EP4536916A1

EP4536916A1 - Fastening system for a façade element and method for fastening in the case of a projecting floor slab

Info

Publication number: EP4536916A1
Application number: EP23731632.8A
Authority: EP
Inventors: Michael Langkau
Original assignee: Saint Gobain Isover; Saint Gobain Isover SA France
Current assignee: Saint Gobain Isover; Saint Gobain Isover SA France
Priority date: 2022-06-09
Filing date: 2023-06-07
Publication date: 2025-04-16
Also published as: WO2023237625A1

Abstract

The invention relates to a fastening system (2) for a façade element (4) for connecting to an existing façade (2) with a projecting floor slab (62), wherein the fastening system (2) comprises two components (10, 20), wherein a first component (10) comprises at least one first dead weight anchor (12) for fastening to the existing façade (6) and at least one second dead weight anchor (14) for fastening to the façade element (4) and wherein the second component (20) comprises at least one wind load anchor (22) for fastening to the existing façade (6) and to the façade element (4). Provision is made that the first component (10) is configured to introduce substantially a weight of the façade element (4) into the existing façade (6), and the second component (20) is configured to introduce substantially a wind suction load and wind pressure load into the existing façade (6). Further aspects of the invention relate to a use of the fastening system (2) and methods for fastening a façade element (4) to an existing façade (6) by means of the fastening system (2), a façade and a method for the refurbishment of an existing façade (6) to increase energy efficiency.

Description

FIELD OF THE INVENTION

The invention relates to a fastening system for a fagade element for connecting to an existing fagade with a projecting floor slab. Further aspects of the invention relate to methods for fastening a fagade element to an existing fagade, a fagade and a method for the refurbishment of an existing fagade to increase energy efficiency.

PRIOR ART

EP 3 808 553 A1 discloses a fagade element and a method for the refurbishment of buildings to increase energy efficiency, wherein the fagade element has a high degree of prefabrication. The fagade element comprises a first insulating element which is arranged in a wooden frame. The insulating element with the wooden frame is encapsulated on the one hand by a solid board, e.g. an OSB, and on the other hand by e.g. a cement-bonded second solid board. Provided on the rear side of the first solid board is a connection layer for connecting to the existing fagade, fastened with a second insulating material layer and first connectors. When installing the fagade element on the existing fagade, the existing fagade is first provided with second connectors and the prefabricated fagade element is fastened to the existing fagade by means of the first and second connectors. The connectors are suitable to form a connection with one another guaranteeing tensile strength and are designed to introduce the load of the fagade element into the existing fagade.

A disadvantage of the connectors disclosed in EP 3 808 553 A1 is that in the case of heavy fagade elements and also e.g. masonry substrates, a large number of connectors must be used by reason of the introduction of weight into the existing fagade, which makes refurbishment to increase energy efficiency expensive. Also, the fastening system is not suitable for connecting to existing fagades having a projecting floor slab.

DE 34 19 457 A1 discloses a curtain wall consisting of thin concrete slabs having a thickness of between 5 and 10 cm and a storey-spanning length, in particular in the range between 9 and 11 m. These concrete slabs are suspended from a supporting frame consisting of bearing walls and ground plates or floor plates by means of anchor elements which are embedded in the concrete slabs on the one hand and in the bearing walls on the other hand. In order to avoid wobble movements in the wind, the concrete slabs are additionally connected to further ground plates or floor plates at their base and, where appropriate, at an intermediate height with the aid of further fastening anchors which form loose bearings, wherein the further fastening anchors are likewise embedded in the concrete slabs and ground plates or floor plates.

A disadvantage of the system described in DE 34 19 457 A1 is the high degree of prefabrication by reason of the embedding of the fastening anchors and the inadequate adaptability following therefrom. On an industrial scale, the system is suitable only for new buildings, but not for the refurbishment of old buildings which have a high degree of individuality.

DE 23 44 429 A1 discloses a window balustrade element which is fastened to a floor slab by steel brackets and U-profiles. OBJECT OF THE INVENTION

It is an object of the invention to provide a fastening system for a fagade element which is suitable for connecting to existing fagades consisting of concrete, masonry or wood and having a projecting floor slab.

A further object of the invention is to provide an adaptable fastening system which also manages in particular with fewer connectors. Furthermore, the fastening system is to be designed to be three-dimensionally adjustable after positioning of the fagade element on the existing fagade.

It should also be possible to design the fastening system adaptively for different applications, in particular adaptively in relation to the weight of the fagade elements and wind suction and wind pressure loads.

Finally, the fastening system should also comprise as few individual parts as possible in order to enable production in large quantities in a cost-effective manner and to keep installation complexity low.

DISCLOSURE OF THE INVENTION

A fastening system in accordance with the invention for a fagade element for connecting to an existing fagade having a projecting floor slab comprises two different components, wherein a first component comprises at least one first dead weight anchor for fastening to the projecting floor slab of the existing fagade and at least one second dead weight anchor for fastening to the fagade element, wherein in each case a first and a second dead weight anchor can be connected to one another by fastening means, and wherein the second component comprises at least one wind load anchor for fastening to the projecting floor slab of the existing fagade and to the fagade element. Provision is made that at least the second dead weight anchor and/or the wind load anchor are designed to be fastened to the fagade element, in particular to wooden frame elements of the fagade element, by dowelling, nailing, screwing and/or hooking. For example, the second dead weight anchor and the wind load anchor can have circular holes or elongate holes which are suitable for this purpose. Furthermore, in preferred embodiments provision is made that the wind load anchor is designed to be fastened to the projecting floor of the existing fagade by dowelling, nailing, screwing and/or hooking. For example, the wind load anchor can have circular holes or elongate holes which are suitable for this purpose.

The fastening system can comprise, in terms of a set, the fastening means for dowelling, nailing, screwing and/or hooking the second dead weight anchor and the wind load anchor to the fagade element.

The fastening system can comprise the fastening means for connecting the dead weight anchors.

In an advantageous manner, the installation point and number of anchors and fastening means are not specified and can be adjusted adaptively, in advantageous embodiments even on the building site.

In accordance with the invention, provision is additionally made that the first component is configured to introduce substantially a weight of the fagade element into the existing fagade, and that the second component is configured to introduce substantially a wind suction load and wind pressure load into the existing fagade.

A floor slab is described as "projecting" within the context of the present disclosure if the floor slab projects beyond a front face of the existing fagade, e.g., by a few centimetres to 50 cm. The fastening system is particularly well suited for projecting floor slabs with projections or overhangs in the range of 10 cm to 30 cm.

The fastening system in accordance with the invention supplements fastening systems for fagade elements which are mounted on parts of the existing fagade without projections of the floor slab. When refurbishing an existing fagade as described in EP 3 808 553 A1 , the fastening system in accordance with the invention is considered typically for the uppermost row of fagade elements and in particular if the uppermost floor slab is formed so as to project. However, the system in accordance with the invention can naturally also be used in the case of intermediate floor slabs if, for whatever reasons, they are formed so as to project with respect to the front face of the fagade wall.

Splitting the fastening system into first and second components with different functions makes possible an adaptive solution for different applications. Depending upon the weight of the fagade element, more or less first and second dead weight anchors which form the first component can be provided in the fastening system. Moreover, in dependence upon the required securing in relation to wind suction and securing in relation to wind pressure, more or less wind load anchors which form the second component can be provided in the fastening system. By dividing the tasks of the first and second components, the overall system is more favourable than a system, in which the connectors have both functionalities, since, in general, the number of wind suction and wind pressure anchors required is the predominant factor.

For a given fagade element, in each case at least two first and second dead weight anchors are preferably provided in order to fasten the fagade element at the top two corners in each case. Depending upon the weight, further first and second dead weight anchors can be used, preferably always at the same spaced interval therebetween, e.g. always at a spaced interval of 1 m to 3 m. More or less interspersed wind load anchors can be provided, wherein the number thereof can be adapted depending upon the wind suction load and wind pressure load.

The first component is configured to introduce substantially a weight of the fagade element into the existing fagade. "Substantially" is understood to mean that at least 70%, preferably at least 80% and further preferably at least 90%, of the weight of the fagade element is introduced into the existing fagade via the first component. Furthermore, the first component can partially absorb wind suction and wind pressure loads, wherein this accounts preferably for no more than 30%, more preferably no more than 20%, and even more preferably no more than 10%. The second component is configured to introduce substantially a wind suction load and wind pressure load into the existing fagade. Again, "substantially" is understood to mean that the second component introduces at least 70%, preferably at least 80% and further preferably at least 90%, of the wind suction load and wind pressure load into the existing fagade. Furthermore, the second component can introduce a part of the weight of the fagade element into the existing fagade, wherein this part accounts for no more than 30%, preferably no more than 20%, and even more preferably no more than 10%, of the weight of the fagade element.

According to one embodiment, the first dead weight anchor comprises at least one first flat piece for lying against the projecting floor slab.

For instance, the first flat piece can be a two-dimensional member but alternatively and preferably can also be formed by means of a web portion of a profile piece. In particular, a U-profile or C-profile is provided in this case, as well as alternatively a base portion of a cup-shaped member. In this context, the profile pieces comprise not only the flat piece, which comes to lie against the projecting floor slab, but also lateral flange portions or circumferential cup portions. These can be provided, for instance, for stability reasons to prevent deflection of the flat piece or even to counteract a risk of injury caused by fastening means which stick out and protrude.

The fastening means preferably comprise here and hereinafter a threaded rod and a lock nut, but alternatively can also be designed as a machine screw having a screw head, e.g. in the countersunk head profile or flat head profile.

Preferably, the first dead weight anchor comprises at least one, more preferably two or three second through-openings, which are designed in particular as threaded bores, for receiving the fastening means, in particular the threaded rod or the machine screw. In particular, the first flat piece can be provided with one or a plurality of drill holes with or without a thread in order to permit the passage of the fastening means and the corresponding anchoring of the threaded rod or screw in the projecting floor slab.

In order to receive the fastening means, in particular the threaded rod or machine screw, the second dead weight anchor likewise comprises a corresponding second through-opening. In particular, the through-opening of the second dead weight anchor can be provided with one or a plurality of drill holes with a thread in order to permit the passage of the fastening means and the corresponding anchoring of the threaded rod or screw in the second dead weight anchor.

Furthermore, the second dead weight anchor comprises preferably at least one second flat piece for lying against and anchoring to the fagade element. The second flat piece is provided with a row of drill holes without a thread in order to permit corresponding anchoring in the fagade element. Instead of providing a flat piece, it is also possible to provide a profile piece, e.g. a U-profile or a C-profile. The counterpiece on the fagade element is typically a solid board, e.g. an OSB, or a wooden frame element, but can also comprise e.g. metal struts, as described in EP 3 808 553 A1.

The wind load anchor comprises preferably at least one bridge piece, wherein this can be formed by means of a two-dimensional member or by means of a web region of a profile piece, e.g. a U-profile or a C-profile. The wind load anchor comprises at least one, preferably at least two, fastening flanges which are fastened to the bridge piece or are formed in one piece therewith. The fastening flanges can be e.g. welded to the bridge piece.

According to one advantageous embodiment, after fastening the dead weight anchors and the wind load anchors, the second flat piece is aligned perpendicularly with the bridge piece. Since the wind suction load and pressure load are introduced into the existing fagade in each case via the second flat piece and via the bridge piece respectively, this arrangement has the advantage of a long-lasting and stable connection.

In preferred embodiments, the dead weight and wind load anchors are designed as metal formed parts, in particular e.g. as steel profiles, in particular galvanised steel profiles. Alternatively, dead weight anchors and wind load anchors which are manufactured from synthetic material, in particular from fibre-reinforced synthetic materials, can be provided, wherein this is more likely to be advantageous in the case of lightweight fagade elements. In accordance with the invention, the use of one of the described fastening systems for connecting a fagade element to an existing fagade having a projecting floor slab is proposed. The use of the described fastening systems is particularly advantageous in the case of prefabricated fagade elements, in particular those which have wooden frame elements.

According to a further aspect, the invention comprises a method for fastening a fagade element to an existing fagade having a projecting floor slab, in particular to the projecting floor slab of the existing fagade, by means of one of the described fastening systems.

In an advantageous manner, the fagade element can be pre-assembled with the second dead weight anchors in a factory. In particular, the second dead weight anchors can be fastened e.g. to wooden frame elements of the fagade element or to solid boards of the fagade element, e.g. with screws, hooks, nails or the like. The production of the fagade elements as part of a prefabrication procedure in the factory reduces the inconvenience for the residents of the building with the existing fagade.

In a first step of the method, first through-openings are made in the region of the projection of the floor slab of the existing fagade, e.g. by drilling, and the first dead weight anchors are attached to the existing fagade by inserting the fastening means into the first through-openings.

In a second step, the first and second dead weight anchors are connected to one another by means of the fastening means. The load of the fagade element is absorbed by the existing fagade, more precisely by the floor slab.

In a third step, the wind load anchors are connected to the floor slab, preferably in the region of the projection, and to the fagade element.

Alternatively, the wind load anchors can be attached to the floor slab before the dead weight anchors are connected to one another. In the third step, the wind load anchors are then connected to the fagade element. According to a preferred embodiment, more wind load anchors are used than dead weight anchors in both possible variants of the methods when fastening the fagade element to the existing fagade. For example, for a given fagade element, dead weight anchors are attached merely to the top two corners of the fagade element and further second dead weight anchors are attached therebetween if the weight of the fagade element requires this. One wind load anchor can be attached between each of the second dead weight anchors, but also e.g. in each case more than one wind load anchor between every two second dead weight anchors. It has been shown that preferably at least twice as many wind load anchors can be used as dead weight anchors. Therefore, in a preferred embodiment, provision is made that the number of wind load anchors is 1.5 to 3 times the number of dead weight anchors per fagade element.

In both possible variants of the methods, provision can advantageously be made that the fagade element is adjusted in relation to its position and/or inclination with respect to the existing fagade. The adjustment can be effected in particular by manipulating the fastening means.

With the measures of the invention, complete 3D fine-positioning of the fagade element in relation to the existing fagade is possible.

The height of the fagade element can be adjusted by manipulating the fastening means of the dead weight anchors. When using a plurality of first and second dead weight anchors, the inclination of the fagade element can be adjusted in the plane of the existing fagade by manipulating the fastening means differently. The adjustment is effected in an expedient manner when the first and second dead weight anchors are being connected by means of the first fastening means.

According to a further aspect, a fagade comprises an existing fagade and a fagade element fastened by means of one of the described fastening systems, preferably a plurality of fagade elements fastened in this manner.

In the case of a method for the refurbishment - to increase energy efficiency - of an existing fagade having a projecting floor slab, this can be examined initially in relation to the expected wind load. Starting from the ascertained wind suction load and wind pressure load and in dependence upon the size and/or number of fagade elements, the number of wind load anchors and/or the ratio of the number of dead weight anchors to wind load anchors can be determined. In dependence upon the thus determined numbers of dead weight anchors and wind load anchors, the size and/or number of fagade elements can be optimised and/or the positions of the dead weight anchors and wind load anchors on the existing fagade and on the fagade elements can be distributed in an optimised manner.

The fagade elements are installed preferably by means of a crane or a lifting platform as described above. In an advantageous manner, the fastening system allows installation without erecting scaffolding and provides for easy removal.

BRIEF DESCRIPTION OF THE FIGURES

Further preferred embodiments of the invention are described in detail hereinafter with reference to the figures. In the drawing:

Figure 1 shows a side sectional view of an existing fagade with a fagade element fastened thereto, according to one embodiment of the invention,

Figure 2 shows a further side sectional view of the existing fagade with the fagade element of figure 1 fastened thereto, but in another sectional plane,

Figure 3A shows a front view of a second dead weight anchor according to one embodiment of the invention,

Figure 3B shows a side view of the second dead weight anchor of figure 3A, Figure 3C shows a plan view of the second dead weight anchor of figure 3A, and Figure 4 shows a perspective view of a fagade element which is connected to an existing fagade by means of a second component, according to one embodiment of the invention,

EMBODIMENTS OF THE INVENTION Like components or components acting in an identical manner are designated hereinafter by like reference signs. The description of these members will not be repeated hereinafter.

Here and hereinafter, vertical direction is generally understood to be an orientation along the surface of the existing fagade and horizontal direction is understood to be a direction extending perpendicularly to the surface of the existing fagade, related to typical house construction. In this sense, the projection of the projecting floor slab extends typically, but in a manner not limiting for the invention, in a horizontal direction.

Figure 1 shows a side sectional view of an existing fagade 6 with a fagade element 4 fastened thereto and a first component 10 of a fastening system 2 according to one embodiment of the invention.

Figure 2 shows a further side sectional view of the existing fagade 6 of figure 1 , but at a different height in relation to the plane of the drawing than in figure 1. Figure 2 illustrates a sectional view of the existing fagade 6 with the fagade element 4 fastened thereto and a second component 20 of the fastening system 2 in accordance with the invention.

The existing fagade 6 in figure 1 comprises a wall 60 with a floor slab 62 arranged thereon which has a projection 64. In the region of the projection 64, the floor slab 62 projects beyond the wall 60.

Provided in the floor slab 62 in the region of the projection 64 is a first through-opening 66 which has been introduced into the floor slab 62 e.g. by means of a core drill. The first through-opening 66 is provided to receive a threaded rod 16 and is produced having a larger diameter of e.g. 20 to 50 mm in order to provide a certain amount of adjustability. A machine screw can also be used instead of the threaded rod 16.

The first component 10 of the fastening system 2 comprises a first dead weight anchor 12 which, in the illustrated embodiment, is formed for example, but in a manner not limiting for the invention, from a U-profile. The U-profile comprises a first flat piece 120, which is designed to lie against the projecting floor slab 62, and two lateral flange portions 122. A second through-opening 124 is formed in the region of the first flat piece 120. The threaded rod 16 pushes through the second through-opening 124 and through the first through-opening 66 and is fixed at the top by a lock nut 18. The threaded rod 16 and the lock nut 18 are also designated as fastening means 16, 18. The first dead weight anchor 12 is connected via the fastening means 16, 18 to a second dead weight anchor 14 which is fastened to the fagade element 4.

The fagade element 4 can be designed substantially as described in EP 3 808 553 A1 and in this case comprises for example and preferably a wooden frame 40 in which e.g. insulating material is arranged. The wooden frame 40 is closed on both sides with solid boards, e.g. an OSB on one side and a cement-bonded solid board (not illustrated) on the other side, wherein the second dead weight anchor 14 can then be fastened directly to the OSB or to the wooden frame 40. In contrast to the fagade element described in EP 3 808 553 A1 , the fagade element 4 is provided with a fore-part specifically for the projecting floor slab 62 in the region of the connection to the projection 64, in this case for example, but in a manner not limiting for the invention, comprising two fore-part beams 42 and an insulation layer 44 located between the fore-part beams 42 and the floor slab 62.

The second dead weight anchor 14 is described in greater detail with reference to figures 3A, 3B, 3C.

Figure 2 shows the system of figure 1 in another sectional plane, illustrating the second component 20 of the fastening system 2. Generally, the first component 10 and the second component 20 are not provided at the same height, wherein the term "height" refers in this case to the position on the plane of the drawing or sectional plane.

The second component 20 comprises a wind load anchor 22 which has at least one bridge piece 220 and in this case comprises by way of example and preferably 4 fastening flanges 222 (cf. figure 4). The wind load anchor 22 is connected, e.g. nailed or screwed, in the region of the fastening flanges 222 via fastening means on the one hand to the fore-part beam 42 and on the other hand to the floor slab 62, in this case advantageously but in a manner not limiting for the invention, in the region of the projection 64. The wind load anchor 22 is illustrated and described in greater detail with reference to figure 4.

The first component 10 of the fastening system 2 illustrated in figure 1 is suitable for transferring substantially the weight of the fagade element 4 into the existing fagade 6, in particular via the floor slab 62. Wind loads are introduced into the existing fagade 6, in particular into the floor slab 62 substantially by means of the wind anchor 22 illustrated in figure 2.

Figure 3A shows the second dead weight anchor 14 according to one embodiment of the invention. The second dead weight anchor 14 comprises a second flat piece 140 which comes to lie against the fagade element 4 (not illustrated). As illustrated in figure 3B, the flat piece 140 is designed as a two-dimensional member, which, however, is not limiting for the invention. As an alternative to the two-dimensional design, the flat piece 140 can also be a web region of a profile piece (not illustrated), e.g. a C-profile or a U-profile. After installation, the central web of the profile piece lies against the fagade element 4, the outer flanges extend preferably away from the fagade element 4 in the direction of the existing fagade 6.

Figure 3A shows on the flat piece 140 a row of third through-openings 142 which can be designed e.g. as circular holes. The second dead weight anchor 14 is fastened to the fagade element 4 via the third through-openings 142. The size of the third through- openings 142 can vary and is tailored to the weight of the fagade element 4. Instead of circular holes, elongate holes can be provided in order to be able to screw in the fastening means, e.g. countersunk head screws, into the fagade element 4 at a variable angle, i.e. at a 90° angle or at an angle different from 90°. A non-orthogonal screw connection may be required due to the material thickness of the fagade element 4. In an advantageous manner, e.g. an angle disk can be used in order to provide an angled support for a countersunk head screw which can then be screwed through the elongate hole of the second dead weight anchor 14 and the fagade element 4 at an angle defined by the angle disk.

In the upper region, the second dead weight anchor 14 comprises a transverse web 144 which is arranged spaced apart from the second flat piece 140 via a spacer 148. As can be seen in figure 3C, the transverse web 144 comprises a second through- opening 124 which, corresponding to the second through-opening 124 in the first dead weight anchor 12, is tailored to the size of the threaded rod 16.

In the illustrated exemplified embodiment, the spacer 148 is designed by way of example but in a manner not limiting for the invention, in the form of a U-profile open at the top. A longitudinal axis of the transverse web 144 extends perpendicularly to a longitudinal axis of the flat piece 140 and perpendicularly to a longitudinal axis of the U-profile or spacer 148. The transverse web 144 has fastening flanges which protrude laterally over the spacer 148 and the flat piece 140. Threaded bores 146 are provided on the transverse web 144, in particular on its fastening flanges, which will not be discussed in greater detail within the scope of the present invention.

Figure 4 shows the wind load anchor 22 of the second component 20 of the fastening system 2 in a perspective view. The wind load anchor 22 comprises the bridge piece 220 which bridges the space between the floor slab 62 of the existing fagade 6 and the fagade element 4. In the region of the floor slab 62, in particular in the region of the projection 64, the wind load anchor 22 is fastened with the aid of its four fastening flanges 222, as illustrated with reference to figure 2, in this case in an exemplified but not limiting manner. In the region of the fastening flanges 222, the wind load anchor 22 has corresponding third through-openings 142 for receiving suitable fastening means, such as e.g. screws or nails.

The invention is not limited to the exemplified embodiments described herein. On the contrary, a large number of modifications are apparent to a person skilled in the art within the scope of the claims.

REFERENCE SIGNS

2 fastening system; 4 fagade element; 40 wooden frame; 42 fore-part beam; 44 insulation layer; 6 existing fagade; 60 wall; 62 floor slab; 64 projection; 66 first through- opening; 10 first component; 12 first dead weight anchor; 120 first flat piece; 122 flange portion; 124 second through-opening; 14 second dead weight anchor; 140 second flat piece; 142 third through-opening; 144 transverse web; 146 threaded bore; 148 spacer; 16 threaded rod; 18 lock nut; 20 second component; 22 wind load anchor; 220 bridge piece; 222 fastening flange

Claims

1. Fastening system (2) for a fagade element (4) for connecting to an existing fagade (6) with a projecting floor slab (62), wherein the fastening system (2) comprises two components (10, 20), wherein a first component (10) comprises at least one first dead weight anchor (12) for fastening to the projecting floor slab (62) of the existing fagade (6) and at least one second dead weight anchor (14) for fastening to the fagade element (4), wherein a first and a second dead weight anchor (12, 14) can each be connected to one another by means of fastening means (16, 18), and wherein the second component (20) comprises at least one wind load anchor (22) for fastening to the existing fagade (6) and to the fagade element (4), wherein the first component (10) is configured to introduce substantially a weight of the fagade element (4) into the projecting floor slab (62) of the existing fagade (6), and the second component (20) is configured to introduce substantially a wind suction load and wind pressure load into the existing fagade (6).

2. Fastening system (2) as claimed in claim 1 , characterised in that at least the second dead weight anchor (14) and/or the wind load anchor (22) are designed to be fastened to the fagade element (4), in particular to wooden frame elements of the fagade element (4), by dowelling, nailing, screwing and/or hooking.

3. Fastening system (2) as claimed in any one of the preceding claims, characterised in that the fastening system (2) comprises fastening means for dowelling, screwing and/or hooking the second dead weight anchor (14) and/or the wind load anchor (22) to the fagade element (4).

4. Fastening system (2) as claimed in any one of the preceding claims, characterised in that the fastening system (2) comprises fastening means for connecting the dead weight anchors (12, 14).

5. Fastening system (2) as claimed in any one of the preceding claims, characterised in that the first dead weight anchor (12) has a first flat piece (120) for lying against the projecting floor slab (62).

6. Fastening system (2) as claimed in claim 5, characterised in that the first flat piece (120) is formed by means of a web portion of a profile piece, in particular a U-profile or C-profile or by means of a base portion of a cup part.

7. Fastening system (2) as claimed in any one of the preceding claims, characterised in that the fastening means (16, 18) comprise a threaded rod (16) and a lock nut (18) or a machine screw.

8. Fastening system (2) as claimed in claim 7, characterised in that the first dead weight anchor (12) comprises at least one, preferably two or three second through-openings (124) - designed in particular as threaded bores - for receiving the threaded rod (16) or machine screw.

9. Fastening system (2) as claimed in any one of the preceding claims, characterised in that the second dead weight anchor (14) comprises at least one second flat piece or profile piece (140) for lying against and anchoring to the fagade element (4).

10. Fastening system (2) as claimed in any one of the preceding claims, characterised in that the wind load anchor (22) comprises at least one bridge piece (220) having fastening flanges (222) for lying against and anchoring to the existing fagade (6) and the fagade element (4).

11. Fastening system (2) as claimed in claims 9 and 10, characterised in that after fastening the dead weight anchors (12, 14) and the wind load anchors (22), the second flat piece (140) is oriented perpendicularly to the bridge piece (220).

12. Use of a fastening system (2) for connecting a fagade element (4) to an existing fagade (6) with a projecting floor slab (62), wherein the fastening system (2) is characterised by the features of any one of the preceding claims.

13. Method for fastening a fagade element (4) to an existing fagade (6) with a projecting floor slab (62) by means of a fastening system (2), wherein the fastening system (2) is characterised by the features of any one of the preceding claims 1 to 11 , comprising the steps of:

- attaching second dead weight anchors (14) to the fagade element (4), in particular by dowelling, nailing, screwing and/or hooking the second dead weight anchors (14) to wooden frame elements (40) of the fagade element (4), in particular for producing a prefabricated fagade element (4),

- providing first through-openings (66) in the region of the projection (64) of the floor slab (62) of the existing fagade (6) and attaching the first dead weight anchors (12) to the existing fagade (6) by inserting the fastening means (16, 18) into the first through-openings (66),

- connecting the first and second dead weight anchors (12, 14) by means of the fastening means (16, 18), wherein the load of the fagade element (4) is absorbed by the existing fagade (6),

- connecting wind load anchors (22) to the floor slab (62), preferably in the region of the projection (64), and to the fagade element (4).

14. Method for fastening a fagade element (4) to an existing fagade (6) with a projecting floor slab (62) by means of a fastening system (2), wherein the fastening system (2) is characterised by the features of any one of the preceding claims 1 to 11 , comprising the steps of:

- providing first through-openings (66) in the region of the projection (64) of the floor slab (62) of the existing fagade (6) and attaching the first dead weight anchors (12) to the existing fagade (6) by inserting the fastening means (16, 18) into the first through-openings (66), - attaching wind load anchors (22) to the floor slab (62), preferably in the region of the projection (64),

- connecting the wind load anchors (22) to the fagade element (4).

15. Method as claimed in claim 13 or 14, characterised in that more wind load anchors (22) are used than dead weight anchors (12, 14), in particular that the number of wind load anchors (22) is 1.5 times to 3 times the number of dead weight anchors (12, 14) per fagade element (4).

16. Method as claimed in any one of claims 13 to 15, characterised in that the fagade element (4) is adjusted in relation to its position and/or inclination with respect to the existing fagade (6).

17. Fagade having a fagade element (4) which is fastened to an existing fagade (6) with a projecting floor slab (62) by means of a fastening system (2), wherein the fastening system (2) is characterised by the features of any one of the preceding claims 1 to 12.

18. Method for the refurbishment - to increase energy efficiency - of an existing fagade (6) with a projecting floor slab (62), comprising the steps of:

- determining a wind suction load and wind pressure load on the existing fagade (6);

- determining the number of wind load anchors (22) or determining the ratio of the number of dead weight anchors (12, 14) to wind load anchors (22) in dependence upon the determined wind suction load and wind pressure load and upon the size of the fagade elements (4);

- optimising the size of the fagade elements (4) and/or the distribution of the positions of the dead weight anchors and wind load anchors (12, 14, 22) on the existing fagade (6) and on the fagade elements (4) in dependence upon the number thereof;

- fastening the fagade elements (4) in the region of the projecting floor slab (62) according to a method as claimed in any one of claims 13-16.