GB2360540A

GB2360540A - Hinged sealing flap for windows

Info

Publication number: GB2360540A
Application number: GB0102086A
Authority: GB
Inventors: Anthony Lee Hughes
Original assignee: Epwin Group PLC
Current assignee: Epwin Group PLC
Priority date: 2000-01-26
Filing date: 2001-01-26
Publication date: 2001-09-26
Also published as: GB0102086D0; GB0001811D0

Abstract

The joint 92 between a window frame 90 and an overlying lintel 91 is sealed by two separate means:- (i) a deformable seal 94 attached to either the frame or the lintel, (ii) a hinged flap 95 attached to either the frame or lintel and bearing against the other. These two means may be combined into a single component and the deformable seal may have a trefoil shaped cross-section. Also disclosed are hinged flaps mounted on the glazing unit and biased to bear against the window frame. In a further disclosure, a frame incorporates an element for closing the wall cavity. This element may have a clip or flange for engaging with the glazing unit, and it may have a part which penetrates the cavity and engages its walls via legs. Also disclosed are an alignment adjustor for the glazing unit, a removable cill attached to the glazing unit, a glazing unit with a recess for receiving a panel, and a multiple piece, interlocking window frame.

Description

2360540 WINDOW FRAME CONSTRUCTION The present invention relates to the

construction of a window frame, to a method of making such a window f rame, and to the combination of a window f rame and a window unit received within the f rame. It is particularly, but not exclusively, concerned with windows in new buildings, where the building is built around the window frame and the window unit is inserted into the frame.

When constructing a building, it is known, for the f rame for a window to be provided as an integral structure, and for the walls of the building to be built around that frame, a lintel be provided extending above the unit and resting on the walls, and the walls then built up further on the lintel. The frame defines an opening into which a window unit may be received. An example of such a structure is disclosed in GB2228033.

Where the wall is a cavity wall, it is usual for a part of the frame to project into the cavity, so that the frame also acts as a cavity closure. In GB2228033, that cavity closure was in the f orm of a box section.

In practice, existing window units need to be sealed to the walls across the f rame, and it is usual to use a liquid sealant to achieve this. The frame is fitted in place, the walls built around it, the window unit fitted, and then sealant applied. This is inconvenient, not only because the application of sealant is an additional step 2 in the building operation, but also because it may be inconvenient to provide access to the outside of the window unit, e.g. in high buildings.

The present invention therefore seeks to provide a frame for a window, for receiving a window unit, which does not need such a liquid sealant. The present invention has several aspects, concerned with different features which enable such a sealant to be avoided.

When walls are built around a frame for a window, there is inevitably some uncertainty in the exact height of walls adjacent to the top of the frame. Even small variations in the thickness of the mortar courses may mean that the top of the frame does not exactly match the top of a brick or block layer. Then, when the lintel is f itted over the frame, there is then a gap between the frame and the lintel. The first aspect of the invention therefore proposes that a seal be provided at an upper part of the top surface of the frame, which seal comprises two parts. The first part is a resiliently deformable seal attached to either the lintel or the frame and adapted to abut against the other in a sealing manner, and the second part is a pivoting flap hinged so as to bear against the frame or lintel and close the gap between the frame and lintel.

In such an arrangement, the resiliently deformable seal acts as a main seal, but the flap provides a more rigid seal, which is preferably at an outer point of the 3 f rame so as to provide the appearance of a frame trim to preserve the aesthetic appearance of the frame.

The two seals may be co-extruded, to form a single unitary element which can be attached to the frame or lintel. Normally, such an element will be attached to the frame by suitable fixing means. Alternatively, the two seals may be separate elements. Since both the resiliently deformable seal and the flap are able to move, they can adjust to variations in spacing between the other part of the frame and the lintel. The resiliently deformable seal is preferably shaped in the form of a trefoil, with the upper lobe contacting the lintel, since this shape prevents excessive deformation of the resiliently deformable seal due to relative movement of the frame and lintel during manufacture.

In such an arrangement, it is normal for the frame to be positioned, the wall built around the frame, and then a window unit inserted into the frame. The window unit preferably comprises glazing and a surrounding mounting which engages the window frame to secure the window unit into the frame. The window unit may be retained by suitable clips. Preferably, at least one of those clips is incorporated as a profiled strip, preferably of metal. That clip or clips is formed by one or more upstanding flanges in the strip which fit into a corresponding recess in the part of the frame which also acts as a cavity closure, with the flange abutting 4 against a rachet arrangement on the window unit. The fact that the clip is mounted in the cavity closure part of the frame means that it is held f irmly in place.

There may be a plurality of such clip arrangements located around the sides and bottom of the frame, with a differently shaped clip at the upper part, to allow for small variations in the size of the window unit relative to the frame. Such use of a clip or clips incorporated in a strip received in the window frame represents a second independent aspect of the present invention.

Moreover, the window unit may have a hinged trim piece thereon extending at least along the upper surface thereof, which trim piece is biased so as to bear against the frame, again providing a seal and preserving the aesthetic appearance of the structure. This represents a third independent aspect of the present invention.

In GB2228033, the surface of the frame forming the cavity closure had an upstanding flange, which formed a shoulder against which frame of the window may be abutted. A further aspect of the present invention develops this further, by providing a deformable seal on the window unit which will abut that flange, thereby improving the seal effect. A tortuous path for water ingress is formed and the flange which path is itself closed by the seal thereby minimising the risk of water ingress. This represents a fourth independent aspect of the present invention.

The window unit may be shaped so as exactly to f it the interior of the f rame. However, many window components are already known, and it is preferable that existing window components may be fitted to a frame incorporating features of the present invention.

Therefore, the window unit may include one or more adjustment members which fit to the rest of the window unit. Preferably, such adjustment members are provided on three sides of the window unit so as to enable the window unit to conform precisely to the frame. It would be possible, of course, for adjustment members to be provided on all four sides of the window unit, but this is not necessary as the lower part of the adjustment member may provide sufficient adjustment to enable the window unit to fit the upper edge of the opening of the frame. This is particularly useful where a part of the window unit is attached to the frame by a clip which projects from the frame. Where the window unit has a rachet which engages with the clip projecting from the frame, as in the second aspect of the invention, that clip structure may be provided on the window unit. The use of such an adjustment member therefore represents a fifth aspect of the present invention.

Normally, window units are provided with cills which are integral with the unit. With the present invention, it is possible to provide a separate cill piece which secures to the adjustment member of the window unit.

6 This provides the advantage that the cill piece may be replaced if it gets damaged, and represents a sixth aspect of the present invention. Such a cill piece may extend over the projecting flange and resilient seal of the fourth aspect.

It is common for internal panels to be fitted within the window opening, usually to be inside the window glazing, to provide an aesthetic covering of the brick or block structure forming the window reveal itself.

Preferably, the window unit has a groove or recess therein on its inside surface which will form the surface of the unit inside the building, which groove may then receive the panel. This represents a seventh aspect of the present invention. Where the window unit includes an adjustment member, as in the fifth aspect, the groove may be formed between a flange on that adjustment member and the rest of the window unit. A groove thus formed may extend around all four sides of the frame, although it is usually more convenient for it to extend around three sides, and for a corresponding groove be provided in an upper part of the frame, rather than in the window unit.

As has been mentioned previously, GB2228033 discloses a window frame in which a box section part of the frame into the wall cavity. In GB2228033, that box section will fill the cavity, with the sides of the box section abutting against the brick or block courses. However, when building a wall, it is common for small 7 amounts of mortar to be squeezed from between the courses into the cavity. In the arrangement disclosed in GB2228033, such mortar would then disrupt the interface between the box section and the bricks or blocks. This could add strains to the frame which are undesirable as they could cause it to be deformed and thereby reduce the sealing effect of the frame.

Therefore, according to an eighth aspect of the present invention, the part of the frame which extends into the cavity is in the form of a box section, but which box section has projecting legs, which legs will rest on the inner surface of the cavity, thereby holding the box section clear of the brick or block courses.

Therefore, small gaps are formed between the box section and the brick or block courses, which permit small amounts of mortar to be received without causing deformation or damage to the frame. Such legs may be provided along the bottom and sides of the frame, but are less necessary at the top since the top will be covered by a lintel, rather than directly covered by bricks or blocks.

Normally, the sides, bottom and top of the frame are formed by separate extrusions which are secured together to define the rectangular or square shape of the frame.

Preferably, joining pieces are provide which have projecting parts which fit into corresponding openings in box sections of the parts of the frames to be joined, 8 thereby acting both as a joining piece and as a closure for one or both of the respective box sections of the corresponding components. This is particularly important where the top of the frame is Joined to the sides, since the top of the frame may incorporate ventilation passages, and thus it is important that insects or other objects entering the upper part of the frame cannot pass therefrom to other parts of the frame. This use of a joining piece which also acts as a closure for a box section part of the frame represents a ninth aspect of the present invention.

Preferably, the ninth aspect is developed by making the joining pieces adjustable, to permit lateral displacement of the frame components to be joined.

is Other features may be incorporated into the window unit or frame. For example, the upper part of the frame may be provided with a ventilation path therethrough.

The cavity closure part of the frame may be generally planer as in GB2228033, but other frame constructions are also possible such as box section.

An embodiment of the present invention will now be described in detail, by way of example, with reference to the accompanying drawings, in which:

Fig 1 is a sectional view through the lower part of a frame/window unit assembly embodying.the present invention; Fig 2 is a sectional view through a side part of the 9 frame/window unit assembly of Fig 1; Fig 3 is a sectional view through the top part of the frame/window unit assembly of Fig 1; Fig 4 shows a joining member which may be used to join the side and top parts of the frame shown in Figs 2 and 3; Fig 5 shows a modification of the joining member of Fig 4, permitting adjustment; Fig 6 shows a modification of the lower part of the frame/window unit assembly of Fig 1; and Fig 7 shows a modification of the top part of the frame/window unit assembly of Fig 3.

As has previously been mentioned, in order to form a window structure, a frame is provided which is fitted in is place, the walls built around the frame, a lintel positioned over the frame, and the walls then continued.

The frame defines an opening for a window unit. Thus, the frame comprises a lower part extending generally horizontally and resting on the course of bricks or blocks, side parts extending vertically, and a top part completing the frame. Depending on the size and shape of the window, the resulting frame may be square or rectangular.

Fig 1 shows a sectional view through the lower part of the frame. The frame of this embodiment is intended to fit between an outer course 10 and an inner course 11 of bricks or blocks, with there being a cavity 12 between those courses. The frame has a fascia part 20 which extends across the cavity 12 to close it and a box section part 21 then extends into the cavity. That box section 21 has projecting legs 22, 23, 24 which extend from the box section 21 to abut against the courses 10, 11 of the wall. At the junction of the fascia part 20 and the box section 21 is a recess 25 which receives a metal strip 26. Legs of that strip are covered by lips 27 of the fascia part 20, so as to hold the strip 26 in place. The strip 26 has flanges 28 projecting upwardly therefrom. There is also a flange 29 which projects upwardly from the fascia part 20 adjacent the inner edge of the outer course 10 of bricks or blocks. The strip 26 may be formed as an elongate extrusion cut to length to is fit the frame.

In many ways, the resulting structure is similar to known cavity closure structures, such as that known from GB 2228033. However, the provision of the legs 22, 23, 24 is important, as they act to space the box section 21 from the inner surfaces of the courses 10, 11. This spacing permits mortar or other material to squeeze from between individual bricks or blocks in the courses 10, 11 to be held within the spaces between the box section 21 and the courses 10, 11. This means that such material does not deform the box section 21, so that the structural integrity of the cavity closure is maintained.

The resulting structure forms the lower part of the 11 frame, and there are side and upper parts of the frame which will be described later. However, Fig 1 also shows a lower part of a window unit which is received in that frame. That window unit comprises a glazing retaining unit 40 glazing (not shown) and an adjustment member 41 on at least three sides of the window unit.

Adjustment member 41 of hollow box crosssection which extends around three sides of the opening frame defined by the frame into which the window unit is received causing the glazing retaining unit 40 to conform precisely to the frame. The base of the glazing retaining unit 40 is securely snapped on to the top of the adjustment member 41 by means of clips 49 on the base of that unit 40 which engage with recesses 60 in the top of the inner and outer edges of the adjustment member 41.

The mating sides of the glazing retaining unit 40 and the adjustment member may be clipped together as extrusions and cut to appropriate length.

The bottom of the inner and outer edges of the adjustment member 41 each have an outwardly protruding clip, 47 and 42 respectively, attached thereto, and an outwardly pointing flange, 46 and 43 respectively, above that-clip. The clip 42 holds a seal 44. The points of these f langes are in the same plane as the inner and outer edges of the glazing retaining unit. The lower edge of the adjustment member has downwardly pointing teeth 45 moulded in a recess therein.

12 Once the frame has been fitted in place and the walls built around the frame, the window unit can be fitted therein. The adjustment member 41 with the glazing retaining unit attached thereto is slid into the frame with the base of the adjustment member 41 sliding along the fascia part 20 of the frame, until the seal 44 and the flange 29 engage. The free end of the flange 28 of the metal strip 26 in the frame engages with the teeth in the adjustment member 41 in a ratchet arrangement to prevent the adjustment member 41 from movement in the reverse direction. The weight of the window unit prevents any vertical movement.

With the adjustment member 41 fixed in place, a cill 48 of hollow-cross section may fix to its outer edge. A clip 61 formed in the back edge of the cill 48 engages with the flange 43 protruding from the outer edge of the adjustment member 41. The base of the cill 48 extends horizontally from beyond the outer edge of the outer course of bricks or blocks 10, onto that outer course, up onto the fascia part 20, and then rides up over the upstanding flange 29. The cill 48 is fixed in place with one or more screws 63 which pass from the inner edge of the adjustment member, at a point between the protruding clip 47 and the outwardly pointing flange 46, through the opposite point in the outer edge of the adjustment member and into the back face of the cill at a point below the clip 61. The top face of the cill 48 is angled to steer 13 moisture away from the window frame. The top edge of that face abuts with an edge on the outer f ace of the adjustment member 41, below the bottom edge of the glazing retaining unit 40.

The design of the frame, adjustment member 41 and cill 48 ensures a tortuous path for moisture ingress since any moisture entering at the join between the top of the cill 48 and the outer edge of the adjustment member 41 must traverse the flange 43, and then pass through the seal 44, and moisture entering at the join between the base of the cill 48 and the outer course of blocks or bricks 10 must overcome the upstanding flange 29 before reaching the seal 44.

The outwardly pointing flange 46 on the inner edge of the adjustment member 41 together with the bottom edge of the glazing retention unit 40 form the two edges of a groove, the floor of this groove being provided by the inner edge of the adjustment member 41. An internal window board 62 is cut with a lip in the edge facing the window, and this lip then slots into the aforementioned groove, thereby concealing the cut edges of the board, the adjustment member, and the frame.

-Figure 2 shows a sectional view through the side part of the frame. In this embodiment the outer course of bricks or blocks defines a narrower opening than the -inner course of bricks or blocks. The side part of the frame has a stepped fascia part 70 which extends across 14 the cavity 12, abutting the faces of the brick or block courses facing into the window opening. The step 70a of that stepped fascia part 70 provides a datum for the brick or block course, and so achieves a clean reveal line. In addition its shape conceals the cut edge of any half brick or block that would face towards the stepped fascia part 70. The frame also has a box section part 71 that extends into the cavity and which has a cross section identical to that in the lower part of the frame.

As mentioned earlier an adjustment member 72 is provided along the sides of the frame to secure the glazing retaining unit 40 to the frame. The side cross sections of the adjustment member 72 and the glazing retention unit are the same as the lower cross sections of these parts, and they are joined using the same clip mechanism.

The side adjustment member 72 is secured to the frame using a ratchet arrangement identical to that used to secure the lower portion. A metal strip 76 is held by lips 77 of the facia part 70 and has a projecting flange 78 which engages teeth 79 on the side adjustment member 72. Moreover, a clip 75 on the outer edge of the adjustment member 72 holds a seal 74 which abuts the fascia part 70. Window board or brick plaster board is cut to size to cover the inner course of bricks of blocks, and.the end of this is inserted into the groove formed by the inner pointing flange of the adjustment member and the frame.

Figure 3 shows a sectional view through the top part of the frame/window unit assembly. This figure shows that the upper part 90 of the frame is of hollow box section.

In the construction of a window according to this embodiment, the inner and outer courses of bricks or blocks are built up to cill level and the lower part of the frame positioned over those brick or block courses.

At this stage the rest of the frame is supported by some suitable temporary means. the construction of the brick or block courses continues up the sides of the frame, up to the height of the frame. The temporary frame support is now removed, as the frame is fully supported through the box-sections 21, 71 extending into the cavity. A is lintel 91 is positioned over the top of the frame resting on the brick or block courses at either side of the frame, and construction continues upwards.

Due to small differences in the height of the mortar courses there will inevitably be a gap 92 between the top of the f rame 90 and the underside of the lintel 91. this gap has traditionally been filled with a liquid sealant, however this requires a second step in the construction process and could be inconvenient if the window is high up. In this embodiment a two-art seal 93 is provided at an outer point on the top of the f rame to seal the gap.

the first part of the seal is a resiliently deformable tref oil shaped piece 94 which acts as a main seal, and 16 the second part is a rigid flap 95 which acts as a trim and secondary seal. The two parts may be co-extruded on a base which has an extrusion on its underside which slides into a lipped recess on the top of the frame, thereby securing the seal to the frame. The rigid flap is hinged at one end about the outer edge of the base.

The base is located along the top of the frame such that the hinge of the flap is positioned at the outer edge for the frame. The unattached part of the flap 95 bears against the lintel, at approximately 45' to the vertical.

This flap 95 provides and aesthetic trim to the top of the frame, and serves as a tougher seal than the resiliently deformable seal 94. The resiliently deformable seal 94 is mounted adjacent to the flap 95.

The top leaf of this seal is in intimate contact with the underside of the lintel, and acts as a seal against moisture and draughts.

The frame has a downwardly pointing, lipped flange 96 positioned towards its outer edge, against which the top of the outer edge of the glazing retaining unit 40 abuts. The top of the glazing retaining unit 40 is maintained in abutment with that flange 96 by means of a ratchet mechanism comprising teeth 97 formed in the lower edge of the frame 90 and a flange 98 which engages with those teeth 97. The flange 98 is attached to the top of the glazing retaining unit 40 by means of a bracket part 99 of the f lange 98 of the outer edge of that unit.

17 A hinged trim 100 is provided on the top of the inner edge of the glazing retaining unit 98 to conceal the gap between the frame 90 and that glazing retaining unit 110. One end of the trim 100 abuts the bottom edge of the f rame 90, and the other end is hinged about a fixing portion 101 which clips into the top of the glazing retaining unit 110.

The inner edge of the frame 90 has a recess therein to receive the cut edge of a sheet of plaster board or window board, thereby providing a neat finish for that board.

Fig 3 also shows that the upper part 90 of the frame has an external opening 112 therein and an internal opening 113 which is coverable by a movable cover 114.

This enables ventilation by opening the cover 114 and so providing an air path from the outside to the inside via openings 112 and 113.

The upper part 90 of the frame shown in Fig 3 must be joined to the sides of the frame shown in Fig 2.

Preferably, this is done by a joining member which has projections which are received in hollow openings 115, 116 of the top part 90 and the box section part 71 of the sides of the frame.

Fig 4 shows one example of such a joining member which can be used with the frame described previously. The joining member has a block 120 having a first projection 121 extending therefrom and a second 18 projection 122 also extending therefrom in a direction perpendicular to the first projection 121. Each projection 121 has ribs 123, 124 thereon. The projection 121 is inserted into the hollow box section 71 of the side of the frame shown in Fig 2, and the ribs 12-3 engage the inner surface of that hollow box section 71 adjacent the metal strips 76, thereby securing the block 120 to the hole formed by the box section 71. In a similar way, the second projection 122 projects into the hollow interior of the upper part 90, with the ribs 124 engaging the sides of that hollow part 90. Moreover, as shown in Fig 4, a plate 125 is provided at the junction of the projection 122 and block 120, which plate 125 conforms to the shape of the end of that part 90. The plate 125 thus acts as a closure for the hollow interior 115 of that part 90. Preferably, the plate 125 is received into the end of the hollow part 90. This prevents insects entering the interior 115 from the cavity between the inner and outer courses 10, 11 of bricks/blocks.

Fig 5 shows a modification of the joining member of Fig 4. In the arrangement of Fig 4, block 120 and the projections 121, 122 are integral. In the arrangement of Fig 5, on the other hand, they are separate to enable adjustment. Thus, the block 120 has lips 130 defining a slot 131 and the projection 121 has a bracket part 132 which is sideably received in the slot 131. The relative positions of the block 120 and the projection 121 are 19 then adjustable in the direction of arrow A by sliding the bracket 132 in the slot 131. Opening 133 is then provided in the block 120, which receives a screw 134 which also engages a bore 135 in the projection 121.

When the screw is screwed into the bore 135, the head of the screw 134 clamps the projection 121 in place relative to the block 120.

Furthermore, the block 120 has a bracket 136 which fits into a slot 137 in the projection 122, thereby enabling the two to be fitted together. As shown in Fig 5, the slot 137 has a profiled shape so that the bracket 136 may be inserted into one of a plurality of different positions in the slot 137, thereby permitting adjustment of the relative positions of the block 120 and projection 122 in the direction of arrow B. Many variations on the embodiment described above are possible. Fig 6 shows variations on the structure shown in Fig 1. In Fig 6, components which correspond to components of Fig 1 are indicated by the same reference numerals, although not all reference numerals are shown for the sake of clarity.

In Fig 6, the adjustment member 140 has a different shape from the adjustment member 41 in Fig 1. Rather than having a flange 46 which receives part of the internal window board 62, it has a profiled part 141 which, together with the glazing retaining unit 40, receives the lip of the internal window board 62. The outer side of the adjustment member 140 has a similar profile 142 which conforms to a lip 143 of the cill 144.

The cill 144 and the adjustment member 140 have corrugated surfaces 145, 146 which engage, to prevent movement of the cill 144 relative to the adjustment member 143.

Fig 6 also shows that the adjustment member 41 has a co-extruded seal 147 which abuts against the flange 29 and thus replaces the seal 44 in Fig 1. Finally, the lower surface 148 of the adjustment member conforms more closely to the facia part 20 of the frame, thereby depressing the upstanding flange 29 of the strip 26.

Fig 7 illustrates a modification of the part of the frame shown in Fig 3. Again, corresponding parts are indicated by the same reference numerals, although not all reference numerals are shown for the sake of clarity.

The arrangement shown in Fig 7 differs from that of Fig 3, in that it does not use a co-extruded piece to form the seals 94, 95. Instead, the pivoting seal 150, corresponding to the seal 95 in Fig 3, is integral with the top part 90 of the frame, whereas the deformable seal 151, corresponds to the seal 94 in Fig 3, is separate and mounted on the top part 90 of the frame by a suitable bracket 152.

21

Claims

CLAIMS 1. A window frame mounted in a building with a lintel extending

over the frame, wherein the frame is sealed to the lintel by a seal having two parts, the first part being a resiliently deformable part attached to the frame or lintel and abutting against the lintel or frame in a sealing manner, and the second part being a pivoting flap hinged to the frame or lintel and bearing against the lintel or frame, thereby to close the gap between the lintel and the frame. 2. A frame according to claim 1, wherein the two parts of the seal form a unitary element. 3. A frame according to claim 1 or claim 2 wherein the first part of the seal has a cross-section being a hollow trefoil. 4. A frame according to any one of claims 1 to 3 wherein the seal is attached to the frame. 5. A window frame for mounting in a building with a lintel extending over the frame, wherein the frame is sealable to the lintel by a seal having two parts, the first part being a resiliently deformable part attached to the frame for abutting against the lintel in a sealing manner, and the second part being a pivoting flap hinged to 'the frame and being arranged to bear against the frame, for closing the gap between the lintel and the frame.

22 6. A window unit mounted in a frame, the frame having a part forming a closure for the cavity of a cavity wall, which part has at least one clip mounted in a recess therein, the or each clip including an upstanding flange 5 engaging a ratchet on the window unit. 7. A unit according to claim 6 having a profiled strip forming said clip or clips. 8. A window unit mounted in a f rame, the window unit having a hinged trim piece thereon extending along an upper surface thereof, the trim piece being biased to bear against the frame to seal the window unit to the frame.

9. A window unit for mounting is a frame, the window unit having a hinged trim piece thereon extending along a surface thereof, the trim piece being biased for bearing against the frame for sealing the window unit to the frame. 10. A window frame unit mounted in a frame, the frame having a part forming a closure for the cavity of a cavity wall, which part has an upstanding flange arranged to project away from the cavity, the window or door unit having a deformable seal thereon abutting the flange. 11. A unit according to claim 10 wherein a cill piece having a part extending outwardly of the plane of the frame unit has a part extending over said flange and seal and engaging the unit.

23 12. A window unit mounted in a frame, wherein the unit includes a detachable rigid adjustment member on at least one side thereof such that the outer periphery of the unit conforms to the inner periphery of the frame.

13. A unit according to claim 12 having adjustment members on three sides of said link. 14. A unit according to claim 12 or claim 13, wherein a cill piece having a part extending outwardly of the plane of the unit has a part engaging the one of the said adjustment members. 15. A window unit having a cill piece mounted thereon, the cill piece having a part extending outwardly of the plane of the unit being separable from the unit and being secured thereto by a securing member passing through said unit. 16. A window unit mounted in a wall, wherein the unit has a groove or recess in an inside surface thereof, which groove or recess receives the edge of a panel covering the material of the wall.

17. A unit according to claim 16, mounted in a f rame wherein the unit includes a detachable adjustment member on at least one side thereof such that the outer periphery of the unit conforms to the inner periphery of the frame.

18. A unit according to claim 16 or claim 17 wherein the groove or recess is between a flange on the adjustment 24 member and the adjacent panel of the rest of the window unit. 19. A window unit for mounting in a wall, wherein the unit has a groove or recess in an inside surface thereof, which groove or recess receives the edge of a panel covering the material of the wall. 20. A window frame mounted in a cavity wall of a building, the frame having a part forming the closure for the cavity of the cavity wall and a part extending into the cavity, the part extruding with the cavity having projecting legs which legs rest on a inner surface of the cavity. 21. A window frame according to claim 20, wherein the part extending into the cavity is of box section.

22. A window frame for mounting in a cavity wall of a building, the frame having a part arranged to form a closure for the cavity of the cavity wall and a part extending into the cavity, the part extending with the cavity having projecting legs which legs are arranged to rest on a inner surface of the cavity. 23. A window frame comprising a plurality of box sections interconnected by joining pieces, wherein the joining pieces have projecting parts which fit into corresponding openings in the ends of the box sections, the projection parts closing said openings.

24. A frame according to claim 23, wherein at least one of the joining pieces in adjustable to vary the separation of the box sections which it joins.