Fitting external insulation systems to buildings

Abstract

There is disclosed a method of retro-fitting an external insulation system to a building, and a retro-fit external insulation system for a building. One disclosed method comprising the steps of: mounting a plurality of support elements (16) to an existing external surface (14) of a wall (12) of a building (10); providing a plurality of surface panels (22), each of which comprises an internal wall-facing surface (36) and an external surface (38); arranging the surface panels so that they cover at least a substantial part of the existing external surface of the wall; mounting each surface panel to one or more of the support elements, so that cavities (40) are defined between the internal wall-facing surfaces of the panels and the existing external surface of the wall; and supplying flowable insulation material (42) into the cavities; in which the step of mounting the support elements to the external surface comprises positioning at least one adjustable one-piece spacer (108) between each support element and the surface, the spacer comprising a first end (112) which abuts the surface and a second end (114) which abuts the support element, and adjusting the spacer to vary a space (110) between the support element and the surface.

Claims

1. A method of retro-fitting an external insulation system to a building, the method comprising the steps of: mounting a plurality of support elements to an existing external surface of a wall of a building; providing a plurality of surface panels, each of which comprises an internal wall-facing surface and an external surface; arranging the surface panels so that they cover at least a substantial part of the existing external surface of the wall; mounting each surface panel to one or more of the support elements, so that cavities are defined between the internal wall-facing surfaces of the panels and the existing external surface of the wall; and supplying flowable insulation material into the cavities; in which the step of mounting the support elements to the external surface of the wall comprises: positioning at least one adjustable one-piece spacer between each support element and the external surface of the wall, the spacer comprising: a first end adapted to abut the external surface of the wall; a second end adapted to abut the support element; a main axis extending in a direction between the first and second ends; a first mounting face which is at a first distance from the first end of the spacer; and a second mounting face which is at a second distance from the first end of the spacer, the second distance being greater than the first distance; adjusting the spacer between a first configuration in which the first mounting face abuts the support element, and a second configuration in which the second mounting face abuts the support element, by rotating the spacer relative to the support element about the main axis, to vary a space between the support element and the external surface of the wall; clamping the adjustable spacer between the support element and the external surface of the wall; and passing a fixing through the support element and the spacer into the wall to clamp the spacer.

2. A method as claimed in claim 1, wherein adjusting the spacer comprises rotating the spacer about a main axis extending in a direction between the first and second ends.

3. A method as claimed in claim 1, further comprising arranging the adjustable spacer so that the spacer provides a substantially uniform distribution of load on the wall, during use.

4. A method as claimed in claim 1, wherein the second end of the spacer comprises a first mounting face which is at a first distance from the first end of the spacer, and a second mounting face which is at a second distance from the first end of the spacer, the second distance being greater than the first distance, and wherein the step of mounting the support elements to the external surface of the wall comprises adjusting the spacer between: a first configuration in which the first mounting face abuts the support element; and a second configuration in which the second mounting face abuts the support element, to thereby adjust the space between the support element and the external surface of the wall.

5. A method as claimed in claim 4, wherein the second end of the spacer comprises at least one further mounting face which is at a further distance from the first end of the spacer, the further distance being greater than the second distance, and wherein the step of mounting the support elements to the external surface of the wall comprises adjusting the spacer into at least one further configuration in which the further mounting face abuts the support element.

6. A method as claimed in claim 4, comprising adjusting the spacer between the first and second configurations by rotating the spacer about a main axis extending in a direction between the first and second ends.

7. A method as claimed in claim 1, comprising closing tops of at least some of the cavities using at least one top barrier member, and arranging said top barrier member so that the top barrier member allows water vapor to escape from the cavities; closing bottoms of at least some of the cavities using at least one bottom barrier member, and arranging said bottom barrier member so that the bottom barrier member allows liquid water to escape from the cavities; and arranging the flowable insulation material so that liquid water in the cavities can pass through the flowable insulation material to said bottom barrier member and so exit the cavities, and so that water vapor in the cavities can pass through the flowable insulation material to said top barrier member and so exit the cavities.

8. A method as claimed in claim 7, wherein the step of supplying flowable insulation material into the cavities comprises supplying a plurality of particles of a solid insulating material into the cavities, and arranging the solid insulation material so that a plurality of channels are defined within the solid insulating material, through which liquid water and water vapor can pass.

9. A method as claimed in claim 7, comprising positioning at least one cover member over said top barrier member, to prevent liquid water from falling on to the barrier member, the at least one cover member defining a lower condensing surface, and the method further comprising arranging said cover member so that the lower condensing surface faces towards an upper surface of the at least one top barrier member, water vapor exiting the cavities condensing on the lower condensing surface.

10. A retro-fit external insulation system for a building, comprising: a plurality of support elements, the support elements being mountable to an existing external surface of a wall of a building; a plurality of surface panels, each of which comprises an internal wall-facing surface and an external surface; and a flowable insulation material; in which the plurality of surface panels are adapted to cover at least a substantial part of the existing external surface of the wall; and in which the surface panels are each adapted to be mounted to one or more of the support elements, so that cavities are defined between the internal wall-facing surfaces of the panels and the existing external surface of the wall, into which the flowable insulation material can be supplied; and in which the system further comprises a plurality of adjustable one-piece spacers, each spacer being adapted to be positioned between a support element and the external surface of the wall, the spacers comprising: a first end adapted to abut the external surface of the wall; a second end adapted to abut the support element; a main axis extending in a direction between the first and second ends; a first mounting face which is at a first distance from the first end of the spacer; and a second mounting face which is at a second distance from the first end of the spacer, the second distance being greater than the first distance; wherein the spacers are each adjustable between a first configuration wherein the first mounting face abuts the support element, and a second configuration wherein the second mounting face abuts the support element, by rotation relative to the support element about the main axis, to vary a space between the support element and the external surface of the wall; and fixings for clamping the adjustable spacers between the support element and the external surface of the wall, each fixing adapted to pass through the support element and one of the spacers into the wall.

11. A system as claimed in claim 10, wherein the adjustable spacers provide a substantially uniform distribution of load on the wall, during use.

12. A system as claimed in claim 10, wherein each of the spacers is of a generally cylindrical tubular shape.

13. A system as claimed in claim 10, wherein the second end of each of the spacers comprises a first mounting face which is at a first distance from the first end of the spacer, and a second mounting face which is at a second distance from the first end of the spacer, the second distance being greater than the first distance, and wherein each of the spacers is adjustable between: a first configuration wherein the first mounting face abuts the support element; and a second configuration wherein the second mounting face abuts the support element, to thereby adjust the space between the support element and the surface.

14. A system as claimed in claim 13, wherein the second end of each spacer comprises at least one further mounting face which is at a further distance from the first end of the spacer, the further distance being greater than the second distance, and wherein each of the spacers is adjustable into at least one further configuration wherein the further mounting face abuts the support element.

15. A system as claimed in claim 13, wherein the first and second mounting faces of each spacer comprises a plurality of mounting face portions which together define the respective mounting face.

16. A system as claimed in claim 13, wherein the first and second mounting faces are spaced around a periphery of the spacer at the second end.

17. A system as claimed in claim 13, wherein each of the spacers is of a generally cylindrical tubular shape, and wherein the first and second mounting faces are spaced around a circumference of the spacer at the second end.

18. A system as claimed in claim 13, wherein the first and second mounting faces are defined by at least one support arranged transverse to a main axis of the spacer.

19. A system as claimed in claim 18, wherein each of the first and second mounting faces is defined by a plurality of supports which together define the respective mounting face.

20. A system as claimed in claim 10, comprising restraints for restraining rotation of each of the spacers relative to the support element.

21. A system as claimed in claim 20, wherein the restraints are arranged to cooperate with lateral sides of the support element.

22. A system as claimed in claim 20, wherein a pair of the restraints cooperate with a mounting face to define a channel for receiving the support element.

23. A system as claimed in claim 10, comprising: at least one top barrier member; and at least one bottom barrier member; in which the at least one top barrier member is adapted to close tops of at least some of the cavities, and to allow water vapor to escape from the cavities; in which the at least one bottom barrier member is adapted to close bottoms of at least some of the cavities, and to allow liquid water to escape from the cavities; and wherein the insulation material is adapted to permit liquid water in the cavities to pass through the material to said bottom barrier member and so exit the cavities, and to permit water vapor in the cavities to pass through the material to said top barrier member and so exit the cavities.

24. A system as claimed in claim 23, wherein said top barrier is adapted to restrict liquid water from entering the cavities, comprising a plurality of apertures sized to permit the passage of water vapor but to restrict the passage of liquid water.

25. A system as claimed in claim 23, comprising at least one cover member which can be positioned over said top barrier member, wherein said cover member defines a lower surface, and is adapted to be arranged so that the lower surface faces towards an upper surface of the at least one top barrier member, the lower surface forming a condensing surface to facilitate condensation of water vapor escaping from the cavities.

26. A system as claimed in claim 10, wherein external surfaces of the panels form a decorative surface finish.

27. A method of retro-fitting an external insulation system to a building, the method comprising the steps of: mounting a plurality of support elements to an existing external surface of a wall of a building; providing a plurality of surface panels, each of which comprises an internal wall-facing surface and an external surface; arranging the surface panels so that they cover at least a substantial part of the existing external surface of the wall; mounting each surface panel to one or more of the support elements, so that cavities are defined between the internal wall-facing surfaces of the panels and the existing external surface of the wall; and supplying flowable insulation material into the cavities; wherein the step of mounting the support elements to the external surface comprises: positioning a spacer between each support element and the external surface of the wall, wherein the spacer is hollow, adjustable and one-piece, the spacer comprising: a first end adapted to abut the external surface of the wall; a second end adapted to abut the support element; a main axis extending in a direction between the first and second ends; a first mounting face which is at a first distance from the first end of the spacer; and a second mounting face which is at a second distance from the first end of the spacer, the second distance being greater than the first distance; and adjusting the spacer between a first configuration wherein the first mounting face abuts the support element, and a second configuration wherein the second mounting face abuts the support element, by rotating the spacer relative to the support element about the main axis, to vary a space between the support element and the external surface of the wall.

28. A retro-fit external insulation system for a building, the system comprising: a plurality of support elements, the support elements being mountable to an existing external surface of a wall of a building; a plurality of surface panels, each of which comprises an internal wall-facing surface and an external surface; and a flowable insulation material; wherein the plurality of surface panels are adapted to cover at least a substantial part of the existing external surface of the wall; wherein the surface panels are each adapted to be mounted to one or more of the support elements, so that cavities are defined between the internal wall-facing surfaces of the panels and the existing external surface of the wall, into which the flowable insulation material can be supplied; and wherein the system further comprises a plurality of spacers, each spacer of the plurality of spacers being hollow, adjustable, one-piece, and adapted to be positioned between a support element and the surface, each spacer of the plurality of spacers comprising: a first end adapted to abut the surface; a second end adapted to abut the support element; a main axis extending in a direction between the first and second ends; a first mounting face which is at a first distance from the first end of the spacer; and a second mounting face which is at a second distance from the first end of the spacer, the second distance being greater than the first distance; in which each spacer of the plurality of spacers is adjustable between a first configuration in which the first mounting face abuts the support element, and a second configuration in which the second mounting face abuts the support element, by rotation relative to the support element about the main axis, to vary a space between the support element and the surface.

Description

(1) Embodiments of the present invention will now be described, with reference to the accompanying drawings, in which:

(2) FIG. 1 is a schematic perspective view of part of a building to which an external insulation system can be retro-fitted, according to a method of the present invention;

(3) FIGS. 2 to 8 are views of the building shown in FIG. 1, illustrating steps in a method of retro-fitting an external insulation system, and a retro-fit external insulation system, according to an embodiment of the present invention;

(4) FIGS. 9 and 10 are schematic plan views of the retro-fit external insulation system of FIGS. 2 to 8, showing further detail on steps in the method;

(5) FIG. 11 is an enlarged perspective view of a pre-formed surface finish element, forming part of the external insulation system;

(6) FIG. 12 is an exploded perspective view of a retro-fit external insulation system according to another embodiment of the present invention;

(7) FIG. 13 is a perspective view of an adjustable spacer, in accordance with an embodiment of the present invention, which has a use in the method and system of FIGS. 2 to 12;

(8) FIG. 14 is a view of the adjustable spacer which is similar to FIG. 13, showing the spacer containing flowable insulation material;

(9) FIGS. 15 to 17 are perspective views showing further steps in a method of retro-fitting an external insulation system, and a retro-fit external insulation system, employing the adjustable spacer of FIG. 13;

(10) FIG. 18 is a perspective view of an adjustable spacer in accordance with another embodiment of the present invention, shown in a partially assembled state, the spacer having a use in the method and system of FIGS. 2 to 12;

(11) FIG. 19 is a perspective view of first and second spacer components forming part of the spacer shown in FIG. 18;

(12) FIG. 20 is a perspective view of the spacer of FIG. 18 in a fully assembled state;

(13) FIG. 21 is an enlarged side view of part of the building shown in FIG. 1, illustrating optional further steps in the method, and optional further features of the system, of FIGS. 2 to 12; and

(14) FIG. 22 is perspective view of a bottom barrier member, employed in an optional further step in the method, and forming an optional further feature of the system, of FIGS. 2 to 12.

(15) Turning firstly to FIG. 1, there is shown part of a building 10 to which an external insulation system can be retro-fitted, according to a method of the present invention. It will be understood from the following description that the method/system of the present invention can be employed to retro-fit external insulation to a wide range of buildings, and in particular that the retro-fit external insulation system can be fitted to an external surface of a wall or walls of any suitable building.

(16) The building 10 may be of any suitable shape and dimensions, but is typically a domestic premises such as a house. The house 10 may be a terraced or semi-detached house, but may be any other suitable type of house including a detached house. The method of the present invention may also be applied to the external walls of apartment buildings.

(17) Turning now to FIGS. 2 to 8, there are shown views of the house 10 of FIG. 1 illustrating steps in a method of retro-fitting an external insulation system, and a retro-fit external insulation system, according to an embodiment of the present invention, the system indicated in the drawings by reference numeral 11.

(18) The house 10 includes a wall 12 which, in the illustrated embodiment, is a front wall of the house. The front wall 12 has an existing external surface 14, which has formed the outermost surface of the front wall 12. The house 10 is of a solid wall type, comprising a single wall component or skin of substantial construction, for example of masonry construction such as brick, stone or a combination of the two. Houses having walls of this type do not possess a cavity into which insulation material can be supplied, to reduce heat loss from the building. Whilst the method of the present invention has a use with a wide range of different types of buildings, having different wall constructions (and so not restricted to solid wall type buildings), the method does have a particular use with buildings having a solid wall construction.

(19) The method of the present invention generally comprises the following steps. Referring to FIG. 3, a plurality of support elements, indicated variously by reference numerals 16, 18 and 20, are mounted to the existing external surface 14 of the house 10. The support elements 16, 18 and 20 are typically mounted by means of suitable fixings, which will be discussed below.

(20) A plurality of surface panels are provided, which are shown variously in FIGS. 5 to 7 and which are indicated by reference numerals 22, 24, 26, 28, 30, 32 and 34, as well as numerals 78, 80 and 82. FIG. 9, which is a schematic plan view of the external insulation system, shows the surface panels 22 and 24 in more detail. The surface panels 22 to 34 and 78 to 82 each comprise an internal wall-facing surface and an external surface, the internal wall-facing surfaces of the panels 22 and 24 being shown in FIG. 9, indicated by reference numeral 36, and the external surfaces shown and indicated by reference numeral 38. Whilst only the panels 22 and 24 are shown in FIG. 9 and will be described in detail herein, it will be understood that the remaining panels 26 to 34 are of like construction, and that similar reference numerals will be employed in relation to common features of the panels.

(21) The surface panels 22 to 34 and 78 to 82 are arranged so that they cover at least a substantial part of the existing external surface 14 of the wall 12 and, in the illustrated embodiment, cover the entire existing external surface 14. The surface panels 22 to 34 are mounted to one or more of the support elements 16, 18 and 20, so that cavities 40 are defined between the internal wall-facing surfaces 36 of the panels, and the existing external surface 14 of the wall 12. These cavities 40 are shown in FIG. 9.

(22) Finally, a flowable insulation material 42 is supplied into the cavities 40, again as shown in FIG. 9. Only a part of one of the cavities 40 is shown filled with the flowable insulation material 42, for ease of illustration. It will be understood, however, that the cavities 40 are filled with the insulation material 42, to provide optimum insulating performance.

(23) The method and retro-fit external insulation system of the present invention addresses many of the problems with prior systems and methods, and enables fitting of external insulation system to a building in a much shorter timeframe than with the prior methods.

(24) In particular, the method and external insulation system of the present invention addresses numerous problems with prior methods and systems because it effectively involves the creation of a cavity which is external to the existing external surface of the building in question, and the filling of that cavity with a suitable flowable insulation material. This avoids the need to meticulously clean the external surface of the wall to which the insulation system is to be applied. Additionally, the use of time-setting adhesives, renders and the like can be dispensed with. Furthermore, the requirement to provide fixings extending through insulation material applied to the external surface of the building can be reduced, thereby reducing the risk of the formation of a cold bridge. As a result, the many different building trades which are involved in applying prior external insulation systems to buildings can be greatly reduced, thereby reducing the labour and cost involved in applying the external insulation system of the present invention to a building. Additionally, adverse weather conditions are of significantly less concern.

(25) The method and retro-fit external insulation system of the present invention will now be described in more detail.

(26) Returning to FIG. 2, a first step in the method is shown, which involves the positioning of insulation containment elements 44 and 46 at ground level, and similar such elements 48 and 50 in the region of window 52 and door 53 lintels, the lintels being embedded within the structure of the wall 12 and so not shown in the drawing. These insulation containment elements 44 to 50 are each elongate, taking the general form of boards or panels which are secured to the existing external surface 14 of the house 12, such as via designated brackets and fixings (not shown), supplied as part of a Kit of Parts for assembling the insulation system. The purpose of these boards 44 to 50 is to contain the flowable insulation material 42 which is subsequently supplied into the cavities 40, as shown in FIG. 9. However, the boards 44 to 50 may also facilitate drainage of any moisture that might collect in the cavities 40, and so may take the form of/comprise draining profiles.

(27) The support elements 16, 18 and 20 shown in FIG. 3 are each generally elongate, taking the form of beams, slats or spacers, and are typically of a material having insulating properties. Suitable materials include wood and wood based products such as wood composites, e.g. plywood. Materials of this type have a low heat transfer coefficient, reducing heat loss from the wall 12 where the support elements contact the existing external surface 14. Typical heat transfer coefficients of suitable materials may be no more than about 1 W/(mK), no more than about 0.75 W/(mK), no more than about 0.20 W/(mK), no more than about 0.15 W/(mK), no more than about 0.10 W/(mK) and may be as low as about 0.05 W/(mK). The heat transfer coefficients of suitable wood materials may be 0.17 W/(mK) for oak, and 0.12 W/(mK) for pine, measured across the wood grain. The support elements 16, 18 and 20 are generally vertically oriented, spaced apart across a width 54 of the wall 12. The support elements 16 are longer than the support elements 18 and 20, since they extend along a full height of the wall 12, indicated by numeral 56 in FIG. 3. The support elements 16, 18 and 20 are typically of a similar width, which may be of the order of 70 mm. Optionally however, the support elements 20, which are at intersection regions between adjacent panels, may be slightly wider.

(28) All of the support elements 16, 18 and 20 are secured to the wall 12 using suitable fixings, the fixings indicated generally by reference numeral 60 in FIG. 4. Only some of the fixings 60 have been labelled in the drawing, but the locations of the further fixings can clearly be seen. The fixings 60 extend through the support elements 16, 18 and 20 and penetrate the existing external surface 14 some distance into the wall 12, so that the support elements are securely anchored to the external surface. The fixings 60 will not be described in detail herein, but the skilled person will be well aware of fixings of suitable types which may be employed to secure the support elements 16 to 20.

(29) Turning now to FIG. 5, the surface panels 22, 24 and 26 are shown following mounting to the support elements 16, 18 and 20. The surface panels 22, 24 and 26 form a first set of surface panels which are mounted to the existing external surface 14 of the house 12, via the support elements 16, 18 and 20. The surface panels 22, 24 and 26 in this first set of panels extend generally to a first maximum height 62 above ground 64 level. As can be seen from the drawing though, the panels 22 and 24 accommodate the window 52, and so have portions which are of a lower height 66 above the ground 54 level.

(30) The panels 22, 24 and 26 are mounted to the support elements 16, 18 and 20 (as appropriate) using designated fixings (not shown), supplied as part of the Kit of Parts, and which will again be of a type readily understood by the skilled person. The fixings typically extend through interface zones provided adjacent edges of the respective panels. Referring for example to the surface panels 22 and 24, these comprise a number of interface zones, indicated by reference numerals 68 and 70 (panel 22), and 72 and 74 (panel 24). Advantageously, the fixings which are used to secure the surface panels 22 to 34 to the support elements 16 to 20 (and so to the existing external surface 14 of the wall 12) can be separate from the fixings 60 which are used to secure the support elements themselves. In this way, the formation of a cold-bridge, extending from the wall 12 through to the external surfaces 38 of the surface panels 22 to 34, can be avoided.

(31) Mounting of the first set of surface panels 22 to 26 effectively defines a first set of cavities 40, extending up to the first maximum height 62. The flowable insulation material 42 is then supplied into those cavities 40, prior to mounting of any further surface panels to the wall 12. This facilitates supply of the flowable insulation material 42 into the first set of cavities 40, and ready verification that the insulation material has properly filled the cavities. This is because the insulation material 42 only needs to fill the cavities 40 to the first maximum height 62, and it can readily be determined whether or not the insulation material has packed down into the cavities to fill them.

(32) Turning now to FIGS. 6 and 7, a second set of surface panels comprising the panels 28, 30, 32, 34 and 36 are then mounted to the existing external surface 14 of the wall 12, again via the support elements 16 to 20, as appropriate. The surface panels 28, 30 and 32 in the second set extend to a second maximum height 76 above ground 64 level, and are mounted to the support elements 16 to 20 in a similar way. Once again, flowable insulation material 42 is supplied into the cavities 40 defined between the internal wall facing surfaces 36 of the surface panels 28 to 32, and inspection of the cavities 40 carried out prior to mounting further surface panels.

(33) FIG. 8 shows the wall 12 following mounting of a third set of surface panels, whose locations are indicated schematically at 78, 80 and 82, and which extend up to the full height 56 of the wall 12. These panels 78 to 82 are mounted in the same way as described above, and so have with the cavities 40 which they define filled in the same fashion. Following mounting of this third set of panels 78 to 82, the entire existing external surface 14 of the front wall 12 of the house 10 has been covered.

(34) In a variation on the above, the cavities 40 may be filled with the flowable insulation once panels have been installed extending across the full elevation of the wall surface 14. In other words, the insulation material may only be supplied into the cavities once all of the panels have been installed, covering the wall surface 14.

(35) We now return to FIG. 9, and will refer also to FIG. 10, which is a view similar to FIG. 9 showing further steps in the method, and FIG. 11, which is an enlarged perspective view of a pre-formed surface finish arrangement 84 forming part of the system.

(36) The external surfaces 38 of the surface panels 22 to 34 and 78 to 82 comprise a decorative surface finish. Many different surface finishes could be provided, but in the illustrated embodiment, a brick effect surface finish is provided. This is achieved using a plurality of brick slips 86, which form a majority of the external surface 38 of each surface panel. The brick slips 86 are of a type known in the building industry, and are typically of suitable plastics (e.g. polymeric) material formed to provide a surface finish similar to a conventional masonry brick. Other suitable materials for the slips 86 include resin-based materials, cementitious materials and composites/mixtures thereof. The slips 86 are relatively thin, and are mounted on planar backing boards or sheets 88, which define the internal wall facing surfaces 36 of the surface panels. The backing boards 88 may be cement particle boards (or plaster board), but could be of any other suitable material including wood (or wood products such as fibreboard) and the like.

(37) The method involves carrying out a finishing procedure to form a desired surface finish, following mounting of the surface panels 22 to 34 and 78 to 82 to the support elements 16, 18 and 20. In the illustrated embodiment, a surface finish material is applied to the intersection region or regions between adjacent support panels. Referring particularly to FIG. 9, and to the interface region 58 between surface panels 22 and 24, the finishing procedure involves applying a surface finish material to that and other intersection regions.

(38) FIG. 11 shows a pre-formed surface finish arrangement 84, which may be a single pre-formed component, but typically comprises a plurality of further brick slips 90, which can be positioned so that they extend across the intersection region 58, straddling the adjacent surface panels 22 and 24. The slips 90 are positioned in the interface zones 70 and 72 of the panels 22, 24 (FIG. 5), effectively filling the interface zones with slips 90. All of the interface zones (e.g. 68 to 74) between adjacent surface panels are filled with such brick slips to provide the surface finish effect shown in FIG. 8. It will be understood that the interface zones 68 and 74, and indeed the interface zones of further surface panels, are interfaces between the panels and other parts or areas of the house 10, or indeed further buildings, rather than specifically between adjacent surface panels. When all the interface zones have been filled, a cement based material such as a mortar or grout is supplied into channels 91 between the slips 86 and 90, portions of such channels being shown in FIG. 9.

(39) The illustrated method comprises a further step of securing each surface panel to at least one adjacent surface panel. For example and referring to FIGS. 9 and 10, the surface panel 22 is secured to the adjacent surface panel 24. To this end, the surface panels 22 and 24 (and indeed the further surface panels employed in the method) comprise at least one interface component which cooperates with the adjacent panel. Interface components 92 and 94 are shown in the drawings, on the respective surface panels 22 and 24. The interface components 92 and 94 are moveable from positions where they are out of cooperation with the adjacent surface panel 24, 22 and a position where they cooperate with said adjacent panel. These positions are shown respectively in FIG. 9 and FIG. 10.

(40) The interface components 92 and 94 are deformable for movement between these positions, and to this end take the form of sheet or sheet-like components having a plurality of apertures (not shown). Typical suitable materials include meshes, which are preferably foldable to overlap the adjacent surface panel 22, 24 and which may suitably be of plastics, metal or metal alloy materials.

(41) The interface meshes 92 and 94 are typically folded back to the positions shown in FIG. 9 prior to mounting of the surface panels 22 and 24, or may be provided folded over, and in particular folded back to overlie the brick slips 86. Following mounting of the surface panels 22 and 24 to the support elements 16, 18 and 20 (as appropriate), the interface meshes 92 on the surface panel 22 are folded to cover the interface zones 70 on the panel 22, and to extend across and cover part the interface zone 72 on the adjacent surface panel 24. It will be understood particularly from FIG. 5 that a plurality of such interface members 92 and 94 are provided, to take account of the staggered pattern of the brick slips 86 shown in this embodiment. However, different brick patterns may be employed which will not require the provision of separate interface components.

(42) The interface mesh 94 on the surface panel 24 is then folded to overlie the interface mesh 92, as shown in FIG. 10. The brick slips 90 shown in FIG. 11 can then be applied over this arrangement of interface meshes 92 and 94, the slips 90 secured using an adhesive or cement-based material. The mesh structure of the interface meshes 92 and 94 provides a good key with the adhesive or cement-based material. A mortar or grout can then be provided in channels (not shown) between the brick slips 90 and slips 86 of the surface panels 22 and 24, to finish the surface effect. The overlapping meshes 92 and 94 are typically bedded into the backing board 88 with bedding adhesive on site, which will be allowed to set prior to the application of adhesive for the brick slips 90, and indeed the slips themselves. Ideally, this involves a single adhesive application, both for bedding the meshes 92, 94 and securing the slips 90 in place.

(43) The flowable insulation material 42 which is used to fill the cavity 40 may be one of a range of suitable flowable materials used in the building industry, such as for cavity wall insulation filling purposes. A typical suitable material comprises a large number of solid beads, pellets, granules or the like, indicated by numeral 93 in the drawings. These beads 93 typically have a time-setting coating such as an adhesive, which binds the beads together in the cavity 40. Insulation materials of this type are easily handled and supplied into the cavities 40. A particularly suitable insulation material is expanded polystyrene (EPS) beads.

(44) It will be understood from the above and the accompanying drawings that the surface panels 22 to 34 and 78 to 82 have a length, height and shape, and that the length, height and/or shape of at least one surface panel may differ from the length, height and/or shape of at least one other surface panel. This is best shown in FIG. 7. The method comprises pre-forming the surface panels to have the required length, height and/or shape prior to mounting the panels to the support element 16, 18 and 20. Advantageously, this can be carried out off-site, following an assessment of the house 10, including the shape of its wall 12, and the location of any obstacles such as the window 52, door 53 and further windows 96 and 98. The surface panels 22 to 34, 78 to 82 are manufactured of the required length, height and/or shape off-site, to speed the installation process. In particular, the backing boards 88 are cut to the desired shape, and the brick slips 86 applied to the backing boards in a suitable number and pattern.

(45) One further advantage of the retro-fit external insulation system of the present invention is that the various components of the system can be provided in a flat-pack kit comprising the surface panels 22 to 34, 78 to 82 of required shapes and the various support elements 16, 18 and 20. The insulation beads 93 are typically supplied in bulk form in a suitable container, ready for blowing into the cavities 40 using suitable handling equipment of a type known in the industry. Furthermore, the invention encompasses a kit of parts which can be arranged to form a retro-fit external insulation system for a building, and the kit of parts may comprise a group comprising a plurality of surface panels, the surface panels each having a length, a height and a shape (or profile), in which the length, height and/or shape of at least one surface panel differs from the length, height and/or shape of at least one other surface panel. Some (not all) of the surface panels may be selected from the group for mounting to the support elements. The group of panels may comprise a range of panels of length, height and/or shape suited to a wide range of buildings, so that panels appropriate to the building in question can be selected for covering said part of the existing external surface of the wall.

(46) Turning now to FIG. 12, there is shown an exploded perspective view of a retro-fit external insulation system according to another embodiment of the present invention, the system indicated generally by reference numeral 11a. Like components of the system 11a with the system 11 of FIGS. 2 to 11 share the same reference numerals, with the addition of the suffix a.

(47) The system 11a is in-fact of similar structure to the system 11, and indeed installed in a similar way, differing primarily in terms of support elements 16a of the system. Specifically, in this embodiment, the support elements 16a are again elongate members such as beams, slats or spacers. However, the elongate members 16a are coupled to a plurality of support pads, blocks or the like, indicated by numeral 100. The pads 100 are spaced apart along a length direction of the elongate members 16a. The elongate members 16a can be provided integrally with the support pads 100, or separately and subsequently coupled together, either on or off site. Typically, the pads 100 will be of a similar material to the elongate members 16a. The support pads 100 contact and are secured to the existing external surface 14 of the wall 12, using suitable fixings (not shown). The surface panels 22a are therefore mounted to the wall surface 14 via the elongate members 16a and the pads 100. Advantageously, the support pads 100 provide a reduced area of contact with the existing external surface 14 of the wall 12, and so reduced heat transfer from the wall. In a variation on this embodiment, the elongate members 16a may be dispensed with, so that the support pads 100 directly contact the wall-facing surfaces 36 of the surface panels 22a.

(48) FIG. 12 also shows further parts of the system 11a, and indeed steps in the associated method, which may also apply to the system 11 of FIGS. 2 to 11. In particular, a decorative surface finish comprising brick slips 86a are provided in sheet-form, and an intermediate, reinforcing component in the form of a mesh 102 is provided between the sheet of brick slips 86a and a backing sheet 88a. The mesh 102 is suitably of a plastics, metal or metal alloy material, and is bonded to the backing sheet 88a using adhesive 104. The mesh 102 provides a good key for bonding the sheet of brick slips 86a to the backing sheet 88a, via a further adhesive 106 (although it may be possible to use a single layer of adhesive to both bond the mesh 102 to the backing sheet 88a, and the sheet of brick slips 86a to the backing sheet, via the mesh).

(49) In a variation, the reinforcing component (mesh 102) may be provided integrally with the decorative surface finish component (the sheet of brick slips 86a). This may be achieved by embedding the mesh 102 into a rear of the sheet of brick slips 86a, which may be facilitated where the slips are of a moulded or similarly formed material, such as a plastics material where, e.g. the slips can be formed by extruding the plastics material over the mesh.

(50) Suitably and whether or not the reinforcing component (mesh 102) is provided integrally with the decorative surface finish component (the sheet of brick slips 86a), the surface finish component may be coupled to the backing sheet 88a using a cement-based material, such as a mortar. Apertures may be provided in the sheet of brick slips 86a, suitably in the grout lines between slips, so that the mortar squeezes through apertures in the mesh 102 and into the grout line areas during fitting to the backing sheet 88a. In this way, the mortar can be used both to secure the sheet of brick slips 86a to the backing sheet 88a, and also to at least partially fill the grout lines, which can be subsequently smoothed to a desired finish. This may avoid a requirement to separately supply mortar/grout into the grout lines.

(51) Turning now to FIG. 13, there is shown a perspective view of an adjustable spacer, in accordance with an embodiment of the present invention, which has a use in the method and system of FIGS. 2 to 12. The spacer is indicated generally by reference numeral 108, and is also shown in FIG. 14, which is a view similar to FIG. 13, but showing the spacer containing flowable insulation material 42.

(52) The spacer 108 is for mounting an elongate building element to a surface so that a space is defined between the building element and the surface. In the illustrated embodiment, in which the spacer is used in the method and system of FIGS. 2 to 12, the building element is the support element 16, whilst the surface is the existing external surface 14 of the building 10. This is shown in FIGS. 15 to 17, which are perspective views of the spacer 108 illustrating further, optional steps in the method and system of FIGS. 2 to 12. The space is indicated by numeral 110, shown in FIG. 16, and is the space between the support element 16 and the external surface 14.

(53) The spacer 108 is adjustable to vary a dimension of the space 110, and comprises a first end 112 adapted to abut the surface 14, and a second end 114 adapted to abut the support element 16. The second end comprises a first mounting face 116 which is at a first distance a from the first end 112 of the spacer 108, and a second mounting face 118 which is at a second distance b from the first end 112 of the spacer, the second distance being greater than the first distance. The spacer 108 is adjustable between a first configuration in which the first mounting face 116 is arranged to abut the support element 16, and a second configuration in which the second mounting face 118 is arranged to abut the support element 16, so that the space 110 between the support element 16 and the surface 14 can be adjusted.

(54) The spacer 108 is a one-piece spacer, which facilitates positioning of the spacer (compared to prior such spacers) and indeed assembly of the system 11, as will be described below. The spacer 108 is preferably of a material having insulating properties. Suitable materials include plastics materials, such as a Polycarbonate material. The spacer 108 may be of a material having a relatively low heat transfer coefficient, which may be no more than about 0.20 W/(mK).

(55) The second end 114 of the spacer 108 actually comprises a plurality of further mounting faces, numbered respectively 120, 122 and 124, each of which is at a respective further distance c, d and e from the first end 112 of the spacer than the preceding mounting face. The spacer 108 is adjustable between the first configuration, the second configuration, and any one of a plurality of further configurations in which a respective one of the further mounting faces 120 to 124 is arranged to abut the support element 16.

(56) In the illustrated method and system, the adjustable spacer 108 is used to mount the support element 16 to the building surface 14. The step of mounting the support elements 16 to the surface 14 comprises positioning at least one (and typically a plurality) of the adjustable spacers 108 between each support element 16 and the surface 14, and adjusting the spacer 108 to vary the space 110 between the support element 16 and the surface 14. Mounting the support elements 16 to the surface 14 using the spacers 108 facilitates adjustment of the space 110 to accommodate one or more of: variations in the external surface 14 (e.g. where portions of the surface are not in a common plane); variations in dimensions of the surface panels 22 and/or the support elements 16; and variations in a fit of the surface panels 22 and/or support elements 16 to each other and/or to the surface 14. The spacers 108 can also facilitate adjustment of a dimension of the cavities 40.

(57) The mounting faces 116 to 124 of the spacer 108 in fact comprise a plurality of mounting face portions which together define the mounting face. The mounting face portions are discrete, and given the numerals 116a/b, 118a/b, 120a/b, 122a/b and 124a/b, respectively. The mounting faces 116 to 124 are spaced around a periphery of the spacer 108 at the second end 114. As can be seen, the spacer 108 is hollow, being of a generally cylindrical tubular shape, and the mounting faces 116 to 124 are spaced around a circumference of the spacer at the second end 114.

(58) The mounting faces 116 to 124 are defined by supports, which take the form of ledges, shelves or the like. The ledges 116a/b to 124a/b forming each mounting face 116 to 124 are arranged transverse to a main axis 126 of the spacer 108 (extending between the first and second ends 112, 114), and in the illustrated embodiment are arranged substantially perpendicularly to the main axis. The ledges 116a/b to 124a/b of each mounting face 116 to 124 are arranged on a line passing through a centre of the spacer 108, and so effectively arranged across a diameter of the spacer.

(59) The ledges 116a/b to 124a/b of each mounting face 116 to 124 are also provided at common distances a to e from the first end 112 of the spacer 108, and cooperate to define an abutment for the support elements 16. This is best shown in FIGS. 15 to 17. FIG. 15 shows a spacer 108 positioned on the external wall surface 14. A support element 16 is introduced to the spacer 108, and positioned in abutment with the ledges 116a/b forming the first mounting surface 116. In this way, the support element 16 is effectively located at the first distance a from the wall surface 14. Effectively, the spacer 108 defines a channel, slot or the like 142 (FIG. 15) at the second end, which receives the support element 16, and which restricts relative rotation between the spacer and the support element. The support element 16 and spacer 108 are then secured to the wall 12 using a suitable anchor or fixing 128, which passes through an interior cavity 129 of the spacer 108 and into the wall. Surface panels 22 (not shown in these Figs.) are then secured to the support element 16, and flowable insulation material 42 supplied into the cavities which are defined between the surface panels 22 and the wall surface 14.

(60) The spacer 108 is thus clamped between the support element 16 and the wall surface 14, via the anchor 128, which passes through the support element and the spacer into the wall 12. The spacer 108 provides a substantially uniform distribution of load on the wall 12, during use, due to its hollow, cylindrical tubular shape.

(61) If it is desired to adjust the spacer 108, to account e.g. for variations in a dimension of the space 110, then the spacer can be adjusted between its different configurations by rotating it about its main axis 126, so that a different mounting face selected from the faces 118 to 124 can be chosen for abutting the support element 16. For example, a variation in the wall surface 14 may be such that the dimension of the space is equivalent to the dimension c defined by the mounting face 120. The spacer 108 may thus be rotated to bring the ledges 120a/b defining the mounting face 120 into a position where they can abut the support element 16.

(62) The spacer 108 also comprises restraints for restraining rotation of the spacer relative to the support element 16, each of which extend in a direction which is generally parallel to the main axis 126 of the spacer. A number of pairs of restraints 130a/b, 132a/b, 134a/b, 136a/b and 140a/b are provided, which are arranged to cooperate with lateral sides or edges of the support element 16. The restraints 130a/b to 140a/b cooperate with a respective ledge of one of the mounting faces 116 to 124, so that they together define a channel, slot, recess or the like for receiving the support element 16. The restraints 130a/b to 140a/b restrain rotation of the spacer 108 relative to the support element 16, whilst the mounting faces 116 to 124 support the element 16 at the respective distance a to e from the first end 112 of the spacer. For example and as shown in FIGS. 15 to 17, the spacer 108 is positioned in its first configuration, in which the ledges 116a/b of the first mounting face 116 are arranged to receive and abut the support element 16. The support element 16 is effectively seated on the ledges 116a/b at the distance a from the wall surface 14, and rotation of the spacer 108 is restricted by the restraints 130a/b (and 140a/b) which, together with the ledges, effectively define a channel 142 (FIG. 15) which receives the support element 16.

(63) Turning now to FIG. 18, there is shown a perspective view of an adjustable spacer, in accordance with another embodiment of the present invention, which has a use in the method and system of FIGS. 2 to 12. The spacer is indicated by reference numeral 108. Like components of the spacer 108 with the spacer 108 of FIG. 13 share the same reference numerals, with the addition of the suffix .

(64) In this embodiment, the adjustable spacer 108 comprises a first spacer component 144 defining a first end 112 of the spacer, which is adapted to abut the external wall surface 14. The spacer 108 also comprises a second spacer component 146 defining a second end 114 of the spacer. The spacer components 144 and 146 are shown separately in FIG. 19. The second end of the second spacer component 146 comprises a mounting face 116 which is adapted to abut the support element 16. The mounting face 116 is defined by two ledges or shelves 117, which together effectively form a channel or slot that receives the support element 16.

(65) The first and second spacer components 144, 146 are movably coupled so that a distance between the first end 112 and the mounting face 116 of the second end 114 can be varied, to adjust the space 110 (FIG. 16) between the support element 16 and the surface 14. The spacer 108 also comprises a restraining component 148 for selectively restraining movement of the second spacer component 146 relative to the first spacer component 144 in a direction towards the first end 112, to fix the distance between the first end and the mounting face 116 of the second end 114, and so a dimension of the space 110.

(66) Typically, one of the first and second spacer components 144 and 146 is a female component and the other a male component, the female component being shaped to receive the male component in a sliding fit. In the illustrated embodiment, the first component 144 is a male component and the second component 146 is a female component. The restraining component 148 is positioned around one of the spacer components 144 and 146, and arranged to abut the other one of the spacer components, to thereby restrain movement of the other spacer component. The restraining component 148 is adapted to be provided at the first end 112 of the spacer 108, and to abut the second spacer component 146 and the wall surface 14.

(67) The restraining component 148 is shaped to fit around one of the spacer components, in this embodiment the first spacer component 144. This is shown in FIG. 20. The restraining component 148 is elastically deformable for engagement around the first spacer component 144, and is typically a sprung component. The restraining component 148 suitably takes the form of a shim, collar, cuff or the like, and may in particular be split, in the general shape of a split-ring, comprising a gap 150 defined between circumferential edges 152 of the ring, the ring being elastically deformable so that the gap can be expanded to fit the ring around the first spacer component 144.

(68) Typically, the restraining component 148 is cut to the required length, to suit the dimensions of the space 110 which the spacer 108 is required to bridge. However, the spacer 108 may comprise a plurality of restraining components 148 (not shown), each having a respective length in a direction along a main axis 126 of the spacer (extending between the first and second ends 112, 114). In this way, a spacer 108 of a desired length may be formed, for defining a desired distance between the first end 112 of the spacer and the mounting face 116 of the second end 114.

(69) Each of the spacers 108 and 108 disclosed herein are hollow, defining an internal cavity 129/129 which extends between its first and second ends. As discussed above, the internal cavity can receive flowable insulation material 42, which may be charged into the cavity prior to installation on the wall surface 14, or when the material is supplied into the cavities 40. The internal cavity can also receive the anchor 128 used to secure the support element 16 to the surface 14. The spacer 108 may include an aperture in the mounting face 116 through which the anchor 128 can pass. The spacers 108/108 also comprise at least one aperture 154, 154 extending through a side wall of the spacer, the aperture(s) communicating with the internal cavity 129, 129. This facilitates the flow of insulation material 42 into/out of the cavity 129, 129. At least one such aperture 154, 154 may be provided at/adjacent the first end 112, 112 of the spacer 108, 108.

(70) Whilst the adjustable spacers have been described as forming part of the method/system/kit disclosed herein, it will be understood that they may be employed in other methods, systems and kits. The elongate building element may be any desired building element. The building element may be a support element for mounting a surface panel to an external surface of a wall of a building, such as is employed in the present method/system/kit. However, the building element may be a joist, beam or other element used for supporting a roof, floor, deck or the like on or from the surface. Indeed, the surface may be any suitable surface and is not restricted to a wall, and may be a roof or floor (internal or external).

(71) Turning now to FIG. 21, there is shown an enlarged side view of part of the building 10 shown in FIG. 1, illustrating optional further steps in the method, and optional further features of the retro-fit insulation system 11, of FIGS. 2 to 12. Whilst the further steps/features are described with particular reference to the method and system 11 of FIGS. 2 to 12, it will be understood that the further steps/features have a use in all of the methods/systems disclosed in this document. In particular, the further steps/features may form part of a method/system employing an adjustable spacer, as shown and described in FIGS. 13 to 20.

(72) FIG. 21 shows a top or upper barrier member 156 which closes the tops of at least some of the cavities 40, typically those which are uppermost, adjacent a top 157 of the wall 12. One such cavity 40 is shown in the drawing, and has a top 158. The top barrier member 156 prevents the insulation material 42 from flowing out of the tops 158 of cavities 40 adjacent the top 157 of the wall 12, particularly where the insulation takes the form of beads or pellets (as shown in the drawing). The top barrier member 156 is arranged so that it allows water vapour to escape from the cavities 40, typically by means of a plurality of apertures (not shown). This is advantageous in that it allows any water vapour which has entered the cavities 40 through the building wall 12 to pass up and out of the cavities, reducing the risk of the vapour condensing and becoming trapped within the cavities. This may be achieved by providing a top barrier member 156 formed from a flexible material, which may be a flexible mesh-type material. This may provide the advantage that the top barrier member 156 can flex to accommodate the flowable insulation material 42 supplied into the cavities 40, which may cause the barrier member to flex outwardly. Alternatively, the top barrier member can be formed from a solid strip or sheet provided with apertures.

(73) Typically, a single top barrier member 156 will be provided extending across the width of the building wall 12, although multiple barrier members may be provided in appropriate/desired circumstances. The top barrier member 156 is arranged so that it restricts liquid water from entering the cavities 40. This is achieved by providing apertures which are sized to permit the passage of water vapour but to restrict the passage of liquid water. The skilled person will readily appreciate the size of apertures required to achieve this. Where the top barrier member 156 is of a flexible material, suitable materials include plastics materials such as PVC.

(74) Turning now to FIG. 22, there is shown a perspective view of a lower barrier member 160, which closes the bottoms of at least some of the cavities 40. Again, one such cavity 40 is shown in the drawing, and has a bottom 162. The bottom barrier member 160 prevents the insulation material 42 from flowing out of the bottoms 162 of lowermost cavities 40, adjacent a bottom 164 of the wall 12, particularly where the insulation takes the form of beads or pellets. The bottom barrier member 160 is arranged so that it allows liquid water to escape from the cavities 40. This is advantageous in that it allows any liquid water within the cavities 40, such as rainwater or condensed water vapour, to drain out. This is achieved by providing the bottom barrier member 160 with a plurality of apertures 166. Typically, a single bottom barrier member 160 will be provided extending across the width of the building wall 12, although multiple barrier members may be provided in appropriate/desired circumstances.

(75) The flow of water vapour and/or liquid water out of the cavities 40 is facilitated by selecting a suitable insulation material 42. The use of an insulation material comprising a plurality of particles of a solids material, such as beads, pellets or granules 43, is particularly beneficial. This is because a plurality of channels are defined between the beads 43, through which liquid water can pass to the bottom barrier member 160 and so exit the cavities 40, and through which water vapour can pass to the top barrier member 156 and so similarly exit the cavities.

(76) In the illustrated embodiment, at least one dimension of the bottom barrier member 160 is adjustable. The dimension is a depth of the barrier member, taken in a direction between the panels (the panel 22 being shown in the drawing) and the wall 12, as indicated by the line 168. This provides the ability to accommodate cavities 40 of different dimensions (depths). To achieve this, the bottom barrier member 160 comprises a first part 170 which is mountable on the external surface 14 of the wall 12, and a second part 172 which is mountable to at least some of the panels (or vice-versa). The second part 172 is shown mounted to the panel 22. The first and second parts 170, 172 are coupled together so that they are movable relative to one-another, to vary the depth 168 of the barrier member 160. This may be achieve in numerous ways, but suitably can be achieved employing a sliding arrangement, such as a tongue-and-groove arrangement, as shown at 174 in the drawing.

(77) FIG. 21 also shows a cover member 176, which is positioned over the top barrier member 156, and which prevents liquid water (e.g. rainwater) from falling on to the upper barrier member. Typically, the cover member 176 will be positioned below a gutter (not shown) located adjacent the edge of a roof (not shown) of the building 10, to catch rainwater falling from the roof. To this end, the cover member 176 is impermeable to liquid water. A single cover member 176 may be provided extending across the width of the building wall 12, although multiple cover members may be provided in appropriate/desired circumstances.

(78) The cover member 176 is also shaped to define a wind guard 177 which overlaps tops of the panels, a top 178 of the panel 22 being shown in the drawing. This helps to prevent rainwater from being blown back on to the top barrier member 156. The cover member 176 defines a lower surface 180 which faces towards an upper surface 182 of the top barrier member 156. The lower surface 180 facilitates condensation of water vapour escaping from the cavities 40, and so forms a condensing surface. The cover member 176, in particular the lower surface 180, is arranged so that it is inclined relative to the horizontal and/or the top barrier member 156, to facilitate the flow of water which has condensed on the surface 180 off the cover member. Drainage holes (not shown) may be provided in a lower portion 184 of the wind guard, for drainage of collected water.

(79) Typically, a sealant material 186 is applied to the wall 12 in the region where the cover member 176 is to be mounted, via a securing bolt 188. When the bolt 188 is tightened, it squeezes sealant 186 upwards, which can then be shaped to seal an interface between the wall 12 and the cover member 176, as shown in the drawing. Further sealant can 186 be applied at the intersection, if required. The bolt 188 also serves for clamping a mounting member for the top barrier mesh 156 to the wall 12, which may be a mounting plate and which may be provided integrally or coupled to the mesh. Suitably, an insulating member such as a plate (not shown) may be located between the cover member 176 and the mounting plate 190, to reduce or avoid formation of a cold-bridge.

(80) Various modifications may be made to the foregoing without departing from the spirit or scope of the present invention.

(81) For example, the decorative surface finish may be a cement-based surface finish effect, such as a surface render, roughcast/pebbledash, stucco or plaster.

(82) The surface panels may comprise a backing sheet or board forming the internal wall-facing surface, and a decorative surface component forming at least part of the external surface of the panel. The decorative surface component may be provided integrally with the backing sheet or may be applied subsequently.

(83) The finishing procedure may comprise applying a surface finish material to a substantial part of (and optionally all of) the external surfaces of the surface panels. This step may comprise applying a cement-based surface finish material to the external surfaces of the panels. The cement-based surface finish material may be a surface render, roughcast/pebbledash, stucco, plaster or the like.

(84) The flowable insulation material may be a time-setting fluid or gel-based material, for example a foam. The flowable insulation material may be a fibrous material, in particular a chopped fibre type insulation. As is known in the industry, this comprises a large number of short, lightweight fibres which can be blown into the cavities (and so are flowable). Combinations of different flowable insulation materials may be employed.

(85) Any other suitable material can be used for the support elements, including wood-based materials such as MDF or chipboard, or plastics materials. The support elements may be arranged so that they are substantially horizontally oriented, spaced apart across a height dimension of the wall. Vertically and horizontally oriented elements may be employed, and/or potentially transversely oriented elements. Vertical orientation is preferred though as this eases supply of the insulation into the cavities, under the action of gravity.

(86) One or more panel may be coupled to one or more other panel in such a way that it is not necessary to mount said panel to a support element. Said panel may effectively be supported by an adjacent panel or panels.

(87) The step of mounting the support elements to the external surface may comprise: positioning at least one adjustable spacer between at least some of the support elements and the panels, optionally between each support element and a respective panel or panels, the spacer comprising a first end which abuts the panel and a second end which abuts the support element; and adjusting the spacer to vary a space between the support element and the panel. The system/spacer may be correspondingly arranged.