WO1992022716A1 - Modular building construction - Google Patents

Abstract

A modular building construction incorporates planar triangular end parallel chord trusses where chords (101, 201) define the perimeter of the trusses and stability is provided by braces (102, 202) which do not cross. Each chord (101, 201) and brance member (201, 202) has a pivotal joining hole (222, 232) near both ends of each member and are pivotally attached one to the next via circular pins (250) through the holes. Braces do not cross one over the other. This allows pivoted rotation between all members in the plane of the truss (7202) or frame (7201) where this type of joint arrangement is referred to as a single pin mode. Parallel trusses (7202) may be interconnected by two or more lateral trusses (7201) and eccentricities may be incorporated into the trusses.

Description

Title: "MODULAR BUILDING CONSTRUCTION" BACKGROUND OF THE INVENTION

(1) Field of the Invention

THIS INVENTION relates to improvement in buildings,including structural components, methods of construction and functionality of the finished building. Primarily the invention will provide a syste ized, modular building construction method, capable of significantly reducing both the cost, and construction times for a large range of building types.

(2) Prior Art

A thorough investigation of building construction methods and systems prior to the drafting of this patent has revealed there is ample scope for improvement, over existing methods and systems, and the existing state of the art is summarized as follows:

(a) Many buildings and structures are designed and constructed as "one off" projects, where the benefits of productions runs and the economies of scale are sacrificed. This results in added expense and time delays due to the inevitable detailed communication and conversion of ideas into finished products. This teaching and learning process for "one off" buildings is often frustrated by fragmented designs, where architects, structural engineers, electrical and hydraulic consultants work from independent offices. There is also of course more scope for costly and time consuming mistakes in both design and construction where many details are original designs in a "one off" project.

(b) Where modular construction systems are used many are characterized by having features which are instantly recognizable as modular or "kit" form construction, which unfortunately can carry with it a stigma of cheap or second rate construction. Most "kit built" or "system built" buildings are inflexible in the use of different materials and are limited in design flexibility. Almost without exception "kit built" or "system built" buildings fail to have the aesthetic features and appeal of "one off" purpose built buildings.

(c) In both system built and "one off" construction, different components of the buildings are designed to depend on each other, to the detriment of these components performing in the most efficient way and to the detriment of the building having optimum functionality. For example in the majority of single storey residential buildings the floor slab supports the walls, which in turn support the roof. If the roof was designed to be an independent structure, the floor slab and walls could also be independent^' since they don't need to carry the roof loads. This leads to economies in floor and wall design and allows greater functionality of the building because the walls can be easily relocated to suit changing needs.

(d) Building construction methods in both

"one off" and system built buildings, invariably have their construction time schedules determined by on site trade dependency, where for example the roof cannot be erected before the walls, or the electrician waits for the plumber to install a hot water system and so on.

Trade dependency on site and the failure to use concurrent factory and site construction can easily double the construction period of a project. Trade dependency on site could be greatly reduced by producing fully equipped bathroom modules, for example, or prefabricated independent walls, where this site trade dependency is transferred to a factory situation, and is concurrent with other site trade dependencies, thereby greatly reducing construction times. This time saving is of course critical, especially where annual construction periods are limited by rain, snow etc.

(e) Construction methods usually employ a sequence of construction where the roof is erected towards the middle or near the end of the construction period, which means that the period before the roof erection is subject to time delays because of rain, snow, wind, harsh sunlight etc.

(f) In many cases the roof designs for buildings, because they are not considered as independent structures, tend to become "add hoc", using support locations determined by building layouts, without much concern for the efficiency of the roof structure itself. In most cases too many supports are used which makes future renovations both difficult and expensive.

(g) The construction of roofs is almost without exception carried out in its final elevated position. This means working at heights and the necessary and expensive safety precautions are added to the cost of construction, as well as crane costs for larger roof components.

(h) Where prefabricated components are used in "system built" buildings, they are often incorporated or built in" to the structure without any concern for easy disassembly, for relocation.

(i) The use of underground services within the plan area of the building involves unnecessary time delays due to trade dependencies during construction and of course makes renovation very difficult.

(j) The provision of services, such as drainage and air-conditioning in multi-level buildings involves the necessity of false or suspended ceilings and the complications of shared ownership of space, for repair of services, involves both legal and cost considerations.

(k) "System built" and "kit built" buildings still require the use of very significant amounts of skilled trade work, which has a major effect on building costs, particularly in remote areas.

(1) The use of prefabricated steel trusses in buildings for roof and wall components has over recent years become popular, however there remains much room for improvement in joint design and a simple site assembled systemised truss, suitable for easy transport is yet to be produced.

(m) Where prefabricated steel trusses are used in buildings they are of two types i.e. welded or bolted, each with its own advantages and disadvantages, however they both use rigid joint designs, which means inefficiencies in member sizing because of induced bending moments, and they both require specialist installation, particularly larger bolted trusses where friction grip bolting in gusset plate joints is used. None of these trusses use simple single pin connections for pivotal joints.

(n) Truss design in buildings is relatively unsophisticated in structural engineering principles. Cost savings are not yet available by using prestressing principles induced by varying member lengths in the truss, and cost effective designs have not yet been developed to accommodate loads placed on truss members between node or joint locations.

SUMMARY OF THE INVENTION With all of the above in mind the preferred objects of this invention are as follows:

(a) To provide a modular construction system, easily understood by all sections of the building industry,including architects, engineers, tradesman and end users, which is capable of offering significant cost and construction time savings in a wide range of building types.

(b) To provide a modular construction system, which not only offers a cost and time saving, but does so, not at the expense of aesthetics or design flexibility, a system in which a wide range of materials and design styles can be used so that the buildings are not immediately recognizable as "system" or "kit" built.

(c) To provide a modular building construction system, in which the structural dependency of various separable parts of the building is reduced to an absolute minimum, such that each separable part, including the roof, floor, walls and furniture all have the benefit of economies in design and/or construction methods, and in particular where the walls are non- load bearing and relocatable for increased functionality to suit changing needs.

(d) To provide a modular building construction system, where concurrent "on site" work and factory prefabrication of the building components substantially reduces total construction time, and where "on site" trade dependency is reduced to a minimum by maximizing trade dependant construction into factory supervised prefabricated components, to the extent of constructing completely fitted out rooms, in the factory, in particular wet area modules such as bathrooms and laundries where trade dependency is high.

(e) To provide a modular building construction system, incorporating a construction sequence where the roof is constructed first in the sequence, thereby allowing all other work to be carried out under cover, which reduces total construction time and reduces "on site" trade dependant operations e.g. services can be run in the roof space at the same time as a concrete floor slab is poured. (f) To provide a modular building construction system, in which the roof is designed as an independent, stand alone structure, where an absolute minimum number of column supports can be used because of a very efficient form of frame construction, using intersecting trusses, which enhances the functionality of the total structure and substantially reduces the cost of renovations, and where the space inside the roof frame may be used as living area. (g) To provide a modular building construction system, in which the roof or floor system is constructed at or near ground level, including the installation of all roof sheeting, ceiling, facias, gutters, -gable ends, vents, insulation and services, and then lifted and fixed in its final location on a minimum number of support columns, which are also used to support temporary lifting equipment, where this method of construction is safer and more cost effective than elevated construction. (h) To provide a modular building construction system which allows easy disassembly for relocation, reassembly and erection, using another set of support columns at a different location.

(i) To provide a modular building construction system in which services are run within the roof space for reticulation to the area below, where all services in a single storey dwelling can be eliminated from being underground, by running drainage discharge through the walls and roof space using small macerator pumps, and small diameter pipes and where the support columns also serve as service ducts.

(j) To provide a modular building construction system for multi-level buildings in which combined floor/ceiling units are constructed at or near ground level, including all services and are lifted and fixed to columns supports prior to the installation of prefabricated walls.

(k) To provide a modular building construction system, designed to be easily understood and assembled by unskilled labour, which will reduce construction costs particularly in remote areas.

(1) To provide a modular building construction system, which incorporates simple, easily transported, site assembled steel trusses and frames as the basic structural components of the system, where the trusses are easily fabricated from standard steel sections, and three dimensional frames are assembled by fixing together intersecting trusses in different planes. (m) To provide a modular building construction system, incorporating significant improvements in structural design of the basic trusses in the system, by using simple single pin joints to replace welded or multiple bolt joints, where the geometry of the trusses using these single pins is such that length fabrication tolerances of the components is not critical for correct load sharing in the truss.

(n) To provide a modular building construction system, in which the trusses in the system have some members which can be adjusted in length, such that beneficial eccentricities or prestressing can be introduced into the building structure.

The scope of the invention is defined in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

To enable the invention to be fully understood, preferred embodiments will now be described with reference to the accompanying drawings, in which:

FIGS. 1 to 61 illustrate planar truss geometry and joints of the invention; FIGS. 62 to 71 illustrate three-dimensional frame geometries and joints of the invention; and

FIGS. 72 to 89 illustrate building structures, in accordance with the invention, and their possible uses.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 and 2 are diagrammatic representations of planar trusses, being elevations of a triangular truss in FIG. 1. and a parallel chord truss in FIG. 2. Those members forming the perimeter of the truss are called chords and are shown as members 101 in FIG. 1. and 201 in FIG. 2. Those members contained within the perimeter, and not forming any part of the perimeter are called braces, because they brace or add planar stability to the truss. The braces are shown as members 102 in FIG. 1. and 202 in FIG. 2. Each of the chord or brace members 101, 102, 201, 202 are straight, elongated structural members, capable of carrying axial compression and tension loads, and each member has a hole near each of its ends, at or near 90 degrees to its longitudinal axis, where these holes are represented by the circles in FIGS. 1 and 2. One method of forming the trusses shown in FIGS. 1 and 2 is shown in the exploded isometric view in FIG. 2A, this FIG., being a typical joint or node represented by the circles in FIGS. 1 and 2. In FIG. 2A. chords 220 have a longitudinal axis 221 and holes 222 at or near 90° to, and on the axis, and braces 230 have a longitudinal axis 231 and holes 232 at or near 90° to, and on the axis. The joint or node is assembled along the axis 240 and clamped together using the common joining pin 250 and securing nuts 251 which screw onto a threaded section of the pin 252. This node type is referred to as a single pin node. All chords-ad braces in FIG. 2A are angle sections having at least one face for co- planar abutment with other members, under the clamping action of the pin and nuts. It can be seen from FIG. 2A that the use of the single pin allows pivotal rotation of all members about the pin, provided the clamping action does not cause a frictional binding force between the members which would prevent rotation. It is important to note that this pivotal action about the single pin, which allows a variation of the planar angle between any two members at the node, when considered in conjunction with the triangulated brace arrangement in FIGS. 1 and 2, allows that the distance between hole centres in any member is not geometrically critical for assembly of the truss to occur. If a member were fabricated which was slightly longer or shorter than the calculated length for a given truss geometry, assembly is still possible and easily understood by considering the truss as a progressive assembly of individual triangles commencing at one side of the truss and finishing at the other side, where each individual triangle does not have any critical length features, provided the angles between members can be varied. Therefore an assembled truss as in FIGS. 1 and 2 will function basically as designed, in terms of load carrying capacity even if a slightly incorrect length member is included. Other structural features of the trusses depicted by FIGS. 1, 2 and 2A are that members will not develop any bending moment, provided the applied loads and supports are at the nodes, and that load transfer from one member to adjacent members at the node is accomplished by shear action in the pin. Also it can be seen from FIG. 2A that other structural section shapes could be used as the chords or braces, provided co-planar abutment and pivotal rotation is available between members. FIG. 3 is an exploded isometric view of a typical node which could be used in FIGS. 1 and 2, where the chords 301 and braces 302 are assembled along the axis 303 and clamped together using a single pin and nuts (not shown) as in FIG. 2A. FIG. 3 shows that by mitre cutting the ends of the channel section chords and braces, pivotal connection between members can be achieved. FIG. 3A is an elevation of the joint or node showing clearances available for pivotal rotation. Other structural section shapes which could use this principle are lipped channels, Z and lipped Z sections, angles and I sections.

FIGS. 4, 5, 6 and 6A show other methods of achieving pivotal rotation between members at the nodes. In the isometric view of FIG. 4 the end of the channel section chord or brace has been flattened or reshaped to form a planar face about the pivotal connection hole. The area of planar face so created about the hole can be large enough to allow an almost unrestricted amount of rotation between members. FIGS. 5 and 6 are plan views of the channel in FIG. 4 and show that the plane of contact with other members, can be created behind the web of the channel in FIG. 5 or in front of the web of the channel as in FIG. 6 such that a beneficial planar offset of distance B in FIG. 5 or distance A in FIG. 6 allows more effective load carrying capacity in the channel, depending on the type of forces created in the channel, by different load locations and directions, e.g. FIG. 5 with a planar offset behind the plane of the web is more efficient in carrying bending moment loads, whereas the planar offset in FIG. 6 being in front of the web plane is more efficient in carrying axial 25 loads.

In FIG. 6A the channel section chords 601 have had parts of their flanges removed in the vicinity of the pivotal connection hole such that the channel braces 602 can be rotated with respect to the chords 601 about the assembly axis 603.

Returning now to FIGS. 2A, 1 and 2, it also needs to be pointed out, particularly in view of the explained non-critical length geometry between hole centres, that a much closer tolerance between the diameter of the pin 250 and the diameter of the holes 222 and 232 is also possible, where this pin to hole tolerance is also not a critical factor in allowing the truss to be assembled.

In other words because the trusses in FIGS. 1 and 2 can be assembled as progressive non-critical length individual triangles, the pin to hole tolerance can be much closer than is normally allowed in structural fabrication work. This means that truss deflections attributable to pin to hole slop can be minimized under load reversals, to such an extent that using a hole to pin diameter ratio of 1.01 or less, which has been found to be entirely practical, reduces the truss deflection caused by pin to hole slop, as compared to allowable structure deflection, to a negligible amount.

FIGS. 7 and 8, being sectional elevations of nodes where common joining pins provide pivotal connection between members, shows the use of tapered pins, to further reduce pin to hole diameter ratios. In FIG. 8, two channel chords 801 have the same hole size and a tapered pin 802 is used to join them. The tapered pin 802 has a slightly bulbous section 803 formed at its end and a threaded section 804 at its other end. By inserting the pin through the holes in the channel chords and clamping them together using a washer 805 and nut 806, the tapered diameter pin is pulled through the holes until the diameter of the pin is equal to the diameter of the hole in one chord. Provided the bulbous section of the pin 803 is not part of the taper and the taper is in the range of 1 in 100 to 1 in 200 most practical nodes with up to members joined at a common pin, can achieve a maximum hole to pin 30 diameter ratio of 1.005 or less in every member.

FIG. 7 shows the use of two tapered pins on a common axis. The pins and details are similar to FIG. 8 and the node details are explained later in the specification.

FIGS. 9, 10 and 11 show details of the pin used to join members at the node. The details should also be read in conjunction with FIG. 2A, where the prime purpose of the pivotal connecting pin was explained as providing a means of transferring loads from member to member across the node, by shear action in the pin. To achieve this the members have to be clamped together with sufficient force to maintain co-planar contact between member faces, but not enough force where frictional resistance would prevent pivotal rotation. Now it can be seen from FIG. 2A, that this clamping action provided by the screw threads and nuts also provides a secondary beneficial action, in that it will provide a degree of lateral structural rigidity or continuity across the node in planes parallel to the pin, the amount of rigidity depending both on the clamping force provided by the pin and nuts, and the lateral structural rigidity of the members co-planar faces in the vicinity of the connecting pin. In order to achieve the shear transfer function, lateral rigidity, and close hole to pin diameter tolerances, it is necessary for the threaded sections on the pin, not to be in the shear planes between any two members, also the lack of redundancy when using a single pin, warrants that the pin design must have a means where visual inspection will ensure that the assembled node and in particular the pin will perform the functions required of it. FIGS. 9, 10 and 11 show how a visual inspection of the assembled node can ensure that the holes in the members bear on the unthreaded section of the pin. In FIG. 9 which is an exploded isometric view of the pin assembly, the pin 901, has a threaded section 902 at each end, washers 903 and nuts 904. FIG. 11 shows a disassembled joint where it can be seen the diameter of the holes in the washers 903 and members 905 is only slightly larger than the unthreaded section of the pin 901 and the threaded sections on the pin are of a smaller diameter. In the assembled joint FIG. 10 it can be seen that by using a pin with the same length as the total combined widths of the nuts, washers and members, a visual inspection of the ends of the pin being flush or nearly flush with the outside face of the nuts 9 0 4 will ensure the members are bearing on the unthreaded section of the pin. FIG. 12 introduces the concept of some members having more than one planar face for co-planar abutment with other members. In this case two different sized square hollow sections are telescopic, one within the other, but with some clearance for pivotal rotation and the node is assembled along the axis 1204. By using one common pin to assemble the chords 1201 and 1202 and the braces 1203 it can be seen that lateral structural rigidity is achieved from chord to chord without the need of the clamping action of the pin, however the braces will need the clamping action for lateral structural rigidity. Also it can be seen in FIG. 12 that by using only one brace on each side of the laterally separated faces of the square hollow section chords, that a twisting tension will be introduced at the node. FIG. 12A is a variational FIG. 12 where torsion in the joint can be eliminated by using double braces 1211 and 1212, with channel chords 1213 and a square hollow section chord 1214, assembled along axis 1215. FIGS. 12A and 13 introduce the concept of double members in the same relative planar location, to provide torsion free nodes when used in conjunction with members with more than one planar face e.g. as shown in FIG. 13 the square hollow section chord 1301 and braces 1302 and 1303. The double chords 1304 also have aligned holes in the same relative planar location, to allow assembly using common pins 1305 and nuts 1306 to join the channels to other members and each other along axes 1307. FIG. 13 also shows the use of tubular spaces 1308 which fit over the pins 1305 and between the internal faces of the square hollow section chord 1301. This ensures that the clamping action of the pin will not deform these faces and that the end bearing load placed on the surface area of the holes in the chord 1301, by the pin 1304 will not cause the face to prematurely deform inwards. The use of these tubular spaces provides a "restrained" joint, which has a far greater load carrying capacity than an "unrestrained joint". FIGS. 14 to 19 show various means of strengthening the double members in the same relative planar location shown in FIGS. 12A and 13, by providing a means of joining the individual members at one or more locations between the nodes. This will give the double members load carrying capacities in excess of the summation of the load carrying capacities of each member. In FIG. 14 the square hollow section chord 1401 is joined to double chord channel sections 1402 and double brace angles 1403. A strengthening square hollow section 1404 can be fixed between the double channels using bolts through holes 1405 in the square section 1404 and oversize holes 1406 in the double channels 1402. The reason for using oversized holes in the double channels is to preserve the non-critical assembly feature of the whole system, however if oversized holes are used the strengthening section 1404 only strengthens the double channels in the Y direction (refer standard engineering texts) and not in the X direction. To achieve strengthening of the double channels in the X direction it would be necessary to use close tolerance holes by drilling the double channels 1402 and strengthening section 1404 together. Of course the double angle braces 1403 can be similarly strengthened using section 1407. Another method of providing additional strength to the double channels is shown in FIG. 15, where the double channel 1402 is plug welded to the section 1404 through the holes 1406 in the channels.

FIGS. 16 and 17 are to be read together where FIG. 16 is an isometric view and FIG. 17 is a sectional elevation of another strengthening means for the double channels 1601, where a pressed metal section 1602 fits over the channels and is held in place by bolts and nuts 1603, thereby providing buckling restraint in the Y direction, and additional bending strength to the channels in the X direction if the pressed section 1602 were bolted to the flanges of the double channels.

FIGS. 18 and 19 are similar to FIGS. 16 and 17, except the pressed metal section 1702 provides restraint to double angle members, being held in place by bolts and nuts 1703.

FIGS. 20 to 22 show methods where the triangular truss as in FIG. 1 can have its structural efficiency increased, with respect to non-nodal loads, by offsetting the pivotal hole centres, in members. away from the longitudinal axis. In FIG. 20 the vertical arrows between the node points, represent loads applied to the chords from snow weight or wind loads, applied via purlins, joists, etc. The effect of these non-nodal loads is to produce a bending moment in these chords which must be combined with the axial load in the chord to determine a member size to resist these combined loads. However if the member were curved, as shown in the left hand side of FIG. 20, or bent as shown in the right hand side, the offsetting of the axis of the member from the axis between pivot holes provides an opposite bending moment, generated by the axial loads. This means a reduced sized member can be used to resist the combined loads. In FIG. 21 the same effect is achieved by simply offsetting the holes in the member away from its longitudinal axis. FIG. 22 is similar to FIG. 21, except that a greater offset distance can be achieved by increasing the member depth, by an suitable means, in the vicinity of the pivot holes.

Having seen the beneficial effect of offsetting holes in either single or double members in FIGS. 20 to 22, we can now return to FIGS. 12 and 7, to consider the effect of offsetting separate joining pins, not only away from the member axis but away from each other in both the planar X and Y directions, whereby beneficial opposing forces may be designed to result from the applied loads, to negate or partially negate generated forces, and in particular generated torsional forces as described under FIG. 12.

FIG. 23 is an exploded isometric view of two channel chords 2301 and one square hollow section brace

2302, where it is desired to allow the brace to rotate in relation to the chords, but to prevent rotation between the chords. This selective rigidizing is achieved by using a pin with a keyway 2303 engaged in holes 2304 in the chords, where the holes 2304 are pressed or punched out with an engaging tooth or spline. The hole in the brace is circular and can therefore still rotate around the pin irrespective of the recessed keyway. It can be seen that this principle could be extended to non-selective rigidizing of all members, if all member holes had the tooth or spline, however, non-selective rigidizing could be more easily achieved by using a non-circular pin in non circular holes e.g. a square pin.

FIGS. 24 to 33A show various other node geometries all with advantages and disadvantages over the single pin node shown in FIGS. 1, 2 and 2A. FIGS. 24 to 33A depict various two, three and multiple pin nodes, and in each case diagrammatic elevations are used to show both triangular and parallel chord truss geometries and at least one exploded isometric view of a typical node is shown to illustrate the practicality of the node construction. The nomenclature used in the diagrammatic truss representations is that a circle with no lines continuing through it represents the ends of members and the location of the chord join at the node. Where a circle has a line through it, this represents a hole in a continuous member, and the length of any member is represented by the end of a line at the circumference of a hole.

Now in FIGS. 24 to 25B a two pin node is shown where the chord joins are always separate from the common joining pin for all other braces at that node. FIG. 25A shows a single member truss node depicting node 2401 in FIG. 24 and 2501 in FIG. 25, where angle chords 2510 join at one pivotal pin and angle braces 2511 join to one of the chords and to each other at another pin. FIG. 25B shows the use of double member channel chords 2520 and double member channel braces 2521, together with square hollow section chord 2522 and brace 2523. Other features of the trusses and nodes in FIGS. 24 to 25B are that some of the triangles in the truss have no pivotal discontinuity within their sides, no bending is produced in any member from loads and supports at node points, the non-critical assembly geometry is maintained as in FIGS. 1 and 2, and the trusses and nodes may be further characterized by any features from FIGS. 3 to 23. Also all braces have only one hole at each end and some chords have two holes at one or both ends, and this type of node or truss is referred to as a two pin node or truss.

FIGS. 26 to 27B are similar to FIGS. 24 to 25B, also depicting a two pin node and truss, where the only difference is that some of the braces are permitted to join to the chord to chord pivot join. This alters some features of the trusses and nodes in FIGS. 24 to 25B in that bending is introduced into some chords from nodal loads and some of the internal sub- divisional brace geometry becomes 4 or 5 sides polygons. FIG. 27A shows a single member node where angle chords 2710 and angles braces 2711 represent a node at node 2601 in FIG. 26 and 2701 in FIG. 27. FIG. 27B shows the use of double member angle chords 2720 and double angle braces 2721 in conjunction with square hollow section chord 2722 and brace 2723, where FIG. 27B represents node 2602 in FIG. 26.

FIGS. 28 to 29B are similar to FIGS. 24 to 25B except that one extra hole is provided at the node for brace connections, so that the node or truss becomes a three pin node or truss, with no braces being permitted to connect to the chord to chord join. As the trusses and nodes in FIGS. 26 to 27B had some different features to the trusses and nodes in FIGS. 24 to 25B, so too, the trusses and nodes in FIGS. 28 to 29B also have these feature variations from FIGS. 24 to 25B, being the creation of bending in some members and the creation of some 4 or 5 sided polygons in the internal brace subdivision. FIG. 29A shows a single member node using channel chords 2910 and channel braces2911 representing node 2801 in FIG. 28. FIG. 29B shows double member channel chords 2920 used with square hollow section chord 2921, and braces 2922, with this node being a mirror image of node 2802 in FIG. 28 and 2901 in FIG. 29. Also in FIG. 29 it should be noted that all braces do not join separately to the chord as shown in node 2902 and that the chord join may occur between the brace joins as in node 2903. This three pin node is characterized in that all braces preferably have only one hole at each end and some chords have three holes at one or both ends, and can be further characterized by any of the features depicted in FIGS. 3 to 23. FIGS. 30 to 31A are similar to FIGS. 28 to 29B except that extra holes are provided in the chords so that all braces have a separate joining point to the chord. FIG. 31A is a representation of node 3101 in FIG. 31. This type of node is known as a multiple pin node. FIGS. 32 to 32A show three pin or multiple pin nodes as in FIGS. 28 to 29B or FIGS. 30 to 31A, where at least one brace is connected at the same pin as the chord to chord join. FIG. 33A is representative of the node 3301 in FIG. 33 and it should be noted that the chord to chord join can be between the brace to chord joins as shown in node 3302.

Of course any combination of node types, either single, double, three or multiple pin nodes can be used in a truss which has a suitable geometry for this. FIGS. 34 to 37 show various means of allowing the braces to cross at least one over the other, as they internally subdivide the space within the perimeter of the truss, in such a fashion that the non- critical length assembly feature is maintained. FIGS. 34 and 35 are diagrammatic representations of single pin trusses where the braces could be allowed to pass one by the other by offsetting the braces as shown in FIG. 12. FIG. 36 shows a three pin truss using single chords 3601, double chords 3602, single braces 3603 and double braces 3604. FIG. 37 shows a two pin truss using single member chords 3701, double member chords 3702, and single member half chord width braces 3703, where longitudinal slots 3704 in the braces may be used to secure them to each other. This type of truss shown in FIGS. 34 to 37 is referred to as a "cross over" truss and has significant benefits in terms of reduced deflections when compared to the truss geometry shown in FIGS. 1, 2 and 24 to 33, which means where deflection is the design criteria for the truss, smaller sized members could be used in a "cross over" truss for a specified deflection.

FIGS. 38 and 39 show diagrammatic representations of single pin trusses where one or both ends of some of the braces do not connect to the perimeter chords. Of course this principle could be applied to single members, double members and one, two, three or multiple pin nodes for all chord to chord, brace to chord and brace to brace nodes. FIGS. 40 to 42 show trusses where part of the brace becomes part of the perimeter of the truss. In

FIG. 40 and 41 the same nomenclature for holes and continuous members is used as in FIGS. 24 to 33 from which it can be seen that the braces have more than one hole at some ends and the chords have only one hole at each end. FIG. 42 shows a double channel brace 4201 used with square hollow section chords 4202 and brace 4203. This type of truss has the advantage that the braces which are vertical or near vertical in a truss are of a shorter length and therefore better able to resist the bending moments applied by the chords.

FIG. 43 shows a truss geometry where every alternate chord has a plurality of holes at each end, arranged in a planar geometry such that all member axes intersect at one point, such that bending moments are not generated, however it may prove unnecessary that the intersection point be also on the axis of the chords with the plurality of holes, and it may also be prudent that some of the members have offset holes as shown in FIGS. 21 and 22.

FIG. 44 is a variation on FIG. 43 which allows that cleat plates can be attached to the ends of each alternate chord or one end of each chord such that the pivotal connection holes can be outside the depth limits of the chords in order to achieve one intersection point for all members.

FIGS. 45 and 46 show a truss geometry which uses braces which are wide enough to have a plurality of holes at each end, where the holes are geometrically arranged that all member axes intersect at one point, such that bending moments are not developed in any member. FIG. 46 shows double channel braces 4601 used in conjunction with square hollow section chords 4602 and brace 4603 where FIG. 46 is representative of the node 4501 in FIG. 45. All chords and braces other than the vertical braces shown only require one hole at each end.

FIGS. 47 to 48 show various means of achieving the desired results of FIGS. 45 and 46 where a wider brace provides a common point of intersection of member axes. FIG. 47 shows cleats rigidly fixed to each end of the brace where the cleats are wider than the brace which allows pivotal holes to be provided outside the width extremities of the vertical brace. FIG. 48 shows one method of rigidly fixing the cleat plates by using two bolts or pins in the cleats 4801 and vertical square section brace 4802, where only one pin is then required to pivotally connect the square hollow section chords 4803 and brace 4804. This type of node is particularly suited to all members being of the one size and type, which can be effective in cost economies. FIG. 48A shows that -the cleat plates 4801 can be folded down at the top to facilitate the connection of auxiliary bracing 4805 and also to provide extra planar rigidity across the node. FIG. 48A is an end elevation of FIG. 48. FIG. 48B is an exploded isometric view of alternative cleat plates consisting of double channels 4810, which are double bolted for rigidity to vertical brace 4811. Chords 4812 and brace 4813 only require one hole each end. In FIG. 48B the offset connection of brace 4813 causes bending in brace 4811.

FIGS. 49 and 50 shows a truss where some of the braces are inclined or bent at their ends, with the inclined end section containing the pivotal holes for connection of the chords and other braces, where these braces are designed to resist any bending moments induced by the other member loads. FIG. 50 shows double channel braces 5001 with inclined end sections used in conjunction with square hollow section chords 5002 and brace 5003, where FIG. 50 is representative of nodes 4901 in FIG. 49.

FIG. 51 is similar to FIG. 50, except that the inclined end section is provided by cleat plates 5101, welded to the brace 5102 where chords 5103 and brace 5104 only require one pivotal hole to complete the node. FIG. 52 shows a truss where the chord members are continuous through the node, as shown by the double lines for the top chord. The chords can be joined to prevent rotation between them as shown in FIG. 23 or by bolting or welding individual sections together. In FIG. 52 all brace connections and the bottom chord connections are all single pin pivotal connections, however the use of continuous or rigid joints in the top chord means that all members are now required to be exactly the designed length to allow assembly without forcing members. The geometry in FIG. 52 is referred to as critical length geometry and in view of a required close hole to pin diameter tolerance for this invention, is an undesirable feature. FIGS. 53 and 54 show a method of overcoming the critical length geometry in FIG. 52, where the bottom chord members are adjustable in length before assembly to allow a non-forced assembly, or after assembly to introduce a beneficial prestress into some or all members. In FIGS. 53 and 54 members other than the bottom chords can also be adjustable in length and all members including the members adjustable in length are capable of carrying both compression and tension loads. Whilst single pin joints are shown in FIGS. 52 to 54 any arrangement of single, double, three or multiple pins and single or double members can be used.

FIGS. 55 to 57 show trusses which include some members, which because of their sectional shape are only capable of carrying tensile force e.g. a circular rod. In FIG. 55 the members shown as being adjustable in length signified by the turnbuckle symbol are able to cross one over the other and adjustment of their length after assembly provides a stable triangulated geometry, where some of the adjustable brace rods do not have load in them depending on the direction of the loads at the nodes. FIG. 55A is similar to FIG. 55 and FIGS. 55B and 55C show methods of connecting a "tension only" rod to a single pin node. In FIG. 55B a plate 5501 has the rod 5502 welded to it and a hole 5503 in the plate connects to the common pin at the node with the plate having co-planar abutment with other members at the node. A thread 5504 on the end of the rod connects to a turnbuckle body for length adjustment. Alternatively in FIG. 55C a U shaped bracket 5510 has aligned holes 5511 in multiple faces for co-planar abutment with multiple faces of other members and the U bracket has another hole 5512in it base for penetration of the rod 5513, such that a nut 5514 screwed onto a threaded section of the rod can shorten the effective length of the rod and/or apply a prestress force in the rod.

FIGS. 56 and 57 show practical applications of trusses which include adjustable length "tension only" members. In FIG. 56 a continuous square hollow section top chord 5601 is used in conjunction with square hollow section bottom chords 5602, double channel bottom chords 5603, double channel braces 5604 and adjustable length "tension only" rod braces 5605. It can be seen that the top nodes are two pin nodes and the bottom nodes are three pin nodes. FIG. 57 shows a continuous square hollow section top chord 5701 used in conjunction with double channel braces 5702 and

"tension only" bottom chords and U brackets 5703, as in

FIG. 55C. In the trusses shown in FIGS. 55 to 57 and in any other combination of single or double member, or one, two, three or multiple pin nodes in a truss which includes at least an appropriate number of adjustable length "tension only" members, a characteristic feature of these trusses is that they maintain the non-critical length assembly feature and also have the ability to apply beneficial prestressing to all or selected members in the truss.

FIGS. 58 to 59A show how standardized components can be produced, which allow a large range of types and node geometries to be assembled from modular components. FIG. 58 shows a truss assembled from chords which all have three holes in them at both ends and braces which all have one hole in them at both ends. It can be seen from FIG. 58 that 35 some of the holes in the chords are not used to connect braces, however in some locations all three holes are used. The seemingly unnecessary holes in the chords at some nodes is not important when the benefits of producing a standard chord with three holes at both ends, are considered in view of standardized fabrication techniques e.g. a three hole robotic drill. FIG. 58 shows some of the single or double member, one two, three or multiple pin node options available for use with the system as well as adjustable length members and continuous chord members achieved by using two bolts at the chord join.

FIGS. 59 and 59A also show a method producing a wide range of truss and node types from standardized modular components, where all chords and braces have two holes at each end and the nodes are preferably formed using separate cleat plates which are bolted to one or two of the holes in the members. This allows either a pivotal or rigid connection of any member into the node. A range of cleat plates is shown in FIG. 59 where at least one rigid connection between a chord or brace and the cleat plates is required at every node. FIG. 59A is another option for the system where a single internal brace 5901 uses a common hole with external double channel braces 5902. Plates 5903, and chords 5904 are also shown. In FIG. 59 it can be seen that either single or double members may be used and either single or double cleat plates, and one, two, three and multiple pin nodes are all possible within the system. Also as shown in FIG. 59A the^"*option of having some members inside the cleat plates and some members outside is also possible.

FIGS. 60 and 61 show the basic principle of constructing three dimensional frames out of planar trusses depicted and described in FIGS. 1 to 59A. This is achieved by using chord and/or brace members which are common to more than one planar truss in different planes. In FIGS. 60 and 61 common members extend beyond the truss perimeter as shown in nodes 6001 in

FIG. 60 and node 6101 in FIG. 61, and these common members may also have additional holes in members within the truss perimeter for connection of other members of trusses in different planes, as shown in node 6102. The additional holes in the common members whether they be inside or outside the truss perimeter are provided in faces of the common member not in the same plane as the truss. This use of common members to construct three dimensional frames is further depicted in FIGS. 62, 62A, 63 and 63A.

FIGS. 62, 62A and 63 are isometric drawings of three dimensional nodes using common members to construct three dimensional frames. In FIG. 62 a common square hollow section vertical brace 6201, has holes in it at different levels and in faces at 90 ° to each other to receive pins from cleat plates being parts of different trusses, in planes at 90° to each other. The truss made up of cleat plates 6202, 6203 chord members

6204 and 6205 and brace members 6206 and 6207 connect to the common brace member 6201 at a level which makes this truss greater in depth than the truss at 90° to it made up of cleat plates 6208, 6209, 621 and 6211, chords 6212 and 6213 and braces 6214 and 6215- FIG. 62A shows how double channel chord members 6220 for a truss in one plane and double channel chord members 6221 for a truss in a plane at 90° to it can be used in conjunction with a common square hollow section brace 6222. Square hollow section chords 6223 and 6224 and square hollow section braces 6225 and 6226 are also shown.

FIG. 63 shows a node for two single member trusses at 90° to each other using all members as angles, including the common member 6301.

FIG. 63A illustrates a three dimensional frame using common chord and brace members where the frame is made up of a number of trusses, all at different plane angles to horizontal and vertical reference planes. FIG. 63A is basically an elongated 4 sided pyramid made up primarily of angles which have their faces inclined to each other at angles greater than 90°. The trusses forming the long faces of the pyramid use angle chords 6310, angle braces 6311 and a common angle chord 6312. The trusses on the short face, which are triangles, use braces 6311 common to the long face trusses and pyramid base members 6313, which are also common to a base truss made up of chords 6310 and braces 6313, where the base truss needs extra tension rod bracing for stability. The base truss braces 6313 may be tubular with separate rods carried through them for a rod to chord connection using the vertical face of the chord 6310 to bear against the tube end. Slotted holes 6314 in the vertical faces of the chords 6310 will assist with non- critical assembly of this frame and support posts 6315 (typical) can be used to elevate the frame.

FIG. 64 shows a method of using tubular spacers 6401 similar to that in FIG. 13 except that they are long enough to span between two laterally separated trusses, such that a box truss is formed, which can be stabilized using any convenient form of bracing. The tubular spacers 6401 sleeve over a rod which has a threaded section 6402 at each end which can be joined to the typical joints, B, C and D to form the box truss. In joint B, which is a single member single pin node a bracket 6403 is used to attach bracing and the node is assembled along axis 6404 with the rod and tubular spacer on this axis. In joint C the axis of assembly is along the centre connecting hole for a single member three pin joint as shown. Joint D shows that the box truss could be assembled using common angle brace 6405 and channels across the box to replace the spacer and rod. Bracing of the assembled box truss can be achieved by fixing roof sheeting 6406 on a diagonal angle as shown.

FIGS. 65 and 66 show nodes, where trusses are assembled from alternate single and double member chords. In FIG. 65 double channel chords 6501 alternate with single member square hollow section chord 6502, which join to each other on a separate pivotal pin. To enable the node to be a two pin node which has no bending in its members, the braces 6503 are rectangular hollow section, being half the width of the square hollow section chord 6502, so that both braces may be assembled in a laterally separated position between the channel chords using one pivotal pin. FIG. 13 is similar to FIG. 65 in that the brace members are positioned between double channel chords, except that FIG. 13 is a three pin node with each brace being the same width as the chord.

FIG. 66 is similar to FIG. 65 except that double Z sections 6601, alternate with single chord 6602, and where part of the flanges of the Z's need removal to allow pivotal rotation. FIG. 66 is also a two pin joint where one single brace member 6603 is assembled between the double chords and the other brace consists of double angles 6604 assembled external to the Z section chord, both braces being on one axis, where the chords are pivotally joined to each other on the other axis.

FIG. 67 shows a node from a truss which uses different sized square or rectangular hollow section for all members of the truss, where it is possible to use a single pin node by removing parts of some faces of the members in the vicinity of the pivotal hole. In FIG. 67 one chord 6701 sleeves inside another chord 6702 and both of the chords have sections removed to allow brace 6703 to be assembled inside chord 6701 and brace 6704 is assembled inside brace 6703, such that pivotal rotation can occur between all members.

FIGS. 68 to 70 show how the length of double chord or brace members can be reduced so that they are only long enough to provide a convenient node construction means, and are then reduced to a single more cost effective member for the remaining length between nodes. In other words FIGS. 68 to 70 show convenient means of transforming a single brace or chord member into a double member over a short length, by rigidly attaching short aligned single members, thereby forming a double member for . the convenience of node construction. In FIG. 68 the short double channel chord 6801 is rigidly attached to the single chord 6802 by two bolts 6803. Chord 6804 and braces 6805 may then be joined between the double channels using separate pins. It can be seen that the double channel chord 6801 acts as a double member extension of the single member chord 6802.

FIG. 69 shows the use of cleat plates acting as a double member extension of single member chords and braces, and also shows the use of packer plates to achieve correct co-planar alignment between members. In FIG. 69 cleat plates 6901 and 6902 are double member extensions of single member chords 6903 and 6904 respectively, where two bolts or welding of the cleat plates to the chords forms a rigid connection. These cleat plates also pivotally join to chords 6905 and 6906 and to common brace member 6907. Similarly cleat plates 6908 and 6909 are double member extensions of single brace 6910 and 6911 respectively, 25 where packer plates 6912 and 6913 allow, for example, the correct co-planar alignment of cleat plate 6908 outside cleat plate 6901.

FIG. 70 shows the use of cleat plates 7001 rigidly fixed to the inside faces of brace 7002, where the cleat plates act as double member extensions of the brace 7002, being also different from FIGS. 68 and 69 in that the double member extension is also on a different axis or axes to the single member which it extends. The position of the cleats 7001 in FIG. 70 allows connection of single member chord 7003 and single/double member brace unit 7004 at the same pivot hole without the use of packer plates.

FIG. 71 shows the use of prefabricated heads for single pin pivotal attachment or double pin rigid attachment to other members, where the heads A and B consist of double channels with smaller depth cleats passing through and fixed to them. In the top node in

FIG. 70 the head A is deep enough to allow geometric spacing of the holes in the channels and cleats, such that the axes of the chords 7101 and braces 7102 connecting to the head all intersect at one point which eliminates bending in the members. Note that vertical brace 7103 is attached to the head preferably using 4 bolts for rigid attachment in both truss directions.

Head type B shown at the lower node is a single level head where all chords 7110 and braces 7111 15 enter the head on one level, where the attachment of the braces away from the centre of the head will cause bending in some members and where the single pin join of the brace 7103 to the head for each truss means that the rigidity of the truss in one direction relies on the multiple plane pin attachment in the other truss direction.

FIGS. 72 to 89 now show how the planar trusses and three dimensional frames described in FIGS. 1 to 71 are used to construct structures and building frames, where the methods of obtaining the objects of significant time and cost savings claimed by this invention are shown to be both novel and practical.

FIG. 72 shows a method of using two parallel chord trusses 7201 joined to at least two triangular trusses 7202 to provide a building framework, preferably for a roof, where purlins 7203 are connected to the top chords of the triangular trusses, at 90° to them, and where profiled metal roof sheeting 7204 or tiles are fixed to the purlins to span the distance between the purlins. The roof structure can be assembled at ground level and then lifted and attached to support columns 7205. From FIG. 72 it can be seen that any vertical loads from say wind or snow applied to the roof sheeting will be transferred by the purlins first to the triangular trusses, which transfer their loads to the two parallel chord trusses, which in turn transfer their loads to ground level via the support columns. Any horizontal loads are resisted by the diaphragm action of the roof sheeting or any other form of horizontal bracing fixed between the trusses, which is transferred to the support columns and back to ground level. The columns are preferably designed as free standing cantilevers, so that no bracing is needed below the level of the bottom chords of the trusses. From FIG. 72 it can also be seen that the frame assembly concept is quite different from the more usual and more logical portal frame layout. If the frame layout as shown 15in FIG. 72 were of an industrial shed 40 metres long (longitudinal truss 7201 length) and 20 metres wide (lateral truss 7202 width) it would be normal and seemingly more logical to support each lateral truss 7202 by a column at its ends and eliminate the longitudinal trusses. This would mean the trusses span 20 metres instead of 40 and purlins would span 8 metres between trusses 7202. On the face of it this certainly seems the logical structural layout, however, it has been found by completing many analysis that the structural framework in FIG. 72 is more cost efficient provided the length of the structure is not more than 2.5 times the width.

The reasons for this are as follows: (i) The lateral trusses are much more efficient when supported at their 1/4 span or at calculated positions such that the cantilever section acts to reduce member loads;

(ii) There are only four columns compared to ten in the portal frame system where the savings in (i) and (ii) above are more than enough to cover the cost of the two longitudinal trusses, especially when on ground assembly is included.

It is obvious from FIG. 72 that all frame members have not been included to achieve total stability e.g. lateral bracing of the longitudinal trusses has not been shown. This may be achieved by using a longitudinal wind truss or the diaphragm action of the roof sheeting. As an indication of practical sizes for this four column structure it has been found that additional longitudinal trusses are desirable when the width of the lateral trusses is over 50 metres and that the limit of practicality for the length of the longitudinal trusses is 80 metres. On the lower end of the scale a house size of 7 or 8 metres wide by 10 to 16 metres long is very suited to this particular geometry. Obviously then a vast number of types of buildings are suited to this frame geometry and the support columns being limited to four offers enormous unhindered free space in buildings up to 4000 square metres or one acre in size. FIG. 73 is identical to FIG. 72, except that it has ceiling joists 7301 attached to the underside of the bottom chords of the triangular trusses and ceiling sheeting or planks 7302 attached to these joists, where the ceiling sheeting or planks provide a diaphragm action for the whole structure. From FIGS. 72 and 73 it can be seen that if the ceiling sheeting were designed as a floor the space between the triangular trusses, ceiling and roof sheeting could be used as second storey attic living space. FIG. 74 shows a method of using profiled metal ceiling sheet, suitable to also provide a fixing means for relocatable walls. In FIG. 74 profiled metal roof sheeting 7401 is fixed to the bottom chord of roof framework trusses 7402 via holes 7403 in the roof sheeting and holes 7404 in the truss bottom chord using bolts or rivets (not shown). The profiled metal roof sheeting is supplied in long relatively narrow sheets which lap each other as shown at 7405, to provide a continuous area of ribbed ceiling sheeting, each sheet being joined to each other via the holes 7403 at the laps using rivets or screws (not shown). Now to attach the walls three different methods are shown, the first using channel sections 7406 attached to the roof sheeting via holes 7407 in them aligning with holes 7403 in the ceiling sheeting in conjunction with rivets, screws or bolts (not shown), where the walls 7407 are simply inserted into the channels to gain lateral but not vertical support form the channels. The second method of using the profiled metal roof sheeting to attach the walls is shown where walls 7408 have protruding rods 7409 which are inserted into the holes 7403 in the ceiling, to form a vertical slip joint in which the wall gains only lateral support form the ceiling sheeting. The third method of using the ceiling sheeting to support the walls is shown using wall panel 7410 which has holes 7411 recessed into it, and securing pins 7412 pass through the holes 7403 in the ceiling and into the holes 7411 in the panel, again forming a vertical slip joint. Also shown in FIG. 74 is a section 7413 which can be fixed over the metal ceiling profile and holes 7403 to provide air conditioning registers. A magnetic ceiling tile 7414 is also shown which can be attached to the profiled metal ceiling for improved aesthetics and to allow different ceilings in different rooms, especially when walls are relocated to vary room sizes and locations.

FIG. 75 shows how the roof structure is constructed to be independent of the floor, walls and furniture, and how services may be carried inside the column supports for reticulation from the roof space to the rooms below. In FIG. 75, the columns 7501 support the roof structure 7502, where this cross sectional elevation in FIG. 75 can also be related to FIG. 72 and

73 and column service ducts 7503 are run inside the columns. Also shown in FIG. 75 is the ground floor slab

7504, which it can be seen is totally independent from the column and roof structure. Also shown are three different types of wall panels 7505, 7506 and 7507, where wall panel 7505 is secured in place by having pins or protruding rods extending from it which are inserted into holes in the ceiling as per wall panel 7408 in FIG. 74 and into holes in the floor slab. Wall panel 7506 is fixed to the ceiling and floor using channel sections as shown for wall panels 7407 in FIG. 74 where the panel may be inserted from a side position into the channels or the top channel may be deeper than the bottom channel which allows the panel to be positioned with an upwards and drop motion, which will still provide a slip joint at the ceiling level, or alternatively two angle skirting board sections may secure the panel at floor level. Wall panel 7507 is different in principle to the other two panels, in that it is hung from the roof structure and has a slip joint arrangement at the floor level. Also shown in FIG. 75 is a mobile cupboard 7508 which can also be used as a wall. A system of drains 7509 is shown below the floor slab with risers 7510 extending to floor level, however it should also be noted that underground drains can be eliminated by using small macerator pumps and small discharge lines, located above floor level, which can be supplied and installed as a total wall, fixture and discharge pump unit, prefabricated in a factory situation.

Now that the independent nature of the roof, floor walls, and furniture has been shown with the aid of FIG. 75, it is necessary to return to FIG. 73 to explain the construction sequence, where it can be seen that the floor columns are outside the plan area of the total roof and that the roof can be completed at or near ground level including all sheeting, gutters, facias, vents, insulation, linings, gable ends, skylights, services and attic room construction, prior to lifting and fixing to the support columns. From FIG. 73 it can be seen that it is preferred to support the roof on only four columns, one at each end of the parallel chord trusses, and also it can be seen that having erected the roof as the first phase of the construction sequence, other work such as floor slab, walls and services can be carried out with the roof protection from sun, rain, snow, etc. which will significantly reduce construction times.

From FIGS. 73 and 75 it can also be seen that not only is the system suitable for concurrent factory fabrication of walls, but also suits the factory fabrication of total rooms, particularly wet area rooms which could be delivered onto the site and slid sideways into place between the ceiling and floor, and it can also be seen that these prefabricated rooms may or may not be supplied with a ceiling or floor. One significant feature of using prefabricated walls and/or rooms not immediately apparent from FIGS. 73 and 75 is that economies in design are available because of the independent nature of the roof, floor and walls i.e. the floor does not support the walls which^' are in turn required to support the roof.

FIG. 76 shows a roof framework constructed using more than two parallel chord trusses 7601 and more than two triangular trusses 7602, where columns 7603 used for lifting and support are shown and a column or prop 7604 which is installed after lifting is also shown, where any number of columns or props 7604 can be installed under the plan area of the roof after lifting.

FIG. 77 shows one method of installing temporary lifting equipment on the columns. The columns 7701, have a temporary gantry 7702 attached to a top plate on the column, where the temporary gantry is made up of two channels attached to a rotating plate 7703, which has a centre pin 7705 attached to it and protruding downwards, and the gantry also has a rigid top plate 7704 attached to a circular pipe body, where the plates 7703 and 7704 rotate one over the other. The gantry also has radial fins 7707 attached to the body and an adjustable length arm 7706 for different arm locations on the channels. The gantry has attached to it a chain block 7708, operated by a man 7709, which lifts the roof or floor unit 7710. The column may be extendable in length using plates bolted together, accessible by hand holes 7711 in the column. A safety chain 7712 is also supplied to prevent wind uplift of the roof or floor during lifting or at delays during lifting.

FIGS. 78 to 81 shows a method of casting and erecting walls under the erected roof structure by using a casting bed 7801, which has two semi-circular wheels 7802 attached to it underside, supported by spokes 7803 and two jockey wheels 7804 engageable with the floor. The cast concrete panel 7805 or assembled brick panel 7805 is cast or assembled on the bed 7801 and when cured can be rotated through 90° to a vertical position with the aid of handles 7806. From FIGS. 79 to 81 it can be seen that the centre of gravity of the panel remains directly above the point of contact between the semi-circular wheels and the ground, and therefore the force required to rotate the panel will be minimal.

FIG. 82 shows a method of constructing a combined floor/ceiling unit for use in a multi-story building as shown in FIG. 83. In FIG. 82 the floor/ceiling unit is constructed using any number of parallel chord trusses in one direction, intersected by any number of parallel chord trusses at preferably 90° to them, such that four perimeter trusses determine the length, width and depth of the frame. In FIG. 82 one of these truss 8201, supports profiled metal ceiling sections 8202, which in turn support decorative ceiling tiles 8203 which may be magnetic for attachment to the ceiling. A pressed ridge in one side of the ceiling section aligned and inserted into a pressed recess in an adjacent section as shown at 8204 will prevent misalignment of surface levels between sections. Also shown in FIG. 82 are five different types of roll formed metal floor panels, 8205 to 8209. Floor panel unit 8205 has a pressed ridge 8210 on one side and a pressed matching recess 8211 on the other side, which, when engaged prevent uneven deflections in the floor between panels. Aligned holes 8212 in the panels 8205 also provide a means for bolting to ensure a more positive interlock. Floor panel 8206 also has holes 8213 for bolting to adjacent panels and has longitudinal ribs 8214 pressed into the panel, which provide additional strength, particularly if the unit is filled with a cementitious material. Floor panel 8207 also has aligned holes for panel to panel bolting and a downwardly returned lip 8216, which strengthens the edge of the section and allows moisture drainage. Alternatively the edge lip may be turned up provided holes 8218 are provided for moisture drainage. Panel 8208 is shown filled with concrete or similar and has steel reinforcing mesh 8219 to strengthen the panel. Floor panel 8209 combines the best features of all the panels i.e. pressed ribs, edge interlocking means turned down lips, and reinforcing mesh, as well as a shape which is efficient in the use of concrete or other filling material. A floor sheeting 8220 is also shown. In FIG. 82 with all the floor panels it should be noted that they may be filled in an inverse position with concrete or similar and turned over after curing, where the concrete provides fire, acoustic and insulation protection. Other features of the floor/ceiling unit as shown in FIG. 82 are that preferably the unit is deep enough to contain all services and deep enough to provide a crawl space for serviceman to repair or relocate services, and the unit is braced horizontally by the floor and ceiling sheeting and is lined externally over the perimeter trusses to form a completely enclosed unit.

FIGS. 83 and 84 to 89 show a multi storey building construction, a method of construction and a construction sequence. In FIG. 83, four column supports 8301 are erected first in the sequence, and the roof structure consisting of two parallel chord trusses 8302 and a number of triangular trusses 8303, as shown in FIGS. 72 or 73 is assembled inside the plan area of the columns. Floor/ceiling units 8304 as described under FIG. 82 are also located inside the plan area of the floor columns. In FIG. 83, all services are located inside the four column supports for reticulation to rooms through the roof and floor/ceiling space. Since the columns are designed as free standing cantilevers, no bracing is required between ceiling and floor levels, and therefore prefabricated walls and/or rooms may be installed between floor and ceiling as shown in FIG. 75.

FIGS. 84 to 89 show the sequence of erection of the structure where the roof 8401 is assembled on the ground between the columns 8402, which are free standing cantilever extensions of bored piers 8403.

In FIG. 85 the roof is raised and fixed in its final location and in FIG. 86 the first floor/ceiling unit is assembled and raised as in fig 87. In FIG. 88 the second floor/ceiling unit is assembled and raised as shown in FIG. 89.

Various changes and modifications may be made to the embodiments described and illustrated without departing from the scope of the invention defined in the appended claims.

Claims

1. A planar truss or frame, assembled from a plurality of straight elongate structural members, and capable of carrying both axial tension and compression each member having a longitudinal axis with a pivotal joining hole near both ends of each member, the holes being parallel to each other and at or near 90° to the longitudinal axis and located on the axis, the members being subdivided into two basic components termed chords or braces; where the chords are defined as those members pivotally attached one to the next via circular pins through the holes, to form a closed polygon being the perimeter of the truss or frame; and the braces are also connected via the holes in their ends to the pins connecting the chords, such that the braces subdivide the internal planar space within the perimeter into a number of triangles to stabilise the truss or frame, and further characterised by the braces not crossing one over the other; whereby the two dimensional geometry of the truss or frame is not dependent for assembly upon critical tolerances in length between hole centres in the members, due to circular pins used in the holes to connect the members, which allows pivotal rotation between all members in the plane of the truss or frame, where this type of joint arrangement is referred to as a single pin node.

2. A truss or frame as claimed in Claim 1, wherein: the members are of such a cross sectional shape, as to provide at least one face parallel to the members longitudinal axis and at 90° to the holes at its ends, for co-planar contact between members, where the ends of the members are cut at any predetermined angle to prevent any integral parts of the members when joined, from bearing against each other and preventing rotation between the members about the common joining pin, where such cross sectional shapes include but are not limited to channels, lipped channels, equal angles, unequal angles, Z sections, lipped Z sections and I beams.

3. A truss or frame as claimed in Claim 1, wherein: the cross sectional shape of the members in the vicinity of the holes is reshaped or flattened to provide a surface area parallel to the member axis for co-planar contact with adjacent members, the area of the surface provided for co-planar contact being of a size which allows rotation of the members relative to each other, about their common joining pin, in the plane of the member axis and in the plane of the truss or frame.

4. A truss or frame as claimed in any one of Claims 1 to 3 wherein: the ratio of the diameter of the holes in the members, to the diameter of the pin, is less than 1.01.

5. A truss or frame as claimed in any one of Claims 1 to 3 wherein: each pin is tapered in diameter over its length such that the pin when joining a number of members, all with the same sized holes, can be inserted into the holes, so that the clearances of the pin in one member is zero and the clearance in adjacent members is dependent on the taper of the pin, and in any member, the ratio of the diameter of the hole to the diameter of pin is less than 1.005.

6. A truss or frame as claimed in Claim 2 or Claim 3 wherein: the pins, used to join the members via the holes in the members, also include means to clamp the co-planar faces of the members together with a controlled amount of force such that rotation between all members is still possible, whilst the clamping action maintains a degree of structural integrity or continuance between members in planes parallel to the axis of the pin, such clamping action also being referred to as lateral structural rigidity through or across the join, and where the clamping action is provided by a threaded section and nut on each end of the pin.

7. A truss or frame as claimed in Claim 6 wherein: lateral structural continuance or rigidity across the member joins is achieved by some members having at least two planar faces for abutment with each other member, in conjunction with a single pin through aligned holes in each face at the ends of the members, where the clamping action of the pin may not be required, and where the members include square hollow section, rectangular hollow section, circular hollow section, channels and lipped channels.

8. A truss or frame as claimed in Claim 6 or Claim 7 wherein: some of the members have only one planar face and some of the members have two or more planar faces.

9. A truss or frame as claimed in Claim 8 wherein: at least one member with two planar faces is replaced by two separate members with identical relative location and geometry, but separated laterally at 90° to the plane of the truss and its members, with both members being pivotally connected to at least two other similar members; or at least one other single member with two co-planar faces; and to each other, by a common pin.

10. A truss or frame as claimed in Claim 9 wherein: the separated members in identical relative location and geometry, are connected to each other by any suitable means, at, at least one location between the end connection holes, where the connection means allows the joined members to function structurally as a combined member, with load carrying properties in excess of the summation of the individual properties of both members.

11. A truss or frame as claimed in any one of Claims 7 to 10 wherein: members with more than one planer face are connected to other members with a separate pin for each face, where the pins are on one axis.

12. A truss or frame as claimed in any one of Claims 1 to 11 wherein: the members are bent or curved in the plane of the truss or frame, such that an eccentricity is produced between the axis of the member and the axis connecting the holes in the member, where the amount of eccentricity is designed such that the bending moment produced by axial loads in the members equals to the bending movement produced by planar loads applied to the members between the pivot pins.

13. A truss or frame as claimed in Claims 1 to 12 wherein: an eccentricity is designed into any member by offsetting the hole centres from the member axis to produce an opposing bending moment.

14. A truss or frame as claimed in Claims 1 to 12 wherein: separate cleat plates are rigidly fixed to the ends of members, such that holes in the cleat plates for one or more faces can be provided outside the line of the extremities of the members to produce a greater eccentricity than by offsetting the whole centres.

15. A truss or frame as claimed in Claims 1 to 12 wherein: an eccentricity between the member axis and the line joining the pivot holes in the member is produced by any combination of methods as set out in Claims 12, 13 and 14.

16. A truss or frame as claimed in Claim 11 wherein: the separate pins are not on the same axis such that eccentricities may be produced in members not only in the plane of the truss or frame but also in other planes to counter other force which may be generated by lateral offsetting of members away from each other.

17. A truss or frame as claimed in any one of Claims 1 to 16 wherein: the pins and holes in selected members, have an engaging recessed key ways in the pin and raised splines in the holes to provide a rigid or fixed connection means between selected members, whilst not interfering with a pivotal connection between each pin with a recessed key way and a member with a circular hole.

18. A truss or frame as claimed in any one of Claims 1 to 16 wherein: non-circular holes in members and matching non circular pin allows non-selective rigidizing of all members with respect to each other at joints between the members.

19. A truss or frame as claimed in any one of Claims 1 to 18 wherein: at least some of the chord members have two holes in close proximity at, at least one end, so that the braces with one hole at each end, provide stable triangulation within the chord perimeter, when pivotally connected to the holes furtherest from the ends of the chords, such that the chord join pivots, only connect one chord to an adjacent chord and have no braces attached at that join; where at least some of the triangles framed by the braces and the chords have no pivotal chord joins within their perimeter; and this type of joint arrangement is referred to as a double pin node, where bending in the plane of the tress or frame is not introduced into the members by virtue of the geometry.

20. A truss or frame as claimed in Claim 19 wherein: at least one of the braces joins to the chord at the same location as the chord join, which is the pivotal hole closest to the end of the chord, such that the internal sub-division within the perimeter consists of at least some four sided polygons as well as triangles, where this type of join arrangement is also referred to as a two pin node.

21. A truss or frame as claimed in Claim 19 wherein: at least some of the chord members have three holes in close proximity at, at least one end, where all braces connect to the chords at other than the chord-to-chord pivotal join, where at least some of the braces and chords form four sided polygons as part of the internally sub-divided geometry within the perimeter, and this type of joint arrangement is referred to as a three pin node.

22. A truss or frame as claimed in Claim 19 wherein: at least some of the chord members have more than three holes in close proximity at, at least one end, where all braces connect to the chord at holes not being the end chord join hole, and where no more than one brace pivotally joins a chord where any other brace pivotally joins a chord, and all chord-to-chord joins are separate to chord-to-brace joins, where the joint arrangement is known as a multiple pin node.

23. A truss or frame as in Claims 21 or 22 wherein: at least one of the braces connects to the chord at a chord to chord join.

24. A truss or frame as in Claims 1, or 19 to 23 wherein: any combination of one, two, three or multiple pin nodes are used.

25. A truss or frame as claimed in any one of Claims 1, or 19 to 24 wherein: the braces are laterally separated and allowed to cross at least one over one other, within the perimeter of the truss or frame.

26. A truss or frame as claimed in Claim 25 wherein: the braces are connected to each other at the point of cross over, by either a pin joint, a rigid joint, or a joint using a circular pin in a slotted longitudinal hole in each member.

27. A truss or frame as claimed in any one of Claims 1 to 24 wherein: at least one brace end joins to at least one other brace end within the perimeter of chords, and not to the chord.

28. A planar truss or frame as claimed in any one of Claims 1, or 19 to 24 wherein: at least one of the braces has at least two holes at one or both ends, on its member axis; and chords and/or braces are pivotally connected via pins to these holes in the braces, such that one or more of the parts of the brace between the holes at its end or ends becomes part of the perimeter of the truss or frame.

29. A planar truss or frame as claimed in any one of Claims 1, or 19 to 24 wherein: the perimeter is made up of chords in which every alternative chord has a plurality of holes at each end for pivotal connection of other chords and braces, which have only one hole at each end, and where the geometrical arrangement of the plurality of holes in the alternate chords is such that all member axes intersect at the one point, so that members will not develop bending moments due to axial loads, or the geometrical arrangement may be such that a designed beneficial eccentricity can be introduced into any chord or brace.

30. A truss or frame as claimed in Claim 29 wherei : cleat plates are rigidly fixed to both ends of each alternate chord or one end of each chord, the cleat plates being of a larger depth than the chord, so that the pivotal joining holes in the cleat plates can be spaced further apart than within the chords themselves.

31. A planar truss or frame as claimed in any one of Claims 1 or 19 to 24 wherein: some of the brace members have a plurality of holes at one or both ends, for pivotal connection of other brace members and/or chord members which have one hole at each end, and where the geometrical arrangement of the plurality of holes at the end or ends of these braces is such that all member axes intersect at one point, so that members will not develop bending moments due to axial loads, or the geometrical arrangement may be such that a designed beneficial eccentricity can be introduced into any chord or brace.

32. A truss or frame as claimed in Claim 31 wherein: cleat plates are rigidly fixed to the ends of some of the braces, the cleat plates being of a larger width than the braces, so that the pivotal joining holes in the cleat plates can be spaced further apart than within the braces themselves.

33. A planar truss or frame as claimed in any one of Claims 1 or 19 to 24 wherein: some of the chords or braces are bent or change direction at their ends, such that end sections, inclined to the main section of the chord or brace, contain a plurality of holes for connection of the remaining chords and braces, and the inclined end sections of the braces or chords form part of the perimeter of the truss or frame

34. A truss or frame as claimed in Claim 33 wherein: each inclined end section consists of cleat plates rigidly fixed to the brace or chord.

35. A planar truss or frame as claimed in any one of Claims 1 to 34 wherein: at least two chords are joined rigidly to each other at the node, or are continuous through the node, and all brace connections are pivotal at those nodes.

36. A planar truss or frame as claimed in any one of Claims 1 to 35 wherein: at least one of the braces and/or chords, capable of carrying either axial compression or axial tension forces, is adjustable in length either before or after assembly of the frame.

37. A planar truss or frame as claimed in any one of Claims 1 to 35 wherein: at least one of the braces and/or chord members, because of its cross sectional shape and area, is only capable of carrying practical tensile axial forces, and where these members may or may not be adjustable in length either before or after assembly of the frame.

38. A planar truss or frame as claimed in any one of Claims 1, or 19 to 24 wherein: all chords have three holes at each end and all braces have one hole at each end, which allows standardised production of members suitable for assembly of a large range of standardised trusses or frames, including all one, two and three pin nodes.

39. A planar truss or frame as claimed in any one of Claims 1, or 19 to 24 wherein: all chords have two holes at each end, and all braces have two holes at each end, which allows standardised production of members, suitable for assembly of a large range of standardised trusses or frames, including all one, two and three pin nodes, where cleat plates are needed to be fixed to the ends of any or all braces and/or chords, where two of the holes at the ends of the braces or chords are used for non- pivotal, rigid fixing of the cleat plates to the member.

40. A planar truss or frame as claimed in any one of Claims 1 to 39 wherein: at least one chord and/or brace extends or protrudes beyond the continuous perimeter of the chords, and this extension or protrusion of the member has holes in it, at 90° to other faces of the member, to allow pivotal connection of other members in different planes to that truss or frame.

41. A three dimensional frame made up of any number of intersecting planar trusses or frames as claimed in any one of Claims 1 to 39 wherein: extensions or protrusions of members beyond the perimeter and/or additional holes in at least two faces of one brace and/or chord allows the use of common members to form a three dimensional frame structure.

42. A planar truss or frame as claimed in any one of Claims 1 to 40, or a three dimensional frame as claimed in Claim 41, wherein: the node or joint construction is further characterised by the use of tubular tube spacer sleeves fitting over the pins and located between at least two faces on single or double members, such that the clamping method incorporated on the pin causes these faces to bear against the end of the tubular sleeve, thereby providing a lateral restraint for the face to prevent lateral buckling of the face due to forces in the plane of the member face.

43. A three dimensional frame incorporating two or more planar trusses or frames as claimed in Claim 42 wherein: the tubular sleeve spacers are located between two laterally separated planar trusses, each truss being preferably of single members, where the tubular sleeves and the pins located in them, are sufficiently long to allow the two planar trusses and joining pins or rods, to function as a box truss, especially when laterally braced any convenient means in the plane of the pins and sleeves.

44. A planar truss or frame as claimed in any one of Claims 1 to 40, 42, or three dimensional frame as claimed in Claim 41 or Claim 43 wherein: the chords consist of alternate single and double members; where the single members are square or rectangular hollow sections; and the double members are either angles, channels or Z sections; and further characterised in that the braces are pivotally connected between the double members, and where the braces are half the width of the single members and two braces are laterally spaced and fixed with one pin between the double members.

45. A planar truss or frame, or a three dimensional frame, as claimed in any one of Claims 1 to 44 wherein: the chords and/or braces are single members formed from square or rectangular hollow section, of varying sizes, such that removal of parts of the non- planar faces near the pivotal holes in the planar faces, allows the planar faces to fit inside or outside of adjacent member planar faces, where the removal of that section of the non-planar face also allows pivotal rotation between members joined on common pins.

46. A planar truss or frame, or three dimensional frame, as claimed in any one of Claims 1 to 45 wherein: single chords or braces, of square- or rectangular hollow section have cleat plates attached to faces in one or more planar truss directions where the cleat plates become separate single plate members at the pivoted hole or joint location, and the fixing method of the cleats to the members is by two bolts, or welding, and where aligned cleat plates act as a structural two member extension of the single member, and the cleat plates are fixed to the square- or rectangular hollow section on either the inside or outside faces of the section, and the use of packer plates will allow the lateral separation of the cleat plates to be increased for co-planar attachment to other members, or other cleat plates attached to other members, and where the aligned holes in the cleat plates are on the single member axis, or offset to produce beneficial eccentricities.

47. A planar truss or frame, or three dimensional frame as claimed in Claim 46 wherein: the cleat plates are fabricated as joined together units, called heads or nodes, for attachment during assembly, to the braces or chords, using two pins for a rigid joint and one pin for a pivotal connection, and where the cleat plate head or node is designed for truss chords or braces entering the head at one or more levels, and any variation of horizontal or vertical truss plane, and where the cleat plates are sized such that some cleat plates are wider than others, which allows one set of cleats to pass through another set for single level entry of all chords at the head or node, and in particular, where the cleat plates are different sized channel sections which allows the flanges to be rigidly fixed to each other for greater strength.

48. A three dimensional frame as claimed in any one of Claims 1 to 47, consisting of: two vertical planar parallel chord trusses assembled in a laterally separated parallel relationship with each other and joined to at least two vertical planar triangular trusses which cantilever beyond them, where the triangular trusses have fixed to them, a number of purlins on the top chords, where these purlins have profiled metal roof sheeting or tiles fixed to them such that the planar trusses resist any vertical load, and horizontal loads are resisted by very convenient form of bracing, fixed between the trusses, and by the diaphragm action of the roof sheeting or tiles, and where the internal space bounded by the roof sheeting or tiles and planar trusses is su ficient to be usable as living space, in addition to the sheltered space below this three dimensional frame when it is elevated and used as a roof structure.

49. A three dimensional roof structure frame as claimed in Claim 48 wherein: ceiling battens or joists are attached to the underside of the bottom chords of the triangular trusses, and a profiled metal ceiling is fixed to them, such that the metal ceiling forms a structural diaphragm for the roof and is suitable for the attachment of decorative magnetic or other ceiling tiles.

50. A three dimensional roof structure frame is claimed in Claim 48 or Claim 49 wherein: the whole roof structure is assembled at or close to ground level, including all gutters, facias, rents, insulation, lining, gable ends, skylights and devices and attic room construction, prior to lifting by any convenient means and fixing to supports, where the supports consist of four columns external to the plan area of the roof, each column being adjacent to an end of the two parallel chord trusses, and where services such as drainage, water, power, gas and telecommunication cables are run inside the columns to roof space for reticulation to the space below.

51. A roof structure as claimed on any one of Claims 48 to 50 wherein: more than two parallel chord trusses and more than four support columns are used.

52. A roof structure as claimed in any one of Claims 48 to 51 wherein: some or all of the support columns are also used for attachment of temporary lifting means, such as chain blocks, wire winches, pulley wheel assemblies, electric or pneumatic hoists, or any other lifting means, and where support columns not used for lifting may be installed after the roof is lifted, especially where these columns are not external to the plan area of the roof.

53. A building structure, which includes a roof structure as claimed in any one of Claims 48 to 52 wherein: a concrete floor slab is constructed, under the roof structure, after the roof structure has been assembled on the ground and lifted into place, where the ground floor slab is totally independent of the column supports for the roof and does not support the roof in any way.

54. A building as claimed in Claim 53 wherein: prefabricated lightweight, non load bearing, relocatable walls are used to span between the roof or ceiling to the floor, to enclose and secure space within the building, where the floor provides vertical and horizontal support to the walls, and where the roof or ceiling provides only horizontal or lateral support, using any convenient vertical slip joint arrangement, all the walls being non-load bearing, and where the walls are prefabricated to contain all services and fixture units for reticulation from the roof space, so that no services are required underground the slab within the building area, which allows easy relocation of walls and services.

55. A building as claimed in Claim 54 wherein: at least some of the walls are supported both vertically and horizontally at the roof or ceiling level, and only laterally at the floor line using any form of slip joint arrangement, such that these lightweight walls hang from the roof structure, and are foldable up into a horizontal or near horizontal position to open up internal space, or provide extra roof cover around the perimeter of the building.

56. A building as claimed in any one of Claims 48 to 53 wherein: prefabricated rooms are installed between the roof or ceiling and floor, where the walls of the rooms are braced one against the other, such that the room only require vertical support at the floor, and where the rooms, particularly wet area rooms are completely finished prior to site delivery, such that connection of all services in the roof space ensure a reduced construction time for the building and a convenient means of relocating rooms if desired.

57. A building as claimed in Claim 56, using prefabricated rooms, wherein: the rooms are delivered as individual walls, for fixing together on site to assemble the room, and where a separate floor and separate ceiling may or may not be part of the room.

58. A building structure as claimed in any one of Claims 48 to 53 wherein: walls are cast on casting beds under the erected roof structure, where the casting beds have at least two semi-circular supports under them for tilting the cast wall from a horizontal casting position into a vertical operational position, where these semi-circular supports are designed are and fixed to the casting bed such that the centre of gravity of the cast wall is directly above, or nearly above the point of contact of the semi-circular supports with the floor, and where the casting bed also has smaller disengageable wheels for manoeuvering the casting bed into a position, such that tilting it through from horizontal to vertical will place the wall in its required location.

59. A building structure, for a house or residential building, as claimed in any one of Claims 1 to 58, erected by a construction sequence wherein: the roof is first constructed on the ground, and after the roof erection, installation of ground floor slab will allow prefabricated walls and services to be installed under the roof and where the use of prefabricated walls and furniture allows concurrent construction thereof.

62. A three dimensional frame as claimed in any one of Claims 1 to 47 wherein: any number of planar parallel chord trusses laterally spaced apart, in one direction are intersected by and joined to any number of planar parallel chord trusses laterally spaced about in another direction, usually at 90° to each other, where the trusses are assembled at or near ground level and have floor sheeting or tiles fixed to their top chords and ceiling sheeting fixed to their bottom chords, and have services installed between these, and the perimeter trusses are lined such that a completely enclosed floor/ceiling unit has been constructed, with the unit being horizontally braced by the floor and ceiling sheeting, where the floor and/or ceiling sheeting is fire resistant and the space within the unit is large enough for a workman to crawl into and relocate the services, and the unit is assembled inside the plan location of four or more column supports, for lifting and fixing part way up the column supports, thereby providing a relatively lightweight floor/ceiling unit for use in multi-level buildings.

61. A multi-level building structure using a roof frame as claimed in Claims 1 to 52, walls as claimed in any one of Claims 54 to 58, and floor ceiling units as claimed in Claim 60 wherein: the sequence of construction is to first assemble and erect the roof structure, then each floor ceiling unit in turn, prior to installing the prefabricated, relocatable walls and/or rooms, and where the columns supports are also service ducts.