WO2013088154A1

WO2013088154A1 - New building blocks, building systems and methods of building

Info

Publication number: WO2013088154A1
Application number: PCT/GB2012/053123
Authority: WO
Inventors: Hamad HUSAIN
Original assignee: Intelligent Building Processes Ltd
Priority date: 2011-12-13
Filing date: 2012-12-13
Publication date: 2013-06-20
Also published as: GB2497537A; GB2497537B; GB201121347D0

Abstract

A building system comprising a plurality of blocks (10) and interlocking members (80), each block (10) comprising: a core (12); a groove (20) in the core (12) for receiving, in use, an interlocking member (80), the or each interlocking member (80) comprising: a first potion partially receivable, in use, in a groove (20) of a first block (10); and a second portion projecting beyond a surface of the core (12) of the first block (10), said second portion being receivable in a groove (20) of a second block (10) located adjacent the first block (10), wherein the interlocking members (80) are adapted to have an interference fit with the grooves (20) of the blocks (10) so as to lock, in use, adjacent blocks (10) to one another, and wherein the groove (20) of each block (10) extends around at least two sides of the core (12) and is accurately located relative to the core (12) to provide a datum for aligning adjacent blocks (10).

Description

NEW BUILDING BLOCKS, BUILDING SYSTEMS AND METHODS OF BUILDING

Description: This invention relates to new types of building blocks, building systems, and methods of building. It also relates to methods of manufacturing building blocks and buildings constructed using the same.

Buildings can be fabricated in a variety of ways. One of the most traditional methods involves building wall structures by laying individual bricks on top of each other and by holding them in place using mortar. Furthermore, to meet modern building standards, brick-built structures often need to comprise inner and outer walls separated by a cavity that is filled with a thermally insulative material. Brick-built structures generally last a long time but can be expensive and time- consuming to construct.

To speed-up the building process, many builders nowadays prefer partial or complete prefabrication, which involves building panels or part-completed elements off-site that can be assembled on-site to form the building. Prefabrication offers a number of advantages, including being less weather-sensitive, and affording some scope for pre-finishing and pre-installation of utilities, such as pipe work and electrical circuits. As such, prefabricated buildings can be erected more quickly, and often more cheaply, than traditional brick-built structures, but they still require a considerable amount of planning and off-site construction before they can be assembled.

More recently, hybrid modular building systems, such as Insulated Concrete Form (or "ICF") have been devised that enable the skeleton of a structure to be assembled on-site in a manner that permits a reasonable amount of ad-hoc modification, whilst reducing overall construction time. An example of such a modular building system comprises a number of hollow polystyrene blocks that can be fitted together to form the skeleton or outline of and building, but, which when assembled, can be in-filled with poured concrete to form the final structure. Such a system has considerable advantages over traditional brick built structures and wholly prefabricated buildings owing to the ability for the builders to cut and/or modify the blocks on-site. However, poured concrete is a relatively expensive material and is considered to be environmentally unfriendly. Moreover, owing to the flexibility of the polystyrene skeleton, there is some scope for movement of the polystyrene blocks during the concrete pouring process, which can give rise to inaccuracies in the final construction. In addition, although the completed system is structurally sound, the exterior and interior facades of the building require a considerable amount of finishing if the polystyrene is not to be left exposed. The fact that the existing polystyrene block system has inherent inaccuracy and because it requires such a large amount of finishing means that the material cost and time savings gained by using such systems can easily be outweighed by the additional labour time and cost of the finishing and fitting operations.

A need therefore arises for a building system that overcomes one or more of the above problems, whilst still affording flexibility in terms of design and on-site modification.

According to a first aspect of the invention, there is provided a pre-finished building block comprising: a core; a groove in the core for receiving, in use, an interlocking member for locking the block to another like block located adjacent thereto, wherein the groove extends around at least two sides of the core and is accurately located relative to the core to provide a datum for aligning adjacent blocks.

According to a second aspect of the invention, there is provided a building system comprising a plurality of blocks and interlocking members, each block comprising: a core; a groove in the core for receiving, in use, an interlocking member, the or each interlocking member comprising: a first potion partially receivable, in use, in a groove of a first block; and a second portion projecting beyond a surface of the core of the first block, said second portion being receivable in a groove of a second block located adjacent the first block, wherein the interlocking members are adapted to have an interference fit with the grooves of the blocks so as to lock, in use, adjacent blocks to one another, and wherein the groove of each block extends around at least two sides of the core and is accurately located relative to the core to provide a datum for aligning adjacent blocks.

The building block or system of the invention may further comprise a first fascia affixed to a first side of the core, a second fascia affixed to a second side of the core, the first and second sides are located on opposite sides of the core.

The outer surface of a first one of the fascias preferably comprises a finished exterior surface of or for a building and the outer surface of a second one of the fascias preferably comprises a finished interior surface of or for a building.

The invention differs from known building blocks, such as bricks, inasmuch as the facades are pre-finished, that is, they do not require a substantial amount of post-construction finishing to complete the build. This is achieved by the provision of an accurately positioned groove, which serves as a reference datum for the build and into which an interlocking member is receivable. By accurately positioning the groove with respect to, or by making the groove, a reference datum for the build, when the interlocking members are used, adjacent blocks automatically align with one another.

In addition, the peripheries of the fascias are preferably formed to provide, in use, an accurate edge-to-edge fit with the periphery of an adjacent block. This can be achieved by machining the fascias' peripheries to provide, in use, an accurate edge-to-edge fit with the periphery of an adjacent block. The peripheries or edges of the fascias can be formed to any desired pattern, although flat edges are generally preferable as they enable the accuracy of the fitting of blocks atop one another to be largely independent of the relative position of underlying or overlying courses of blocks. In a preferred embodiment of the invention, the edges or peripheries of the fascias are formed such that, in use, the gap between adjacent edges of adjacent blocks is less than 1mm, more preferably less than 0.5mm, and most preferably less than 0.1 mm.

The outer surfaces of the fascias are pre-finished, and can have a flat, rough or textured surface finish depending on the aesthetic requirements of the build.

The core of the blocks can be manufactured from a foam material, such as an expanded polystyrene foam, which is lightweight, relatively strong and stiff, and which has excellent thermal and acoustic insulation properties. The core of the blocks may be hollow or solid. Suitably, the core of the blocks could be manufactured from a blow-moulded or injection-moulded plastics material, preferably hollow to improve the blocks' thermal, acoustic properties and/or to make them more lightweight. A solid core could additionally or alternatively be manufactured from wood, glass, plastics, concrete, and metal. It may also be possible to use blocks made from various combinations of materials at different locations, for example, an integrally formed glazing block manufactured from glass, acrylic or polycarbonate surrounded by blocks made, or finished in other materials. Decorative blocks, such as blocks manufactured or finished with a metal surface may also be integrated into the design of a building.

Hollow blocks may be useful where the wall is non-structural (e.g. a fence, boundary or partition wall) or temporary (e.g. moveable dividers in an open-plan office space) as they can be made relatively lightweight. For example, a matching hollow block manufactured from blow- moulded polystyrene, polypropylene or recycled plastics may be used to create an interesting feature or to provide a lightweight exterior structure. It will be apparent that there a great many permutations and combinations of hollow or solid cored blocks manufactured from, or finished in, different materials, that could be used in a single build. This affords an architect or designer a great deal of design freedom when designing buildings. Nevertheless, because the blocks all have the alignment/registration grooves, it is a relatively straightforward matter to substitute different types of blocks at different locations.

The core can additionally comprise cut-outs, which can further lighten the structure. By providing cut-outs in the core that are arranged to overlap/intersect cut-outs of adjacent blocks, it is possible to in-fill the continuous or semi-continuous cavities formed thereby with poured concrete, insulation material or any other desired in-fill material. In addition, the provision of continuous cavities permits conduits, pipes or trunking to be installed within the structure either off-site or during the building process. Moreover, cavities enable reinforcing bars (e.g. "rebar") or other structural elements, such as reinforcement beams, joists, lintels and the like, to be integrated in the structure.

The fascias, where provided, are preferably manufactured from a castable material, such as concrete, ceramic or a stone-filled polymer composite. The range of castable materials, also referred to herein as liquid curable materials, can be mixed or blended to have a wide range of colours, textures and surface finishes. A liquid curable material, in the context of the invention, however, is one that can be poured into a mould in a liquid state, but which can be caused to set or cure to form a hard, rigid, substantially hard or substantially rigid material. When, say, a concrete infill is used, the concrete sets to form a hidden, reticulated sub-structure within the wall.

The core preferably comprises one or more keying formations for retaining the cast material. In other words, the keying formations help the liquid curable material to key, or affix, to a surface of the core.

According to a third aspect of the invention, there is provided a method of manufacturing a pre-finished building block comprising the steps of: forming a core; forming a reference groove in at least two surfaces of the core; positioning the core in a mould by aligning the reference groove with respect to a datum; at least partially filling a first space between a first exterior surface of the core and a first interior surface of the mould with a liquid curable material; at least partially filling a second space between a second exterior surface, opposite the first exterior surface, of the core and a second interior surface of the mould with a liquid curable material; curing the liquid curable material to form a building block comprising first and second fascias affixed to opposite sides of the core; removing the building block from the mould; and machining the edges of the fascias such that their peripheries provide, in use, an accurate edge-to-edge fit with the periphery of a like adjacent block.

It will be appreciated that the method of manufacturing a pre-finished building block differs from conventional methods inasmuch as a laminated (fascia-core-fascia) structure is formed, and inasmuch as the visible surfaces and edges of the blocks are pre-finished.

To assist the affixing of the fascias to the core, the method preferably further comprises the step of, prior to at least partially filling the first or second spaces with a liquid curable material, forming keying formations in a surface of the core to which a fascia will be affixed. The keying formations preferably comprise an undercut portion, such as one or more grooves comprising a substantially dovetail cross-section. The grooves are preferably arcuate and are most preferably provided as a number of sets of arcs, each set being centred on spaced-apart centres.

As previously described, it can sometimes be advantageous to remove a portion of the core to form, in use, continuous or semi-continuous cavities within a wall formed of a plurality of blocks. The core material removed to form the continuous or semi-continuous cavities can, if desired, be reused or recycled.

Buildings can, of course, be manufactured from the building blocks described herein. To do this, a building could be designed in a CAD system and the blocks for that building made to order. In such a situation, each block will be identifiable by a code that corresponds to a particular block within the CAD model. As such, on-site assembly is then a matter of setting out the blocks according to their individual positions in the CAD model. To simplify the design and assembly process, a range of standardised block shapes, configurations and sizes may be provided. For example, a two-sided block may be used in most situations, i.e. having a generally cuboid core located between finished planar interior and exterior surfaces (fascias) of desired specifications. Corner blocks may also be provided, in which the core is formed as an L-shaped prism, and whereby the interior and exterior fascias are applied to two surfaces each. Similarly, lintel and sill blocks, adapted to be positioned, respectively, above and below doorways and windows, may comprise substantially cuboid cores with fascias applied to three surfaces thereof to conceal the core in the "reveal" of the door or window aperture. A range of straight, cubic, cuboid, curved, etc. blocks of different sizes could be provided in in the CAD model, which correspond to different mould set-ups for making the blocks in question. Such a system affords the architect a great deal of design freedom, whilst still enabling the building as a whole, to be modular and easily transportable from factory to construction site.

In the same way that there may inevitably be a range of blocks, so too may there by a range of interlocking members, e.g. straight connectors, X-connectors, L-connectors, offset-X-connectors, etc. to enable the blocks to be positioned relative to one another in a variety of ways.

Preferred embodiments of the invention shall now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a perspective view of a first type of building block according to the invention;

Figure 2 is a schematic cross-section of Figure 1 on ll-ll;

Figure 3 is a schematic cross-section of a pair of blocks shown in Figures 1 and 2 stacked on top of each other

Figure 4 is a perspective view of a first type of building block according to the invention; Figure 5 is a perspective view of a second type of building block according to the invention; Figure 6 is a perspective view of a third type of building block according to the invention; Figure 7 is sequence showing a manufacturing process for the blocks;

Figure 8 is a perspective view of a straight interconnecting element for the invention;

Figure 9 is a perspective view of hanger-type interconnecting element for the invention; Figure 10 is a perspective view of an L-join type interconnecting element for the invention; Figure 11 is a perspective view of an T-join type interconnecting element for the invention;

Figures 12 and 13 are perspective views of the interconnecting elements of Figures 8 to 11 fitted together in various configurations;

Figure 14 is a plan view of the straight interconnecting element of Figure 8; and

Figures 15 and 16 are T and X-type blocks similar to those show in Figures 4, 5 and 6 for forming wall junctions;

In Figure 1, a building block 10 is formed from a central polystyrene core 12 and an outer skin 14 manufactured from cast concrete or another castable material. The building block 10 is generally cuboid and can be fitted edge to edge with other identical or similar blocks (not shown). The central core 12 is cut from a solid block of expanded polystyrene foam and has a hollowed-out central portion that can optionally be in-filled with poured concrete or any other suitable material. As can be seen best in Figure 2 the central core 12 as a generally H-shaped cross-section formed by upright plate portions 16 that are integrally formed with cross members 18 and maintain the upright plate portions 16 in a parallel and spaced apart relationship to one another. The upright plate portions 16 have a groove 20 formed therein that provides a datum or reference for aligning adjacent blocks 10 with respect to one another. Because the grooves 20 serve as a datum or reference for the build, they are accurately machined to ensure that their spacing 22, depth 24 and vertical separation 26 are exactly the same from one block 10 to the next. By using the grooves 20 as a reference, the other dimensions of the block 10 do not necessarily need to match in order for the blocks to fit together. Nevertheless, if a smooth and continuous interface between adjacent blocks is required then the spacing 28 of the grooves 20 with respect to the outer surfaces 30 of the blocks 10 should be constant. This accuracy can be achieved by virtue of the manufacturing process for the blocks, which is described in detail below.

Turning now to Figure 3, it will be noted that the blocks 10 can be fitted together using press-fit interlocking elements 32 that seat snugly in the grooves 20 of adjacent blocks 10. The peripheries (in the example shown, the upper and lower surfaces 34) of the upright plate portions 16 and outer skins 14 are machined flat to provide intimate face-to-face abutment between the polystyrene cores 12 and fascias 14 of adjacent blocks 10, thereby inhibiting penetration of the elements and cold air between adjacent blocks. It will also be apparent that an invisible join between adjacent blocks can be formed if the surfaces 34 are sufficiently flat. In use, a bead of sealant, or adhesive, may be applied to one of the surfaces 34 to provide an airtight and watertight seal between adjacent blocks 10.

It will be noted that the interconnecting elements 32 are completely surrounded by the polystyrene core 12, therefore preventing thermal bridging across, or between, the blocks 10. In addition, by positioning the blocks as shown in Figure 3, a continuous or semi-continuous cavity 36 can be formed between the upright plate portions 16, which can be filled with poured concrete or any other suitable cavity-filling material.

In the embodiment of the invention shown in Figures 1 to 3, each block has a pair of outer skins 14 located on opposite sides of the core 12, which form the visible exterior and interior facades of the building. The outer skins 14 are therefore manufactured from specified materials to give a desired colour, texture, flatness and reflectivity etc. In addition, due to the manufacturing process, which will be described in greater detail below, it is possible to manufacture the outer skins from different materials such that the building, as erected, is "pre-finished".

A plurality of blocks 10 as shown in Figures 1 to 3 can be positioned end-to-end and stacked on top of each other to form a continuous flat wall structure. To form a corner, however, a corner- type block needs to be used such as that shown in Figure 4.

In Figure 4, a corner-type building block 50 is shown having a generally L-shaped central core 12 when viewed from above. The construction of the corner block 50 is substantially the same as that of the straight block 10 shown in Figures 1 to 3. Accordingly, identical reference signs have been used to identify identical features. In order to fit together with other similar blocks in the system, the dimensions 22, 24, 26 and 28 of the corner block 50 need to exactly match those of the blocks in the system. Even though the corner block 50 has a generally L-shaped profile when viewed from above, it will be appreciated that its construction is substantially the same as that of a straight block 10 inasmuch as it comprises a central foam core 12 and an outer skin 14 formed on opposite sides of the central core 12.

A further variation of the straight block 10 is an end block 52 as shown in Figure 5. Again, identical reference signs have been used to identify identical features in the drawings. The main difference between the end block 52 and the straight 10 or corner blocks 50 is provision of an additional outer skin portion 54 that extends over the end of the block 52, spanning the outer skins 14 to conceal the central core 12 from view.

A yet further variation of the straight block 10 is a sill or lintel block 56 as shown in Figure 6. Again, identical reference signs have been used to identify identical features in the drawings. The main difference between the sill or lintel block 56 and the end block 52 is provision of an additional outer skin portion 58 that extends underneath or over the block 56, spanning the outer skins 14 to conceal the central core 12 from view from above or below. Such a block 56 can be used above a doorway or window aperture to conceal the core 12 in the reveal.

The blocks 10 are manufactured by a novel process, as illustrated, schematically, in the series of drawings of Figure 7. The blocks 10 are manufactured by cutting a solid block of expanded polystyrene foam, which will form the core of the block 10, into a cuboid, as shown in Figure 7a. Thereafter, dovetail profile grooves 60 are machined into the faces of the core 12 to provide a keying surface for the liquid curable fascias that are applied later. It will be seen that the dovetail profile grooves 60 are cut on arcs centred on different points to provide a pattern of grooves 60 resembling overlapping "gothic arches". Although other groove patterns could be adopted, it has been found that this particular arrangement of grooves 60 improves the flow of poured liquid curable material, thereby reducing the incidence of cavities or voids in the set material.

Next, as shown in Figure 7c, the registration grooves 20 are accurately machined into the upper, lower and end faces of the core 12 using a special jig to ensure that they are accurately spaced-apart. The locations of the registration grooves is critical, as they provide a datum not only for the remaining manufacturing process, but also for the eventual building process.

In Figure 7d, the prepared core 12 is located within a mould 64, which is formed from a pair of spaced-apart glass panels 66. The glass panels 66 are specially manufactured to have an extremely flat surface, and the flat side of the glass 68 faces inwards towards the foam core 12. The glass panels 66 are retained at an exact spacing by spacer bars 70, which have abutment surfaces (not visible) that mate with the inner surfaces 68 of the glass panels 66, which have been accurately machined, to within a few microns, to ensure that the spacing of the glass panels 66 is accurate to within a few microns. The spacer bars 70 also carry discs 72 whose positions correspond, exactly, to those of the registration grooves 20 of the foam core 12. The prepared foam core 12 can thus be accurately located within the mould ready for the next stage of the process, which involves filling the space between the core 12 and the glass panels 66, with a liquid curable material 74.

As previously described, the liquid curable material can be selected to give a desired appearance, structural, functional, thermal and acoustic properties, depending on the application. However, because of the flatness of the glass panels, a flat or mirror-like finish is easily obtainable. Nevertheless, the glass panels 66 could be replaced with textured panels to give a textured finish is certain situations.

Once the liquid curable material has set, the block 10 can be removed from the mould, as shown in Figure 7e, and any excess material 76 machined back to the level of the underlying foam core 12, as shown in Figure 7f. Finally, the foam core 12 can be hollowed-out, if desired, to produce a building block such as that shown in Figure 1.

Of course, different mould setups may be used to produce corner, end or lintel blocks. One of the key features of the manufacturing process is the spacer bars 70, which determine the outer dimensions of the blocks, and which ensure that the registration grooves 20 of the foam cores 12 are exactly spaced relative to the outer surfaces of each block. Even the slightest inaccuracy in this respect could cause the core 12 to misaligned with respect to the fascias 14, which may prevent the blocks from fitting together in the final build. Moreover, a misalignment of even a few microns, when extrapolated along a wall of several metres in length, could create significant inaccuracies in the overall build. As such, the correct registration of the core 12 with respect to the glass panels 66 is a crucial step in the manufacturing process.

As described above in relation to Figure 3, the blocks can be fitted together and interconnected using interconnecting elements. The interconnecting elements comprise a system of profiled bars and connectors that can be fitted together to form a framework that is concealed within the blocks.

The interconnecting element system comprises four main components, namely: a straight bar interconnector, as shown in Figure 8; a hanger-type interconnector, as shown in Figure 9; an L- join interconnector, as shown in Figure 10; and a T-join interconnector, as shown in Figure 11.

In Figure 8 it will be seen that the straight bar interconnector 80 comprises an elongate metal extrusion having a generally J-shaped cross-section. The straight bar interconnector 80 is formed from a strip of metal that is folded to have a tall upright portion 82 and a short upright portion 84 that are connected at their lower ends to a cross member portion 86. The bottom of the "J" seats in the upper registration groove 20 of a block 10, and the upper edge of the tall upright 82 engages with the lower registration groove of a block 10 located above it. A straight bar interconnector 80, can therefore be used to connect adjacent courses of blocks 10 to one another.

To interconnect a pair of blocks 10 end-to-end, the straight bar interconnector 80 can be reoriented vertically such that it engages the end registration grooves 20 of adjacent blocks 10. However, where a horizontal and vertical straight bar interconnector 80 meet, one of three joint pieces can be used.

The first type of joint piece is shown in Figure 9, which is a hanger-type piece 88 for joining the top end of a vertical straight bar 80 to the underside of a horizontal straight bar 80, as shown in Figure 12. The hanger-type joint piece 88 comprises a generally planar main body portion 90 having an inverted J cross section portion 92, which is essentially an inverted version of the cross-section of the straight bar interconnector 80. The inverted "J" portion 92 can hook over the tall upright of 82 of the straight bar interconnector 80 and hang below it, passing through an aperture (not shown) in the cross member portion 86. Projecting transversely from one side of the main body portion 90 of the hanger-type join piece 88, is a rectangular tab 94 that engages the interior face of the short upright portion 84 of the straight bar interconnector 80.

The next type of join piece, as shown in Figure 10, is an L-join interconnector 96, which too has a main body portion 98, which is formed from a pair of integrally formed, swan-neck cross- section pieces 100 arranged at right angles to one another. Both swan-neck portions 100 share a common, generally L-shaped central spine plate 102, which has, projecting from one surface, a pair of rectangular tabs 104 which are arranged at right angles to one another. The rectangular tabs 104 engage the interior of straight bar interconnectors 80 in the same manner as the rectangular tabs 94 of the hanger-type interconnector 88 previously described. Projecting outwardly from the opposite side of the central spine plate 102 are a pair of J-cross-section elements, which functions in the same way as the J-section portion 92 of the hanger-type join piece 88, described above. The L-join interconnector, 96 can be used for joining the bottom end of a vertical straight bar 80 to the top of a horizontal straight bar 80, as shown in Figure 12.

The T-join interconnector 106, as shown in Figure 11, is similar to the L-join interconnector 96 previously described, except for the addition of a vertically downwardly extending extension piece 108 and a further rectangular tab 104 extending from it at right angles, which engages the interior of a straight bar interconnectors 80 at a level below a horizontal straight bar interconnector 80. The T-join interconnector 106 can be used for joining a pair of intersecting straight bars 80 at right angles, as shown in Figure 13.

It will also be noted, from Figure 13, that strips of expanded polystyrene foam or other insulating material 85 can be inserted into any open spaces in the interconnector structure. Conveniently, expanded polystyrene foam is readily deformable and can be squashed into spaces of differing widths by compression. Whilst the polystyrene strips 85 have no structural role per se, they can be used to help lock intersecting bars together by friction and can be added to improve the thermal properties of the overall structure.

It will also be noted in Figure 13, that the bars have through holes 87 that align when the structure is assembled. The through holes 87 enable screws, rivets or other mechanical fasteners 89 to be used, if necessary, or specified in the building's design, to lock intersecting interconnecting bars together.

In Figure 14, it will be noted that the straight interconnecting member 80 comprises L- shaped through apertures at spaced apart locations. The purpose of the L-shaped apertures is to enable vertical bars and connectors to pass through the cross member portion 86 thereof. The L- shaped apertures are spaced to correspond to the block intersections, for example, every 200mm, which would enable them to be used in conjunction with blocks whose lengths are integer multiples of the aperture spacings, e.g. 200mm long, 400mm long, 600mm long, etc. Where two or more walls of a building intersect, intersection blocks, such as those shown in Figures 15 and 16 may be required. In Figure 15, a T-shaped block allows one wall to meet another at right angles, whereas the X-shaped block of Figure 16 allows two walls to intersect at right angles. Identical reference signs have been used to identify identical features in the drawings for ease of understanding.

The invention is not restricted to the details of the foregoing embodiments, which are merely exemplary. For example, the shape, dimensions and materials used could be varied without departing from the scope of the invention.

Claims

Claims:

A pre-finished building block comprising: a core; a groove in the core for receiving, in use, an interlocking member for locking the block to another like block located adjacent thereto, wherein

the groove extends around at least two sides of the core and is accurately located relative to the core to provide a datum for aligning adjacent blocks.

A building system comprising a plurality of blocks and interlocking members, each block comprising: a core;

a groove in the core for receiving, in use, an interlocking member, the or each interlocking member comprising:

a first potion partially receivable, in use, in a groove of a first block; and

a second portion projecting beyond a surface of the core of the first block, said second portion being receivable in a groove of a second block located adjacent the first block, wherein the interlocking members are adapted to have an interference fit with the grooves of the blocks so as to lock, in use, adjacent blocks to one another, and wherein

the groove of each block extends around at least two sides of the core and is accurately located relative to the core to provide a datum for aligning adjacent blocks.

A building block or system as claimed in claim 1 or claim 2, further comprising a first fascia affixed to a first side of the core, a second fascia affixed to a second side of the core, the first and second sides are located on opposite sides of the core.

4. A building block or system as claimed in any of claim 1, 2 or 3, wherein the outer surface of a first one of the fascias comprises a finished exterior surface of or for a building.

5. A building block or system as claimed in any of claims 1 to 4, wherein the outer surface of a second one of the fascias comprises a finished interior surface of or for a building.

6. A building block or system as claimed in any preceding claim, wherein the peripheries of the fascias are formed to provide, in use, an accurate edge-to-edge fit with the periphery of an adjacent block.

7. A building block or system as claimed in claim 6, wherein the peripheries of the fascias are machined to provide, in use, an accurate edge-to-edge fit with the periphery of an adjacent block.

8. A building block or system as claimed in claim 7, wherein the edges or peripheries of the fascias are formed such that, in use, the gap between adjacent edges of adjacent blocks is less than lmm, less than 0.5mm, or less than 0.1 mm.

9. A building block or system as claimed in any preceding claim, wherein the outer surfaces of the fascias are pre-finished.

10. A building block or system as claimed in any preceding claim, wherein the core of the blocks is manufactured from a foam material.

11. A building block or system as claimed in claim 10, wherein the foam material comprises expanded polystyrene foam.

12. A building block or system as claimed in any preceding claim, wherein the core of the blocks is hollow.

13. A building block or system as claimed in claim 12, wherein the core is manufactured from a hollow, blow-moulded plastics material.

14. A building block or system as claimed in any preceding claim, wherein the core of the blocks is manufactured from any one or more of the group comprising: wood, glass, plastics, concrete, and metal.

15. A building block or system as claimed in any preceding claim, wherein the core additionally comprises cut-outs.

16. A building block or system as claimed in any preceding claim, wherein the fascias are manufactured from a castable material, or liquid curable material.

17. A building block or system as claimed in any preceding claim, wherein the core comprises one or more keying formations in a surface thereof adjacent a fascia.

18. A building block or system according to any preceding claim, further comprising one or more additional fascias affixed to further surfaces of the core.

19. A building block or system according to any preceding claim, comprising a two-sided block comprising a generally cuboid core located between finished planar interior and exterior fascias.

20. A building block or system according to any preceding claim, comprising a corner block, in which the core is formed as an L-shaped prism, and whereby the interior and exterior fascias are applied to two surfaces each.

21. A building block or system according to any preceding claim, comprising a lintel or sill block comprising a substantially cuboid core with fascias applied to three surfaces thereof.

22. A building system according to any of claims 2 to 21, comprising a plurality of straight, cubic, cuboid, and curved, blocks of different shapes and/or sizes.

23. A building system according to any of claims 2 to 22, further comprising a plurality of interlocking members.

24. A building system according claim 23, wherein the interlocking members comprise any one or more of the group comprising: a straight bar interconnector, a hanger-type interconnector, a T- join interconnectors and an L-join interconnector.

25. A building system according claim 24, wherein the straight bar interconnector 80 comprises an elongate metal extrusion having a generally J-shaped cross-section.

26. A building system according claim 25, wherein the bottom of the "J" is adapted to seat within a groove of a building block according to any of claims 1 to 21.

27. A building system according claim 24, wherein the hanger-type join piece comprises a generally planar main body portion having an inverted J cross section portion adapted to hook over an upright portion of a straight bar interconnector.

28. A building system according claim 24, wherein the L-join interconnector comprises a main body portion formed from a pair of integrally formed, swan-neck cross-section pieces arranged at right angles to one another.

29. A building system according claim 28, wherein swan-neck portions of the L-join interconnector share a common, generally L-shaped central spine plate.

30. A building system according claim 24, wherein the T-join interconnector comprises an L-join interconnector and an extension piece extending from the main body portion.

31. A building system according any of claims 25 to 30, wherein the interconnector element further comprises a tab portion projecting transversely from one side of the main body portion for engaging, in use, the interior of the J of a straight bar interconnector.

32. A building manufactured from a plurality of building blocks or a system according to any preceding claim.

33. A method of manufacturing a pre-finished building block comprising the steps of: forming a core with a reference groove formed in at least two surfaces of the core; positioning the core in a mould by aligning the reference groove with respect to a datum; at least partially filling a first space between a first exterior surface of the core and a first interior surface of the mould with a liquid curable material; at least partially filling a second space between a second exterior surface, opposite the first exterior surface, of the core and a second interior surface of the mould with a liquid curable material; curing the liquid curable material to form a building block comprising first and second fascias affixed to opposite sides of the core; removing the building block from the mould; and machining the edges of the fascias such that their peripheries provide, in use, an accurate edge-to-edge fit with the periphery of a like adjacent block.

34. A method as claimed in claim 33, further comprising the step of, prior to at least partially filling the first or second spaces with a liquid curable material, forming keying formations in a surface of the core to which a fascia will be affixed.

35. A method as claimed in claim 34, wherein the keying formations comprise any one or more of the group comprising: an undercut portion, one or more grooves comprising a substantially dovetail cross-section, one or more arcuate grooves, and a plurality of sets of arcuate grooves, each set being centred on spaced-apart centres.

36. A building block or system substantially as hereinbefore described, with reference to, and as illustrated in the accompanying drawings.

37. A method of manufacturing a building block substantially as hereinbefore described, with reference to, and as illustrated in Figure 7 of the accompanying drawings.