WO2014142739A1

WO2014142739A1 - Roof-wall building element and building structure formed thereof

Info

Publication number: WO2014142739A1
Application number: PCT/SE2014/050309
Authority: WO
Inventors: Marcus NORSTRÖM
Original assignee: Mobile Hangar System Sweden Ab
Priority date: 2013-03-13
Filing date: 2014-03-13
Publication date: 2014-09-18
Also published as: SE1350305A1

Abstract

A roof-wall building element comprising a wall portion (1) and a roof portion (2) angularly disposed with respect to the wall portion (1) and comprising a ridge portion (3), wherein the roof portion (2) comprises means for connecting two roof-wall building elements along their ridge portions (3). The roof-wall building element comprises at least a first bore (7) in a side edge (8) of the roof-wall building and substantially parallel with the surface of the roof-wall building element and at least a second bore (18) adjacent the side edge and substantially perpendicular to the surface of the roof-wall building element. The first bore is adapted to receive alignment means (19; 11) and the second bore is adapted to receive fastening means (20) such that when two roof-wall building elements are brought together side by side, the first bore of the first roof-wall building element is aligned coaxially with the first bore of the second roof-wall building element and the second bores of the first and second roof-wall building elements, respectively, are disposed substantially side by side. The alignment means may extend into the first bores and the fastening means may extend into the second bores in order to rigidly connect the two roof-wall building elements.

Description

ROOF-WALL BUILDING ELEMENT AND BUILDING STRUCTURE FORMED THEREOF

The present invention relates to a roof-wall building element according to the preamble of claim 1 . In a second aspect, the present invention relates to a building structure formed from a plurality of such roof-wall building elements.

Technical Background of the Invention

It has been known for some time use modular units or sections in order to build large self-supporting structures such as tents, hangars or halls. One example is shown in Fig. 1 . This building structure is assembled from a number of individual sections having flanges along their ridge and side portions which are fastened to adjacent sections by means of nuts and bolts. The fastening ensures that the sec- tions are tightly and robustly connected to each other to withstand all types of weather conditions.

However, one disadvantage of this type of construction is that the flanges projecting perpendicularly from the plane of the section make the sections bulky and difficult to transport in a compact manner.

Another drawback associated with the construction known from the prior art is that assembly is time-consuming and laborious because of the number and placement of the bolts. In addition, the sections need to be held upright in place during mounting which requires several persons and/or extra equipment such as ladders, scaffolding etc. Also, attachment of subsequent sections side by side is arduous since at least the roof portions of the side flanges are difficult to reach without placing loads directly on the individual sections. Hence, such a construction is not appropriate for situations where mobility and rapid assembly, as well as de-assembly, by only a few persons is required.

Therefore, there is a need of developing mobile and quickly mountable build- ing structures which are easy to erect whilst providing a robust and weather tight construction. Summary of the invention

The object of the present invention is to provide mobile and quickly mounta- ble building structures which are easy to erect whilst providing a robust and weather tight construction.

This is achieved by a roof-wall building element according to claim 1 , comprising a wall portion and a roof portion angularly disposed with respect to the wall portion and comprising a ridge portion, wherein the roof portion comprises means for connecting two roof-wall building elements along their ridge portions. The roof- wall building element comprises at least a first bore in a side edge of the roof-wall building and substantially parallel with the surface of the roof-wall building element and at least a second bore adjacent the side edge and substantially perpendicular to the surface of the roof-wall building element. Further, the first bore is adapted to receive alignment means and the second bore is adapted to receive fastening means such that when two roof-wall building elements are brought together side by side, the first bore of the first roof-wall building element is aligned coaxially with the first bore of the second roof-wall building element and the second bores of the first and second roof-wall building elements, respectively, are disposed substantially side by side. Further, the alignment means may extend into the first bores and the fastening means may extend into the second bores in order to rigidly con- nect the two roof-wall building elements.

By providing first and second bores in and near the side edge of the roof-wall building element, which bores are adapted to accommodate fastening and/or alignment means, the present invention facilitates attachment of identical roof-wall building elements side by side without requiring projecting flanges as connection surfaces. Instead, the side edges of the roof-wall building elements are brought together by the aid of the alignment means in the first bores for correct placement. Thereafter, fastening means are inserted into the second bores and tensioned to rigidly attach the roof-wall building elements in a robust and weather tight manner.

Hence, the advantage of the roof-wall building element according to the pre- sent invention is two-fold: attachment is facilitated whilst the elements or sections may be made more compact to facilitate stacking and transport to the site of erection of the building structure.

In a preferred embodiment, the fastening means comprises a turnbuckle including two screws and a pair of tightening members connected to the screws and adapted to be inserted into the second bores of the roof-wall building elements. The screws of the turnbuckle or bottlescrew have threads in opposite directions, right-hand and left-hand, and are connected to tightening members of cylindrical shape which are inserted into the second bores of the roof-wall building elements. This provides a simple and quick way of coupling the roof-wall building elements together and regulating the tension to rigidly attach them.

In an alternative embodiment, the diameter of the first bore varies along the longitudinal extension thereof, and the alignment means comprises a dowel having a shape corresponding to the shape of the first bore. Preferably, the diameter of the first bore increases along at least a part of the longitudinal extension thereof in a direction towards the side edge. The varying diameter of the first bore allows for a stronger dowel and facilitates alignment of the dowel with the corresponding first bore of an adjacent roof-wall building element when bringing them together.

In an advantageous embodiment, the first bore is through-going and extend- ing laterally from one side edge of the roof-wall building element to the opposite side edge thereof. Preferably, the alignment means comprises a rod with substantially the same length as the width of the roof-wall building element and comprising threads at its end portions, and a tubular connection member comprising corresponding threads. By providing alignment means extending through each roof-wall building element and having threaded end portions, an additional means for fastening the roof-wall building elements is achieved, making the construction stronger and more robust.

In a further embodiment, the connection member comprises a substantially centrally positioned flange. The flange acts as a spacer element between adjacent building elements and aid in providing the necessary tightening force on each building element.

By providing roof-wall building elements having means for achieving a pivot- able connection along their ridge portions and through-going bores, a robust construction which may easily be mounted and erected by only a few persons is achieved. The pivotable connection means permits opposing building elements to be easily connected ridge to ridge. Similarly, alignment means extending through the through-going bores may additionally secure the building elements side to side. In another preferred embodiment, the roof portion comprises means for pivotably connecting two roof-wall building elements along their ridge portions. Preferably, the pivotable connection means comprise a plurality of tubular units spaced along the ridge portion such that when two roof-wall building elements are brought together to form a self-supporting building structure, the tubular units of the first roof-wall building element fit into the spaces between the tubular units of the second roof-wall building element, and vice versa, to form a piano type hinge. The piano hinge may be secured with the aid of a dowel or rod inserted through the tubular units. This solution allows for a simple manufacturing design which is easy to mount yet sturdy and robust enough to keep two roof-wall building elements together in the self-supporting building structure under pressure of snow loads, heavy rains or strong winds.

In a preferred embodiment, the roof and wall portions are integrally formed as a single unit. This allows for a strong and weather-resistant construction which fa- cilitates manufacture and lowers production costs.

In yet another embodiment, the roof-wall building element is made from a composite material, preferably comprising fibreglass reinforced vinyl ester plastic. Advantageously, it comprises a sandwich construction wherein two layers of composite material, preferably fibreglass reinforced vinyl ester plastic, are interspaced with a spacer material, preferably of Divinycell® type. This provides for a lightweight but robust construction with optimal insulating properties resulting in an energy efficient building structure with low heating or cooling costs. Furthermore, the costs for maintenance of the building structure are low in that the proposed materials are resistant to wear and tear of surrounding weather conditions.

In an advantageous embodiment, the roof-wall building element further comprises para-aramid fibres (e.g. Kevlar® or Twaron®) to provide protection against shrapnel or bullets. Alternatively, the roof-wall building element further comprises solar panels, cables and lighting moulded into the construction. As such, the building structure may become self-sufficient in electrical energy.

In a further embodiment, the surface of the roof-wall building element is substantially plane such that the roof-wall building element is stackable together with a plurality of substantially identical roof-wall building elements. Hence, the roof-wall building elements may be easily transported in a compact manner. In a second aspect, the present invention relates to a building structure comprising a plurality of roof-wall building elements according to any preceding claim mounted together. Brief Description of the Drawings

Fig. 1 shows an explanatory sketch of a building according to the prior art;

Fig. 2 shows an explanatory sketch of a building structure according to a second aspect of the present invention;

Fig. 3 illustrates different perspectives of the building structure in Fig. 2, wherein the roof-wall building elements according to a first aspect of the present invention are visible;

Fig. 4 illustrates a pair of roof-wall building elements according to one embodiment of the present invention in a mounted state;

Fig. 5 shows a close-up view of a pair of roof-wall building elements accord- ing to one embodiment of the present invention prior to mounting;

Fig. 6 illustrates a pair of roof-wall building elements according to one embodiment of the present invention in a mounted and pivoted state;

Fig. 7 illustrates a plurality of roof-wall building elements according to one embodiment of the present invention stacked together for transport;

Fig. 8 shows a cross-sectional view of roof-wall building elements according to one embodiment of the present invention;

Fig. 9 shows a close-up of a cut-away portion of a roof-wall building element together with alignment means according to one embodiment of the present invention;

Fig. 10 shows a close-up view of cut-away portions of two roof-wall building elements connected side by side by means of fastening means according to one embodiment of the present invention;

Fig. 1 1 shows a perspective view of roof-wall building elements according to the present invention mounted along their ridge portions;

Fig. 12 shows a perspective view of roof-wall building elements according to the present invention mounted along their ridge portions and attached side by side;

Fig. 13 shows a close-up view of the side edges of two roof-wall building elements according to the present invention; Fig. 14 shows a close-up view of the side edge of a roof-wall building element according to the present invention, including alignment means;

Fig. 15 shows a close-up view of the side edge including a first bore of a roof- wall building element according to the present invention;

Fig. 16 shows a close-up view of fastening means securing two roof-wall building elements according to the present invention attached side by side;

Fig. 17 shows a close-up view of fastening means for attaching two roof-wall building elements according to the present invention side by side;

Fig. 18 shows a close-up view of alignment means for aligning two roof-wall building elements according to the present invention side by side;

Fig. 19 shows a cross-sectional view of a first bore in the side edge of a roof- wall building element according to the present invention.

Detailed Description of the Invention

The roof-wall building element and building structure will be described below more in detail, reference being made to the figures. However, the invention should not be considered limited to the embodiment or embodiments shown in the figures and described below, but may be varied within the scope of the claims.

With reference to Fig. 2, there is shown a building structure erected using a plurality of roof-wall building elements according to the present invention. The building structure may be used as e.g. a hangar, a tent, a shelter, a hall or any other structure having a big free ceiling height to create a large clearance. As may be seen in Fig. 2, the building structure has been mounted with an end wall element to create a closed space. Openings have been cut out to make doors and windows. The building structure also comprises one or more floor sections, which may be produced from the same material as the other building elements. It is also foreseen to erect the building structure without the floor sections on any suitable flat surface.

In Fig. 3, different perspective views of the building structure are shown, wherein the roof-wall building elements are clearly visible.

Fig. 4 illustrates a pair of roof-wall building elements according to one embodiment the present invention in a mounted state. Each roof-wall building element comprises a wall portion 1 and a roof portion 2. The roof portion 2 is disposed at an angle to the wall portion 1 . The angle may be chosen in the range 90° to 135°, depending on the use of the building structure. For a hangar constructed with roof-wall building elements of the present invention, a suitable angle would be about 120°.

The roof-wall building element is integrally formed as one single unit, includ- ing both the wall portion 1 and the roof portion 2. Alternatively, the roof-wall building element may be formed of separate wall and roof portions 1 , 2 that are joined together using any appropriate method, e.g. welding, adhesion, with the aid of fastening means, or a combination thereof.

As shown in Fig. 5, the roof portion 2 comprises a plurality of tubular units 4 that are spaced along its ridge portion 3. The tubular units 4 may be fastened to the ridge portion 3 of the roof portion 2 by welding, adhesion or any other suitable method. In one alternative, the tubular units 4 are welded onto V-shaped plates 5, which in turn are fastened to the ridge portion 3 of the roof portion 2.

As can be seen in Fig. 5, the spaces 6 between the tubular units 4 are of substantially the same size as the tubular units 4, such that when two roof-wall building elements are brought together to form a building structure, the tubular units 4 of the first roof-wall building element fit into the spaces 6 between the tubular units 4 of the second roof-wall building element, and vice versa, to form a piano type hinge. The piano type hinge may be secured by inserting a dowel (not shown) through the tubular units 4.

One advantage of the roof-wall building element according to one embodiment of the present invention is that it may be connected with another roof-wall building element when positioned lying on the ground and subsequently raised. On the contrary, hitherto-known building sections must be held upright during mount- ing which is labour-intensive and requires scaffolding and/or ladders.

Fig. 6 shows the two mounted roof-wall building elements of Fig. 4 in a raised state, i.e. the roof-wall building elements have been pivoted about the piano type hinge to form a building structure. As can be seen, the edges 18 of the ridge portions 3 of the roof portions 2 have been chamfered or bevelled such that the edges 18 rest flush against each other when the connected roof-wall building elements are brought to the upright position.

Another advantage of the present invention is illustrated in Fig. 7. Here is shown a plurality of identical roof-wall building elements that are stacked together in a compact manner. The roof-wall building elements have a substantially plane surface. Since there are no flanges along the sides, the roof-wall building elements are compact and allow for easy transport when stacked together.

Fig. 8 illustrates a cross-sectional view of a roof-wall building element according to one embodiment of the present invention. As may be seen, the roof-wall building element comprises at least one through-going bore 7 in a plane parallel to the surface of the roof-wall building element. Preferably, the roof-wall building element comprises a plurality of through-going bores 7, such as e.g. four. The through-going bores 7 extend laterally through the roof-wall building element from one side edge 8 to the opposite side edge 9. Preferably, the through-going bores 7 are directed parallel to a bottom edge 10 of the wall portion 1 , perpendicular to the side edges 8, 9, such that when two roof-wall building elements are brought together side by side, the at least one through-going bore 7 of the first roof-wall building element is aligned coaxially with the at least one through-going bore 7 of the second roof-wall building element.

The through-going bores 7 are adapted to receive alignment means 1 1 which may extend through the through-going bores 7 of adjacent roof-wall building elements when brought together side by side. Fig. 9 shows a close-up of the alignment means 1 1 together with a cut-away portion of the roof-wall building element. Also shown is a cut away portion of an end wall element 16. Preferably, the align- ment means 1 1 comprise a rod or tubular member 12 with threads 13 at its end portions. The length of the rod 12 is substantially equal to the width of the roof-wall building element to ensure a tight connection. A tubular connection member 14 is also provided having mating threads adapted to engage with the threads 13 of the rod 12. Preferably, the threads 13 are external while the threads of the connection member 14 are placed internally, but the opposite is also foreseen.

Furthermore, the connection member 14 comprises an axially centrally located flange 15 which acts as a spacer element between adjacent roof-wall building elements and holds each roof-wall building element in place when connected with the rod 12 extending through the through-going bore 7. A separate connection member 17 is used for the connection between the end wall element 16 and the roof-wall building element. The connection member 17 has a flange 15 which is located at one end thereof, rather than axially centrally, such that no part protrudes from the building structure when mounted. When mounting a building structure using the roof-wall building elements according to one embodiment of the present invention, in a first step, the ridge portions 3 comprising corresponding tubular units 4 of two roof-wall building elements are brought together to form a piano type hinge as explained above. The piano hinge is secured by inserting a dowel through the tubular units 4. Secondly, the two roof-wall building elements are pivoted about the piano hinge to an upright position such that the wall portions 1 are vertical and facing each other. The piano hinge forms the ridge of the erected building structure.

Now rods 12 are inserted through the through-going bores 7 and fastened to a connection member 14 at each end by means of the corresponding threads until the flanges 15 rests against the side edges 8, 9. Fig. 10 shows a close-up view of cut-away parts of two roof-wall building elements connected side by side by means of the alignment means 1 1 . Also, end wall element 16 is connected to the roof-wall building element using the separate connection member 17.

This process is repeated with pairs of roof-wall building elements connected by a piano hinge and brought adjacent the previously erected pair of roof-wall building elements until a building structure of desired size is obtained. The rods 12 of the new pair of roof-wall building elements are fastened to the already mounted connection member 14 in the previously erected pair of roof-wall building ele- ments.

Figs. 1 1 and 12 illustrate the principle of mounting and attaching roof-wall building elements according to the present invention. In a first step, two roof-wall building elements are connected along their ridge portions 3 when lying down on their side edges 8. The ridge portions 3 may be provided with flanges for secure and weather tight attachment. Then, in a second step, the roof-wall building elements are raised to an upright position and brought together side by side for attachment. The process is then repeated with subsequent pairs of ridge-mounted roof-wall building elements until a building structure of desired length has been achieved. To further improve the sealing of the ridge portions 3 a seal 24 may be arranged on the ridge after mounting. To assist in placement, the bottom edges of the wall portions 1 may be positioned in rails 25 along the ground.

Figs. 13-15 show close-up views of the side edge 8 of roof-wall building elements according to the present invention. In the side edge 8 there is provided a first bores extending substantially parallel with the surface of the roof-wall building element. The first bore 7 is adapted to receive alignment means 19 for ensuring correct placement of the roof-wall building elements when bringing them together side by side. As mentioned above in connection with one embodiment of the present invention, the bore 7 is through-going to accommodate the rod 12 acting as both alignment means and fastening means.

Adjacent the side edge 8 there is also provided a second bore 18 extending substantially perpendicular to the surface of the roof-wall building element. The second bore 18 is adapted to receive fastening means 20 for rigidly attaching two roof-wall building elements side by side, as shown in Fig. 16. The second bores 18 are disposed such that two second bores 18 of two adjacent roof-wall building elements are disposed substantially horizontal side by side at the same height. Naturally, the roof-wall building element may be provided with a plurality of first bores 7 and second bores 18 evenly distributed along the side edges 8, 9 to ensure proper alignment and attachment.

In Fig. 17, one embodiment of a fastening means 20 is illustrated. The fastenings means comprise a turnbuckle 20 or bottlescrew including a sleeve 21 and screws 22 at each end, threaded in opposite directions. The screws 22 are in turn connected to cylindrical tightening members 23 which are adapted to be inserted into the second bores 18 of two adjacently positioned roof-wall building elements. The shape of the tightening members 23, as well as the second bores 18, may of course differ from what is shown in Fig. 17. Advantageously, the size or diameter of the second bores 18 and the tightening members 23 may be adapted such that a friction fit is achieved upon insertion to ensure that the tightening members 23 remain in place. As an alternative, the surface of the tightening members may be pre-treated or covered with a material to increase the coefficient of friction thereof. Furthermore, the surface of the sleeve 21 of the turnbuckle 20 may be adapted to provide a better grip through added friction or given a shape to facilitate cooperation with a tool for tensioning. In one example shown in Fig. 17, the sleeve 21 has a hexagonal shape in cross-section to enable gripping and turning with a spanner or wrench.

In a different example of fastening means within the scope of the invention, similar in function to a cross dowel, the first and second bores 7, 8 are arranged in communication with each other such that a connection member may be inserted into the first bore 7 and a housing member may be inserted into the second bore perpendicularly to the connecting member. The housing member has a through- going hole for accommodating the connecting member. Furthermore, there is provided a gripping member which may be screwed into the housing member from the opening of the second bore 8 for frictional engagement with the connecting member. Thus, the gripping member holds the connecting member securely in relation to the housing member in the second bore 8 on each roof-wall building element.

Fig. 18 shows an embodiment of an alignment means 19. Here, the alignment means is a dowel 19 adapted to be inserted into the first bore 7 of a roof-wall building element. The shape of the dowel 19 is adapted to the varying diameter of the first bore 7, as illustrated in Fig. 19 to provide a proper fit. A first portion 19a of the dowel 19 has a constant diameter whilst a second portion 19b has an increasing diameter, giving it a conical shape. The dowel 19 is symmetrical about the centre with a third portion 19c displaying a decreasing diameter in a direction towards the opposite end until the diameter reaches the constant diameter of the first portion 19a. Then, in a fourth portion 19d, the diameter is constant and substantially equal to the diameter of the first portion 19a.

Similarly, the diameter of the first bore 7 varies along the longitudinal extension thereof. A first portion 7a of the first bore has a constant diameter, substan- tially corresponding to the diameter of the first portion 19a of the dowel 19. A second portion 7b of the first bore 7 has an increasing diameter in a direction towards the side edge 8, substantially corresponding to the increasing diameter of the second portion 19b of the dowel 19. The increasing diameter of the first bore 7 aids in aligning the dowel 19 with the first bore 7 when bringing two roof-wall building el- ements together side by side.

Advantageously, the roof-wall building elements of the present invention are made from a composite material which provides for lightweight but strong building elements that easily withstands rain, large snow loads and strong wind. One proposed composition for the roof-wall building elements is a sandwich construction with two external layers or skins made from fibreglass reinforced vinyl ester plastic and a spacer material such as Divinycell® therebetween. This gives the roof-wall building elements excellent insulating properties. Additionally, the roof-wall building elements may be casted with para-aramid fibres such as Kevlar® or Twaron® to provide shrapnel and bullet protection in cases where a building structure is intended for military use or in war zones.

Another possibility is to mould solar panels, cables and lighting into the roof- wall building elements and thereby make the building structure self-sufficient in electrical energy. Such moulding techniques are known in the art and will not be further described here.

Claims

1 . A roof-wall building element comprising a wall portion (1 ) and a roof portion (2) angularly disposed with respect to the wall portion (1 ) and comprising a ridge portion (3), wherein the roof portion (2) comprises means for connecting two roof- wall building elements along their ridge portions (3),

characterised in that the roof-wall building element comprises at least a first bore (7) in a side edge (8) of the roof-wall building and substantially parallel with the surface of the roof-wall building element and at least a second bore (18) adjacent the side edge (8) and substantially perpendicular to the surface of the roof-wall building element,

wherein the first bore (7) is adapted to receive alignment means (19; 1 1 ) and the second bore (18) is adapted to receive fastening means (20) such that when two roof-wall building elements are brought together side by side, the first bore (7) of the first roof-wall building element is aligned coaxially with the first bore (7) of the second roof-wall building element and the second bores (18) of the first and second roof-wall building elements, respectively, are disposed substantially side by side,

wherein the alignment means (19; 1 1 ) may extend into the first bores (7) and the fastening means (20) may extend into the second bores (18) in order to rigidly connect the two roof-wall building elements.

2. A roof-wall building element according to claim 1 , wherein the fastening means comprises a turnbuckle (20) including two screws (22) and a pair of tighten- ing members (23) connected to the screws (22) and adapted to be inserted into the second bores (18) of the roof-wall building elements.

3. A roof-wall building element according to claim 1 or 2, wherein the diameter of the first bore (7) varies along the longitudinal extension thereof, and the align- ment means comprises a dowel (19) having a shape corresponding to the shape of the first bore (7).

4. A roof-wall building element according to claim 3, wherein the diameter of the first bore (7) increases along at least a part (7b) of the longitudinal extension thereof in a direction towards the side edge (8).

5. A roof-wall building element according to any preceding claim, wherein the first bore (7) is through-going and extending laterally from the side edge (8) of the roof-wall building element to the opposite side edge (9) thereof.

6. A roof-wall building element according to claim 5, wherein the alignment means (1 1 ) comprises a rod (12) with substantially the same length as the width of the roof-wall building element and comprising threads at its end portions, and a tubular connection member (13) comprising corresponding threads.

7. A roof-wall building element according to claim 6, wherein the connection member (13) comprises a substantially centrally positioned flange (14).

8. A roof-wall building element according to any preceding claim, wherein the roof portion (2) comprises means (4) for pivotably connecting two roof-wall building elements along their ridge portions (3).

9. A roof-wall building element according to claim 8, wherein the pivotable connection means (4) comprise a plurality of tubular units (4) spaced along the ridge portion (3) such that when two roof-wall building elements are brought together to form a self-supporting building structure, the tubular units (4) of the first roof-wall building element fit into the spaces (6) between the tubular units (4) of the second roof-wall building element, and vice versa, to form a piano type hinge which may be secured by inserting a rod through the tubular units (4).

10. A roof-wall building element according to any preceding claim, wherein the two portions (1 , 2) are integrally formed as a single unit.

1 1 . A roof-wall building element according to any preceding claim, made from at least one composite material.

12. A roof-wall building element according to claim 1 1 , comprising a sandwich construction wherein two layers of composite material are interspaced with a spacer material.

13. A roof-wall building element according to any preceding claim, further comprising para-aramid fibres.

14. A roof-wall building element according to any preceding claim, further comprising solar panels, cables and lighting moulded into the construction.

15. A roof-wall building element according to any preceding claim, wherein the surface of the roof-wall building element is substantially plane such that the roof- wall building element is stackable together with a plurality of substantially identical roof-wall building elements.

16. A self-supporting building structure comprising a plurality of roof-wall building elements according to any preceding claim mounted together.