cassette 50 is also constructed as a box from plywood sheet and in addition has rafter fin connectors 51 positioned and configured to engage with timber I-joist rafters 42.

[0055] Referring now to Figure 12, further detail of the header cassette construction of this embodiment is shown, both to show specific details of the header construction and details which are common to construction of floor and wall cassettes. Header cassette 50 comprises side walls 73, outside wall 70, inside wall 71, lower wall 72 and upper wall 74. Walls 70, 71, 72, 73 and 74 are assembled with the aid of the self-locating features of corresponding recesses and tabs such as recess 90 and tap 91, and recess 98 and tab 97. Reinforcing panel 75 assists in strengthening the assembled box shape between rafter fin connectors 51. Rafter fin connector 51 is composed of a total of 8 cutout sections of plywood stacked together, 6 of which comprise angular fin sections 81, 82, 83, 84, 85 and 86 and 2 of which are spaces to provide gaps 87, 88 for receiving the webs of two adjacent manufactured wood I-joists which are disposed side-by-side to form Rafter 42. Rafter fin connector 51 is anchored inside header cassette 50 by numerous tab and recess or 13 2016213856 12 Aug 2016 slot arrangements between fin sections and one or more walls, such as tab 92 and corresponding recess 93. Rafter fin connector 51 when assembled inside header cassette 50 protrudes through slots 94, 95, 96 in inner wall 71. As with the floor and wall cassettes, all the various side walls and cutout pieces of plywood panel are fixed together, typically with a nail gun or screw if necessary.

[0056] Analogous details as described above in relation to header 40 apply in relation to the principle of construction of wall, floor and roof cassettes which also preferably comprise self-locating tabs and recesses and are solely or predominately composed of cutout sections from plywood sheet.

[0057] Referring now to Figure 3, the process of the manufacture of the cassettes is outlined. Computer 60 runs computer-aided design and manufacture (CADCAM) software which enables computer-aided design of the building plan and size, shape and other characteristics of the associated cassettes and other building components, and enables transfer of the design data into routing instruction data for a CNC router 62. The building components relevant to the invention are the box cassettes constructed from structural grade sheet material 61, in this embodiment in the form of 1200 mm x 2400 mm x 19 mm structural plywood (cross laminated timber) manufactured to structural grade F-14 of the Australian and New Zealand building standards. Computer 60 is in data communication with CNC router 62 and sends routing instructions to CNC router 62, which then produces the individual self-locating parts from structural grade sheet 61.

The parts of this embodiment are self-locating by the incorporation of various tabs and corresponding recesses or notches to facilitate positioning. A semiskilled process worker in the factory then assembles the self-locating parts collected from one or several of the routed sheets 61 into an assembled 14 2016213856 12 Aug 2016 cassette 63, 64. It is anticipated that flexible robotic machines are now (at the current state of robotic technology) or soon will be readily configurable to assemble the cassettes, being a repetitive activity requiring no carpentry skills.

[0058] Referring now to Figure 4, three rigid steel base frames 16, 18, 19 are shown laid out on the building site ready for assembly of three corresponding building sections which the bases will support. The steel base frames are preferably installed on screw pile supports to minimise environmental impact, but may be installed on concrete stumps or any other suitable foundation. The foundation elements may engage the base frame at appropriate points on border beams 15, 16 and recessed crossbeams 17 where necessary to provide adequate support. The rigid steel base frames are manufactured off site, typically by welding lengths of steel together, to the required tolerance and rigidity. Each base frame is sized 4.2 m wide by 9.5 m long, which is a convenient length large enough to form convenient building sections but small enough to be transportable by truck. The base frame is advantageously less than 4.5 m in width which is the limit in Australia for transport with one escort. Wider base frames are possible for larger rooms but may require two escorts in transport. Being rigid and manufactured to the required tolerance, all that is required on site to ensure the correct geometrical alignment for construction of the building is relatively simple alignment of each base frame on the foundations. The rigidity and unitary construction of each base frame also allows for pre-assembly of each building section away from site and lifting by crane at lifting points on the base frame onto the truck tray where the building section is assembled away from the building site, and off the truck tray and into position on the foundations upon arrival of the truck at the building site. 15 2016213856 12 Aug 2016 [0059] Referring now to Figure 5, the process of installation of floor cassettes into the base frame simply involves dropping each cassette into place spanning across the spaced crossbeams 17 which are recessed into the border of the frame. The floor cassettes may be secured together if needed by staples located across matching recesses 22 discussed above. In another embodiment, floor cassettes 12 may be fastened onto cross beams 17 by the provision of wooden facing panels on a top surface of each cross beam into which wood fasteners such as screws or nailed may be fastened.

[0060] Figure 6 shows a state of completion of the installation of the floor cassettes into base frames 10, 18 and 19 to complete the floor (on which floorcovering of choice maybe eventually fitted).

[0061] Referring now to Figure 7, short wall 20 and the lower row of tall wall 30 is shown assembled. During construction of the walls, temporary bracing at intervals may be required which may be conveniently achieved by steel struts screwed into appropriate fixing points. Doorways are provided by designed gaps such as 25.

[0062] Referring now to Figure 8, the walls such as 20, 31, 32 are shown in a state of completion with headers and rafters 40 as previously described inserted into rafter fin connectors. Window openings 27 can be provided by gaps in a row of wall cassettes, and strengthening above the window openings can be provided at least in part by a row of longitudinal cassettes 27.

[0063] Referring now to Figure 9, partial installation of roofs using roof cassettes 41 is shown. Each with cassette 41 is of the appropriate length to fit inside the space between adjacent 16 2016213856 12 Aug 2016 rafters, and a top side of each with cassette comprises overhanging edges to allow fastening into tops of the flanges of the I-joists comprising each rafter. Standard roofing material such as corrugated iron, tiles or a weatherproof plastic membrane is then fixed to the upper side of the roof.

[0064] Referring now to Figure 10, an assembled building section having a semi-flat roof is shown, with header cassettes 55 and 56 being designed with fin connectors 57 and 58 appropriately positioned and oriented to generate the desired slope [0065] Referring now to Figure 11, angled I-beam joists 46 and 47 are shown as components of a pitched roof section. A reinforcing member 54 may be fixed between rafters 46 and 47 to maintain the design angle of the pitched roof. Such reinforcing member may be composed of steel plates bolted through on either side of the webs of the twin I-joists forming the rafters.

[0066] Referring now to Figures 13 to 24, an alternative embodiment is discussed where the rigid frame is composed of manufactured lumber. While the metal rigid base frame of the embodiment described above is useful, a potential drawback is that differential expansion compared to the lumber components may necessitate expansion joints and gaps. The embodiment of Figures 13 to 24 also discloses a rigid frame which extends beyond the base and enables construction of stronger portal frame structures.

[0067] Referring now to Figure 13, a part constructed frame of a simple one-room building or a one-roomed building section is shown. Foundations are in the form of rows of screw piles 101.

The rigid frame in this embodiment primarily comprises lengths of engineered lumber, forming bearers on the floor, columns in 17 2016213856 12 Aug 2016 the wall or rafters on the roof. The engineered lumber is laminated veneer lumber (LVL) supplied in 300 mm x 63 mm planks of length up to 9 m. Each plank may be cut to size on the CNC machine. Some of the bearers, columns or rafters such as 201, 207, 210, 208, 209, 203, 202 are joined together face-to-face to form double lengths of LVL through joining connectors to be described below. The joining connectors may also serve as a corner connector to provide a rigid right angle at the end to edge junction between bearer and column such as 205, or the end to edge junction between column and rafters such as 206. Others of the bearers, columns or rafters are single lengths of LVL, such as 211, 212, 213, 214. Some of the parts of the frame form portal frames such as 207, 208, 209, 210 which may be manufactured off site in separate facility. Other parts of the frame in this embodiment are steel columns 204 which are suitable for use where full-length windows are planned.

[0068] The rigid connectors to be described below are one part of the method by which the rigid frame is endowed with sufficient rigidity. Other joints may be rigidified using standard metal plate joiners as are known in the art.

[0069] It is desirable that the lengths of LVL timber are coated in a protective waterproofing coat such as latex paint having regard to the need for dimensional stability in the design concept of the invention, to prevent swelling due to moisture before lock-up stage in case of rain or delays. This applies mainly for on-site constructions where the cassettes are installed after the frame is constructed.

[0070] Referring now to Figure 14, a further advanced almost complete stage of the construction of the rigid frame is shown, in this case adding single lengths of LVL 220, 221 and 222 which form an edge of a Veranda. This illustrates that not all of the 18 2016213856 12 Aug 2016 beams, rafters or columns need to be double thickness, and the choice of alternatives will depend on design engineering requirements .

[0071] Referring now to Figure 15, installed into the frame in the Veranda section are short and thin lengths of LVL 230, 231, 232 to act as joists to support a wooden slat or other outdoor deck material. Figure 15 also shows completion of the internal floor using the rows of floor cassettes 233, 234 which may be exactly as described above or may be constructed according to an alternative equivalent but is more convenient construction described below.

[0072] Referring now to Figure 16, wall base plates such as 240, 241, 242, 243, 244 are installed to provide a base for the wall cassettes in parts of the structure which are to contain walls rather than windows .

[0073] Referring now to Figure 17, single rows of wall cassettes 250, 251 are shown installed forming the walls.

[0074] Referring now to Figure 18, cross-member rafters such as 260, 261, 262, 263, 264, 265 are shown installed on the roof, sized and positioned to accommodate and support ends of roof cassettes in between in three rows along the length of the roof.

[0075] Referring now to Figure 19, the roof cassettes such as 272 are shown installed together with horizontally extending roof battens such as 273, 274 ready for installation of roofing iron or other roofing material. The roof is designed with the required fall for drainage, and border cassettes 270, 271 provide a neat border. 19 2016213856 12 Aug 2016 [0076] Referring now to Figure 19A, design of the roof cassettes to provide the fall is shown. Uppermost cassette row 340 is upstream of middle cassette row 341, each having side panels with trapezoid shape appropriate to generate a linear fall in the roof line defined by roof battens such as 347, 378 located in recesses 345, 346. Position of the flat horizontal upper face of the cassette is revealed by locating holes such as 343, 344.

[0077] Referring now to Figure 20, an exploded view of the floor, walls and roof section is shown for further explanation of a number of features. Wall cassettes 280 are shown elevated above wall plate 288 on which the cassettes 280 rest. In embodiments described below where multi-cassette structures are described, the four wall panels together show installation may be provided in such a multi-cassette structure and installed all at once. Double beam bearer comprising first 286 and second 287 lengths of LVL are shown engaging with overhanging lip 281 of a top face panel of one of the floor cassettes, showing that the overhanging lip engages with the first length 286. Roof cassette overhanging lip 282 is shown in relation to cross-member rafter 283 positioned to support roof cassette through the overhanging lip 282. At opposite ends the roof cassettes rest on a drainage adapted roof header cassette 284 with a designed or added channel 285 adapted to receive an internal box gutter.

[0078] Referring now to Figure 21, details of the construction of the steel connector pieces and portal frames are shown. One version of the connector pieces is a corner or T-joint piece 299 which acts as a rafter to column connector adapted to connect together rafter lengths such as 295 with column lengths such as 293 end to edge. In the illustration, the corner or T-joint piece 299 also serves to sandwich together rafter lengths 294, 295 and column lengths 292, 293. The corner or T-joint piece 299 is fastened using bolts 303 extending through appropriately 20 2016213856 12 Aug 2016 positioned holes such as 302 in the LVL lengths. The corner or T-joint piece may also be used as a bearer to column connector or rafter to column connector is shown the diagram with overhanging rafter 306 and bearer 305 portions used in this embodiment in relation to the Veranda. Another version of the connector piece adapted for the bearers is shown as a piece 298 identical to 299 but also welded to base plate 304 adapted for attachment to the foundations.

[0079] Referring now to Figure 22, details of an alternative method of cassette construction illustrating another broad aspect of the invention are provided. The inventor has realised that the cassette arrangements can be very conveniently and cheaply provided by manufacturing the top and bottom faces of the cassette by cutting an integral front and rear face panel unit from a SIPS panel (Structural Insulated Panel System) which is a large pre-supplied panel of manufactured lumbar sheets such as oriented strand board sandwiched between polystyrene, polyurethane or other insulation. In the diagram, the front and rear face panel unit can be seen composed of front face 310 and rear face 320 formed in the CNC machine from a SIPS panel with appropriate locating holes in recesses such as 318 and 319 as described above, and insulation 311 which has been cut at the edges by the CNC machine to provide any appropriate overhangs of the front 310 and rear 320 faces. Side panels 312, 313, 314, 315 appropriate tabs such as 317, 316 are shown, manufactured as described above on the CNC machine. There are substantial cost advantages associated with constructing the cassettes this way, and in addition the insulation is ready installed. There are also advantages over standard SIPS panel construction whereby the extra strength of the box cassettes structure improves the versatility and uses of SIPS panels in the building.

[0080] Referring now to Figure 23, details of an additional 21 2016213856 12 Aug 2016 labour saving technique is described, whereby one or more rows of cassettes can be formed into multi-cassette structural units in a multi-cassette assembly facility located away from the building site if desired. In the diagram two rows 330, 331 of four cassettes each are joined using LVL lengths 332, 333, 334, 335, 336, 337 into a single structural unit shown assembled in Figure 24. This can be used as all or part of a floor, wall or roof. The cassettes used in the construction can be of the SIPS panel type described above or of the type described in the first embodiment, or any other type.

[0081] It may be advantageous for the cassettes of all embodiments to be coated in a waterproofing layer, such as latex paint, EPDM rubber or bituminous compounds, to allow for tolerance to temporary weathering and exposure to water during construction. It may further be advantageous to apply waterproof coating to an entire panelized wall, floor or roof section consisting of many assembled components that form a large area for entire modules forming all or part of a building.

[0082] The invention comprises in its first broadest sense a reimagining of the role an existing cassette based system, to transfer the site of manufacture of at least panels of each cassette away from the building site to machining facilities and assembly facilities which are well suited to high-efficiency operation using relatively less skilled and less expensive labour, thus increasing the productivity both away from and at the building site. The rigid frame of each building or building section, also in some embodiments of the invention enables entire modular building sections to be constructed away from the building site and easily lifted and transported, and in other embodiments of the invention allows parts the frame to be constructed off-site as portal frame elements. Further off-site assembly may be achieved using integral multi-cassette 22 2016213856 12 Aug 2016 structures. It is envisaged the cassette assembly process will also lend itself to further productivity improvements by robotic automation much more readily, being located in a well-controlled assembly facility.

[0083] Persons skilled in the art will also appreciate that many variations may be made to the invention without departing from the scope of the invention, which is determined from the broadest scope and claims.

[0084] For example, in its broadest aspects the invention allows that there will be some building sections in parts of the building which are not constructed according to the building sections of the invention, and even only one building section may be so constructed.

[0085] It will be understood that the different facilities away from the building site described and claimed may all be in the same location away from the building site, and are differently named in order to allow for the possibility of separate location.

[0086] Although the embodiments described show cassettes with a complete set of two faces and four sides, which are preferred in most applications, cassettes within the broadest scope of the invention do not require all four sides to be covered with panels and for example may include cassettes with only two opposite sides having panels and another two opposite sides missing. Further, it will be appreciated that the box shape is defined by the junction of the sides and faces and does not need to be a rectangular prism in the broadest aspects. Also as described above many of the cassettes have extensions on faces and sides outside the box shape for various functional purposes 23 2016213856 12 Aug 2016 including attachment and placement for example the extended sides of the roof cassettes providing the roof fall.

[0087] In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention. Further, any method steps recited in the claims are not necessarily intended to be performed temporally in the sequence written, or to be performed without pause once started, and may be performed together as described above or otherwise, unless the context requires it.

[0088] Throughout this specification and the claims, the term "cassette", including "wall cassette", "floor cassette", "roof cassette" and "header cassette" and similar is intended to refer to types of the cassettes as defined in the claims.

[0089] Throughout this specification, the term "self-locating panels" means panels which fit together in their intended interrelationship with the aid of recesses, tabs, protrusions, matching profiles and the like.

[0090] Throughout this specification and the claims, the term "CADCAM system" means any system, integrated or in separate parts, which incorporates computer-aided design and generation of computer-aided manufacturing instructions for a CNC machine.

[0091] Throughout this specification and the claims, the term "roof" includes an inside-facing ceiling portion of a roof 2016213856 12 Aug 2016 24 structure as well as an outside-facing roofing material, except where the context requires otherwise.

[0092] It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

Claims (30)

1. A method of designing and constructing a building or building section to be located on a building site, the method comprising the steps of: designing a floor, walls and a roof of the building or building section, the step of designing comprising designing one or more rows of cassettes, each cassette defining a box shape and having faces and sides composed of corresponding panels, the rows of cassettes forming at least a majority of an area of one of the floor, walls, and roof; manufacturing one or more of the corresponding panels of each cassette by machining from structural sheet or panel material using a CNC router controlled by a CADCAM system, the CNC router being housed in a machining facility located away from the building site; assembling each of the cassettes; transporting the corresponding panels or assembled cassettes to the building site; locating a rigid frame on foundations at the building site; and constructing the floor, walls and roof on the rigid frame including installing the assembled cassettes into the designed rows .

2. The method of claim 1, wherein: the step of assembling each of the cassettes is performed in a cassette assembly facility located away from the building site; the step of constructing the floor, walls and roof on the rigid frame is performed in a building construction facility located away from the building site, and the step of transporting the corresponding panels or assembled cassettes comprises lifting each constructed building or building section containing the assembled cassettes on to a vehicle; and the step of locating the rigid frame on the foundations comprises lifting the constructed building or building section on to the foundations.

3. The method of claim 1, wherein the step of constructing each building or building section on the rigid frame is performed at least partly at the building site after the step of transporting and the step of locating.

4. The method of claim 1, further comprising the step of constructing the rigid frame at least partly away from the building site.

5. The method of claim 4, wherein the step of constructing the rigid frame at least partly away from the building site comprises constructing components away from the building site and then assembling the components on the building site to form the rigid frame.

6. The method of claim 1, further comprising the step of constructing the rigid frame away from the building site.

7. The method of claim 1, the building or building section is a header-bearing building or building section and the step of designing in respect of the header-bearing building or building section comprises designing at least a header-bearing wall of the header-bearing building or building section to be composed of one or more rows of wall cassettes together with one or more header cassettes configured to be disposed on a top edge of the header-bearing wall, the header cassettes having attachment points configured to receive rafters of the roof.

8. The method of claim 7, wherein the step of designing in respect of the header-bearing building or building section comprises designing the rafters to be provided by I-joists and designing the attachment point to be composed of a plurality of panels cut out from the structural sheet material to form fins with at least one gap therebetween adapted to receive a web of the I-joist.

9. The method of claim 7, wherein the step of designing in respect of the header-bearing building or building section comprises designing roof cassettes adapted to fit lengthwise between adjacent rafters and having overhanging topsides adapted to be fixed onto top surfaces of the rafters.

10. The method of claim 1, wherein the machining facility and the cassette assembly facility are in the same location.

11. The method of claim 1, wherein the structural sheet material includes a structural grade engineered timber.

12. The method of claim 1, wherein the step of constructing the rigid frame comprises joining together steel components.

13. The method of any one of claims 1 to 12, wherein the rigid frame is a rigid base frame.

14. The method of claim 1, wherein the rigid frame comprises lengths composed of engineered lumber; and further comprising the step of constructing the rigid frame by joining together lengths composed of engineered lumber using rigid connectors .

15. The method of claim 14, wherein the lengths composed of engineered lumber form columns in the walls and bearers in the floor, the columns and bearers being joined in the rigid frame end to edge using rigid bearer to column connectors.

16. The method of claim 15, wherein one or more of the bearers or columns comprises two lengths of engineered lumber joined together face-to-face at least through the bearer to column rigid connectors .

17. The method of claim 16, wherein the bearer to column rigid connectors are sandwiched between the two lengths of engineered lumber of the one or more bearers or columns.

18. The method of claim 14, wherein the lengths composed of engineered lumber comprise rafters of the roof, the rafters and columns being joined end to edge using rigid rafter to column connectors .

19. The method of claim 18, wherein one or more of the rafters or columns comprises two lengths of engineered lumber joined together face-to-face at least through the rafter to column rigid connectors .

20. The method of claim 19, wherein the rafter to column rigid connectors are sandwiched between the two lengths of engineered lumber of the one or more rafters or columns.

21. The method of any one of claims 14 to 20, further comprising the step of joining together at least some of the lengths of engineered lumber in a frame manufacturing facility located away from the building site to construct one or more portal frames for transporting to the building site.

22. The method of claim 21, further comprising the step of installing at least some of the assembled cassettes into the portal frames in a wall assembly facility located away from the building site to construct all or part of one or more of the walls .

23. The method of any one of claims 1 to 22, wherein the method of constructing the roof comprises installing roof-adapted versions of the cassettes, the roof adapted versions having side panels shaped to provide a fall for drainage on a generally flat roof.

24. The method of any one of claims 14 to 23 wherein the engineered lumber is laminated veneer lumber.

25. The method of any one of claims 14 to 24, wherein the step of assembling each cassette is performed for at least some of the cassettes in a cassette assembly facility located away from the building site.

26. The method of claim 1 or claim 14, further comprising the step of assembling one or more rows of the cassettes into a multi-cassette structure in a multi-cassette structure assembly facility located away from the building site, the multi-cassette structure being adapted to provide part or all of the roof, wall or floor.

27. The method of any one of claims 1 to 25, wherein the step of manufacturing one or more of the corresponding panels comprises cutting an integral front and rear face panel unit from a SIPS panel using the CNC router, and constructing the remaining four corresponding panels from structural sheet material.

28. A method of designing a building and constructing a building or building section on a building site, the method comprising the steps of: designing a floor, walls and a roof of the building section, the step of designing comprising designing one or more rows of cassettes, each cassette defining a box shape and having faces and sides composed of corresponding panels, the rows of cassettes forming at least a majority of an area of one of the floor, walls, and roof; manufacturing one or more of the corresponding panels of each cassette by machining from structural sheet or panel material using a CNC router controlled by a CADCAM system, by cutting an integral front and rear face panel unit from a SIPS panel using the CNC router, and constructing side panels from structural sheet material; assembling each of the cassettes; locating a rigid frame on foundations; and constructing the floor, walls and roof on the rigid frame including installing the assembled cassettes into the designed rows .

29. A building or building section designed and constructed according to the method of any one of claims 1 to 28.

30. A cassette adapted for use in the method of claim 28, comprising an integral front and rear face panel unit cut from a SIPS panel, connected to side panels cut from a structural sheet material.