Structural unit for a building wall structure and a building wall structure

Abstract

The invention is a structural unit for a building wall structure, the structural unit comprising orthogonal bar elements (10) that are made of wood and are arranged in horizontal and vertical directions and diagonal bar elements (20) that are made of wood and are arranged obliquely with respect to the orthogonal bar elements (10). The orthogonal bar elements (10) are joined together pair-by-pair with respective cross half-lap joints, and the diagonal bar elements (20) are arranged in a 45° diagonal arrangement, with the 45° bevel cuts at their end portions fitting against each other, and are dimensioned and arranged in relation to the orthogonal bar elements (10) such that their end portions are between the laps formed at the ends of the orthogonal bar elements (10), wherein said laps and end portions between them are attached to each other with through fasteners (30) arranged in through bores.

Description

[0001] STRUCTURAL UNIT FOR A BUILDING WALL STRUCTURE AND A BUILDING WALL STRUCTURE

[0002] TECHNICAL FIELD

[0003] The invention relates to a structural unit for a building wall structure, the structural unit comprising orthogonal bar elements that are made of wood and are arranged in horizontal and vertical directions and diagonal bar elements that are made of wood and are arranged obliquely with respect to the orthogonal bar elements. The invention further relates to a building wall structure implemented with the structural unit.

[0004] BACKGROUND ART

[0005] Wooden building structures have been used for millennia, and their application has many advantages even nowadays. Wood is a renewable resource and has lower associated carbon dioxide emissions than other construction materials, for example concrete or steel. For the lifetime of the building, it is able to store carbon, which helps mitigate climate change. Wood is much lighter and cheaper compared to materials such as steel or concrete, so construction with wood is cheaper, especially from the aspect of the costs of foundations and shipping. Furthermore, wood is a natural insulation material that helps maintain indoor temperatures and reduces the energy costs related to heating and cooling. Wood is also beneficial from a sound insulation aspect, because it absorbs and / or dampens sound, so it is a good choice for residential buildings or areas requiring noise reduction. Wooden structures can often be built more quickly compared to concrete or steel structures, especially with prefabricated elements, which may reduce labour costs and time spent on-site. Wood is also versatile, and thanks to modern woodworking techniques it can be utilised for various types of buildings from small detached houses to large commercial buildings. By applying appropriate treatment and modern protection techniques, lumber can be very durable and is able to resist rot and pests.

[0006] However, wooden building structures also have some significant disadvantages, especially because according to the state of the art they are composed of relatively long elements (beams), collectively referred to as “bars.” Although wooden structures can be designed to span great distances, their inherent strength and rigidity is lower than that of steel or concrete. This may sometimes limit feasible spans or may require larger beams / bars, increasing materials costs. Wood is prone to rotting, warping and degradation when exposed to moisture. This is especially true for long beams and bars. It is also disadvantageous from the aspect of buckling and deformation if the timber is prone to such deformations / shape changes. In the case of long beams and bars this may necessitate additional costly reinforcements to ensure that the structure retains its shape over time. Depending on temperature and moisture fluctuations, longer wooden segments may undergo expansion and contraction to a significant degree, which may cause cracks, gaps or other problems if the structure has not been appropriately designed and / or has not been subjected to appropriate treatment.

[0007] A particularly significant disadvantage is that in the case of longer spans excellentquality timber must be applied, which may incur significant costs. High-quality timber required for long beams may not be readily available in all regions in the required amounts, which may lead to delays or may cause sourcing challenges. Furthermore, when high-quality timber is applied for building structures it may happen that the timber is sourced from unsustainable sources; deforestation or unsustainable logging practices may have negative environmental effects.

[0008] According to the state of the art, long one-piece bars can be replaced with bars made from multiple parts applying so-called “lap joints”, i.e., straight lap or half-lap joints, while applying so-called “cross lap joint” crossings can also be produced. In woodworking, the term “straight half-lap” refers to a splice joint that is mainly applied in carpentry. Such joints are typically made using tools like stair saw or dado saw, ridge plane and slitting plane. Laps or half-laps are woodworking joints wherein the pressure forces arising in the interconnected beams, bars or other elements are absorbed by the abutting portions, while tensile forces are absorbed by the usually applied adhesive bonds. In half-lap splice joints the elements to be spliced are lapped at half of their thickness; the length of the lap is approximately one and a half times the thickness. Applying a shorter lap results in a weaker joint, while a longer lap increases material waste. In cross lap or cross half-lap joints slits or notches are made to half of the thickness of the material.

[0009] US 7,658,049 B2 discloses load-bearing segments for application in building and wall structures. The load-bearing segments comprise a truss configuration, i.e., an assembly of members forming a rigid framework. This known approach has the disadvantage that it also applies long bars that have the disadvantages described above, and it does not provide a structure in which the bores for receiving the through fasteners do not significantly degrade strength.

[0010] DISCLOSURE OF THE INVENTION

[0011] The object of the invention is to provide a universal structural unit for a building wall structure and a building wall structure that eliminate to the greatest possible extent, or even completely remove, the drawbacks and shortcomings of prior art solutions. Another object of the invention is to provide a structural unit and a building wall structure that have no through fasteners at the locations where the vertical and horizontal bars meet each other, i.e., the structure is not weakened by the through bores of the fasteners at the locations that are the most critical from the aspect of the strength of the building structure. A further objective of the invention is to provide a universal structural solution that can be manufactured simply and cheaply, utilising timber from deciduous species that have been underused in the prior art.

[0012] The objects according to the invention have been achieved by the structural unit applicable for a building wall structure according to claim 1 and by the building wall structure according to claim 16. Preferred embodiments of the invention are defined in the dependent claims.

[0013] According to the recognition of the invention, in contrast to conventional solutions, the fasteners should not be disposed and the corresponding through bores should not be made at the locations where the vertical and horizontal bars meet each other, because bores made at such locations greatly reduce the strength of the structure. As it is typical for higher loads to occur at such joints, making these joints without bores is advantageous. However, because it is necessary to apply fasteners for interconnecting the bars, they must be disposed at other portions of the structure. According to the invention, the locations envisaged for that are the locations where the ends of the stiffening diagonal bar elements meet each other; this unconventional solution has improved strength by a previously unexpected extent, resulting in a so-called “short-bar” structure having particularly preferable characteristics.

[0014] The short-bar modular wall structure according to the invention has a number of additional key advantages. Using short bars allows for effective load distribution and ensures structural stability. Depending on various circumstances, buildings with short-bar wooden frames may prove preferable in regions with seismic risk or areas with dynamic soil properties. Short bars allow for a modular, flexible configuration. By providing a basic structural unit an easily expandable, versatile construction solution is obtained, the modular approach also making the construction process quicker and more cost-effective. It is possible to prefabricate the short bars in a controlled environment, and assemble them at the construction site. Assembling the structure from a plurality of identical elements simplifies the construction process, reduces labour costs, and minimises on-site disruptions. In addition, the invention makes it possible to use for construction purposes timber from deciduous species that have been underused in the prior art, such as hybrid poplar.

[0015] BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Preferred embodiments of the invention will be explained referring to the accompanying drawings, where

[0017] Fig. 1 shows a spatial view of a portion of an exemplary preferred building wall structure that is implemented applying a structural unit or structural units according to the invention,

[0018] Fig. 2A shows a spatial view of an orthogonal bar element applied in the structural unit shown in Fig. 1 , Fig. 2B shows a front view of the orthogonal bar element of Fig. 2A,

[0019] Fig. 2C shows a top plan view of the orthogonal bar element of Fig. 2A,

[0020] Fig. 2D shows a side view of the orthogonal bar element of Fig. 2A,

[0021] Fig. 3A shows a spatial view of a diagonal bar element applied in the structural unit shown in Fig. 1 ,

[0022] Fig. 3B shows a front view of the diagonal bar element of Fig. 3A,

[0023] Fig. 3C shows a top plan view of the diagonal bar element of Fig. 3A,

[0024] Fig. 3D shows a side view of the diagonal bar element of Fig. 3A,

[0025] Fig. 4A shows a spatial view of a fastener applied in the structural unit shown in Fig.

[0026] 1 ,

[0027] Fig. 4B shows a front view of the fastener according to Fig. 4A,

[0028] Fig. 4C shows a top plan view of the fastener according to Fig. 4A,

[0029] Fig. 5 is an exploded view of the portion of a building wall structure shown in Fig. 1 , depicting each structure layer,

[0030] Fig. 6A is a front view of the portion of a building wall structure shown in Fig. 1 ,

[0031] Fig. 6B shows a side view of the portion of a building wall structure of Fig. 6A, Fig. 6C shows a side view of the portion of a building wall structure of Fig. 6A, Fig. 7 is a spatial view of an exemplary building also comprising the portion of the building wall structure according to the invention shown in Fig. 1 .

[0032] MODES FOR CARRYING OUT THE INVENTION

[0033] Fig. 1 shows a spatial view of a portion of an exemplary preferred building wall structure, i.e. , a wall body section, that is implemented applying a structural unit or structural units according to the invention. A storey-high wall body can be formed by multiplying a single section to obtain an arbitrary length and height.

[0034] In respect of the portion shown in the figure, preferably one-fourth of the structure depicted in the drawing can be considered as a structural unit, i.e., an aggregate of the bar elements belonging to a cross shape and a square shape diagonally connected to it, including the corresponding fasteners. In such a structural unit, four orthogonal bar elements 10 and four diagonal bar elements 20 attached thereto are disposed. This structural unit can be expanded as desired applying further structural units, i.e., it can be multiplied arbitrarily in both directions of the wall plane, so it allows for modularly designed and implemented construction. Optionally, the entire building wall structure portion shown in Fig. 1 can be considered as a structural unit that is obtained by doubling the smallest unit in the horizontal and vertical directions, but of course other structural units created by multiplying the smallest unit can also be considered such structural units that may constitute basic units for a design or a construction.

[0035] As can be seen in Fig. 1 , the structural unit comprises orthogonal bar elements 10 that are made of wood and are arranged in horizontal and vertical directions and diagonal bar elements 20 that are made of wood and are arranged obliquely with respect to the orthogonal bar elements 10.

[0036] According to the invention, in the structure depicted in an exploded view in Fig. 5, and shown in a front view, side view, and top plan view, respectively, in Figs. 6A, 6B, 6C, the structural unit comprises a first structure layer 41 formed with orthogonal bar elements 10, a second structure layer 42 that is formed with orthogonal bar elements 10 arranged oppositely to the orthogonal bar elements 10 of the first structure layer 41 and is parallel to the first structure layer 41 , and a middle structure layer 43 that is between and abutting the first structure layer 41 and the second structure layer 42 and is formed with the diagonal bar elements 20.

[0037] In the structural unit according to the invention, each orthogonal bar element 10, depicted in Figs. 2A, 2B, 2C, and 2D in a spatial view, a front view, a top plan view, and a side view, respectively, comprises a notch 11 formed in a middle of the length of the orthogonal bar element 10 for a cross half-lap joint to join it to another orthogonal bar element 10, and a respective lap 12 formed at each end of the orthogonal bar element 10 for respective half-lap joints.

[0038] In the structural unit according to the invention, furthermore, each diagonal bar element 20 depicted in Figs. 3A, 3B, 3C, and 3D in a spatial view, a front view, a top plan view, and a side view, respectively, is configured at both of its end portions 22 with 45° bevel cuts 21 made along planes perpendicular to the structure layers 41 , 42, 43 (i.e., to their midplanes). According to the invention, an end portion 22 is meant to be a portion with bevel cuts 21 , or a portion including it.

[0039] In the first and second structure layers 41 , 42 of the structural unit, the orthogonal bar elements 10 are joined together pair-by-pair with respective cross half-lap joints, and the diagonal bar elements 20 are arranged in a 45° diagonal arrangement, with the 45° bevel cuts 21 fitting against each other, and are dimensioned and arranged in relation to the orthogonal bar elements 10 such that their end portions 22 are between the laps 12 formed at the ends of the orthogonal bar elements 10. Therefore, the longitudinal dimensions of the diagonal bar elements 20 are determined by the dimensions of the orthogonal bar elements 10, more specifically the locations of the laps 12: the laps 12 are able to enclose the end portions 22 of the diagonal bar elements 20 if the locations defined by the laps are connected by the lengths of the diagonal bar elements 20 along 45-degree diagonals. Therefore, knowing the dimensions, in particular the dimensions related to the laps, of the orthogonal bar elements 10 the length of the diagonal bar elements 20 can be calculated easily.

[0040] The laps 12 and the end portions 22 between them are attached to each other with through fasteners 30, preferably dowels, arranged in through bores 13, 23 formed in the end portions 22 and in the laps 12, the dowels being shown in spatial view, in front view, and in top plan view in Figs. 4A, 4B, and 4C, respectively. Of course, fasteners 30 with cross non-circular, for example rectangular sectional shapes can also be applied as fasteners 30, in which case the bores 13, 23 must have a configuration matching their shape. Other wood or metal fasteners, such as tapered dowels, screws, bolts, pegs etc. can also be applied as fasteners 30.

[0041] According to the recognition of the invention, therefore - in contrast to conventional solutions - the fasteners 30 are disposed in bores not at the locations where the vertical and horizontal bars meet, but instead the forces are transferred from the cross-lap joints (as nodes) to the half-lap joints by placing the fasteners 30 there. Accordingly, the typically multidirectional and higher loads occurring at the intersections of the vertical and horizontal bars can be dealt with by crossings formed without bores and therefore having higher load-bearing capacity and strength. The forces occurring at half-lap joints, i.e. simple splicing joints, are less problematic from the aspects of the magnitude and the direction of the forces, so the bores 13 are not a problem in their case. When aligned with the bores 23 of the diagonal bar elements 20, the same bores 13 provide a practical way of attachment. In the structure, triangular shapes are formed by the diagonal bar elements 20 that provide high strength for the entire structure; this unusual solution has improved strength by a previously unexpected extent, resulting in a so-called “short-bar” structure having particularly preferable characteristics.

[0042] The short-bar structural system according to the invention therefore consists of three bar structures (basic bar elements) that are arranged in mutually parallel planes and are coupled together with fasteners 30, preferably dowels. The orthogonally arranged elements of the two outer bar structures enclose the oblique (diagonal) middle elements that are arranged at 45 degrees. The three layers work together, and they provide stiffening to each other.

[0043] Preferably, one respective bore 23 is formed in each end portion 22 of each diagonal bar element 20, and in each lap (12) of each of said orthogonal bar elements (10) four bores 13 are formed, symmetrically to a longitudinal and a transverse midplane of each orthogonal bar element 10, said longitudinal and transverse midplanes being perpendicular to the structure layers 41 , 42, 43 (in other words, the plane of the wall).

[0044] From the aspect of the ability to be constructed simply it is preferable if the diagonal bar elements 20 are of identical shape, and are configured to be symmetrical to their midplane parallel to the structure layers 41 , 42, 43 and to each of their longitudinal and transverse midplanes perpendicular thereto, and if the four bores 13 are formed in each lap 12 at corners of a square having sides parallel to the orthogonal bar elements 10. In this case, the laps 12 may expediently have square shapes.

[0045] Also from the aspect of simple construction / installation it is preferable if the laps 12 have congruent shapes, particularly if the laps 12 are straight laps 12 configured to form a splice joint with a further orthogonal bar element 10. From the aspects of mass production and yet more simple assembly, the embodiment is particularly preferable wherein the orthogonal bar elements 10 are of identical shape, and one of the laps 12 is formed in the material of the orthogonal bar element 10 in a direction identical to the direction of the notch 11 , the other of the laps being formed in a direction opposite thereto. Such orthogonal bar elements 10 can be applied for constructing structures of any size in a simple manner, by repeatedly adding appropriately positioned orthogonal bar elements 10. Of course, other lap types, such as bevel laps can also be applied.

[0046] From the aspect of providing a simpler design and implementation of the connections delimiting the wall structure, the structure is configured symmetrically to the plane of the wall, that is, the orthogonal bar elements 10 of the first structure layer 41 and the orthogonal bar elements 10 of the second structure layer 42 are arranged mirror-symmetrically to a midplane of the structural unit which is parallel to the structure layers 41 , 42, 43.

[0047] The design and implementation can be simplified also in case the orthogonal bar elements 10 and the diagonal bar elements 20 have identical thickness in a direction perpendicular to the structure layers 41 , 42, 43, and / or if the orthogonal bar elements 10 and the diagonal bar elements 20 are configured to have a rectangular cross-sectional envelope (i.e. greatest) shape.

[0048] In a short-bar configuration that is particularly preferable according to the invention, the lengths of the sides of the rectangular cross-sectional envelope shape are equal to or greater than one-twentieth of the envelope (i.e. the greatest) length of the given bar element. Expediently, the 10 orthogonal bar elements have a length falling into the range of 0.5 m - 1.5 m, with the diagonal bar elements 20 being configured to have a length corresponding thereto.

[0049] In a preferred example, a notch 11 formed at the middle of the orthogonal bar elements 10 having an envelope length of 570 mm and a cross section of 50x70 mm (thickness x width) has a width of 70 mm and a depth of 25 mm, the laps 12 having a lap-area of 70x70 mm and thickness of 25 mm. The diagonal bar elements 20 can be configured to have a cross section of 50x50 mm or 50x49.5 mm (thickness x width). These dimensions are particularly preferable because laps with a size of 70x70 mm are able to completely enclose (with respect to the diagonal bar elements 20) such end portions 22 wherein the 45 ° bevel cuts 21 have a length of 35 mm, the tips of the end portions 22 meeting each other at the centre of the laps having a size of 70x70 mm. In such cases the obtained width of the diagonal bar elements 20 is 35 x A / 2 = 49.5 mm (which can be rounded to 50 mm). In this example, the fasteners 30 are expediently dowels with a diameter of 14 mm and a length of 150 mm. With these dimensions, the total envelope length of the diagonal bar elements 20 is = 353.6 mm (which can be rounded up to 354 mm).

[0050] From the aspect of using timber from underused deciduous species it is expedient if the orthogonal bar elements 10 and the diagonal bar elements 20 are made of wood having a density of 400 - 500 kg / m3(for example pine / spruce or hybrid poplar), and the fasteners 30 are dowels made of wood having a density of 550 - 850 kg / m3(for example Turkey oak or red oak). Expediently, these density values are to be considered for dry timber.

[0051] Preferably, to improve strength and stability, adhesive bonding can also be applied in the structural unit according to the invention, for example at the cross half-lap joints, at the fasteners 30 in the through bores 13, 23, or at other contact surfaces or nodes of the structure. Close-fit joints can also be preferably applied at the same locations, by themselves or additionally; or the entire structure may be provided with other joints or attachments.

[0052] The smallest structural unit that can be multiplied in the required number in both the horizontal and vertical directions is one-fourth of the structure shown in Fig. 1 . In such a basic structural unit, four orthogonal bar elements 10 and four diagonal bar elements 20 attached thereto are disposed.

[0053] In Fig. 7 there can be seen a spatial view of an exemplary (small) building also comprising the portion of the building wall structure portion according to the invention shown in Fig. 1. The building wall structure 50 comprises structural units that are interconnected in a manner shown in the figure; its structure is substantially created by reproducing these units.

[0054] The orthogonal system of the building wall structure 50 depicted in Fig. 7 consists of bars having identical configuration, with the exception of the bars located at comers, edges, and terminations that are expediently made with overhangs; the lap joints formed at the overhangs may be different from the laps 12 depending on the required structural configuration. The diagonally placed bars are identical. The orthogonally arranged bars are fit together with straight and cross half-lap joints. Both ends of the diagonally configured bars are machined to have 45-degree bevel cuts. The above-described peculiarity of assembling the bars lies in that there are no dowels in the cross-lap nodes, while in the nodes formed with straight half-lap joints the elements are joined by four dowels (in each node).

[0055] The building wall structure 50 may preferably also comprise, at one or both of its sides, panelled insulation containing wood chips. Instead of or in addition to the panelled insulation, injected insulation introduced into gaps between the orthogonal bar elements 10 and the diagonal bar elements 20 may also be applied, the injected insulation may preferably also comprise wood chips or other wood scrap materials.

[0056] The technical solution according to the invention can be applied for replacing CLT (Cross-Laminated Timber) support structure elements that require a much higher amount of timber to make; the solution according to the invention provides a strength equalling the strength of CLT boards while using much less timber. In a particularly preferable manner, the invention makes it possible to use timber from currently underused deciduous species, such as hybrid poplar, for construction purposes. Hybrid poplar is prone to warping and its timber has lots of knots and defects, but it can still be adequately applied in the short-bar structure according to the invention.

[0057] Factory assembly or on-site assembly of the structural units and building wall structures according to the invention can even be performed applying industrial robots, in particular in the case of the preferred embodiment wherein orthogonal bar elements and diagonal bar elements of identical shapes are applied. In the case of this embodiment, industrial robots can be programmed to carry out repetitive tasks that consist of simple step sequences and are performed with identical structural elements.

[0058] The present description includes examples for explaining the object of the invention, and to allow the skilled person to understand and implement the invention, including making any of the structural units or the entire structure. The invention of course covers further examples, embodiments and variants that fall into the scope defined by the claims but not mentioned in the present description.

Claims

CLAIMS1. A structural unit for a building wall structure, the structural unit comprising orthogonal bar elements (10) that are made of wood and are arranged in horizontal and vertical directions, and diagonal bar elements (20) that are made of wood and are arranged obliquely with respect to the orthogonal bar elements (10), characterised by comprising a first structure layer (41 ) formed with the orthogonal bar elements (10), a second structure layer (42) that is formed with orthogonal bar elements (10) arranged oppositely to the orthogonal bar elements (10) of the first structure layer (41 ) and is parallel to the first structure layer (41 ), and a middle structure layer (43) that is between and abutting the first structure layer (41 ) and the second structure layer (42) and is formed with the diagonal bar elements (20), each orthogonal bar element (10) in said structural unit comprising a notch (11 ) formed in a middle of the length of the orthogonal bar element (10) for a cross halflap joint to join it to another orthogonal bar element (10), and a respective lap (12) formed at each end of the orthogonal bar element (10) for respective half-lap joints, and each diagonal bar element (20) in said structural unit being configured at both of its end portions (22) with 45° bevel cuts (21 ) made along planes perpendicular to the structure layers (41 , 42, 43), the orthogonal bar elements (10) in the first and second structure layers (41 , 42) of the structural unit being joined together pair-by-pair with respective cross half-lap joints, and the diagonal bar elements (20), arranged in a 45° diagonal arrangement with their 45° bevel cuts (21 ) fitting against each other, being dimensioned and arranged in relation to the orthogonal bar elements (10) such that their end portions(22) are between the laps (12) formed at the ends of the orthogonal bar elements (10), wherein said laps (12) and end portions (22) between them are attached to each other with through fasteners (30) arranged in through bores (13, 23).

2. The structural unit according to claim 1 , characterised in that one respective bore(23) is formed in each end portion (22) of each diagonal bar element (20), and in each lap (12) of each of said orthogonal bar elements (10) four bores (13) are formed, symmetrically to a longitudinal and a transverse midplane of eachorthogonal bar element (10), said longitudinal and transverse midplanes being perpendicular to the structure layers (41 , 42, 43).

3. The structural unit according to claim 2, characterised in that the diagonal bar elements (20) are of identical shape, and are configured to be symmetrical to their midplane parallel to the structure layers (41 , 42, 43) and to each of their longitudinal and transverse midplanes perpendicular thereto, and the four bores (13) are formed in each lap (12) at corners of a square having sides parallel to the orthogonal bar elements (10).

4. The structural unit according to any of claims 1 to 3, characterised in that the laps (12) have congruent shapes.

5. The structural unit according to claim 4, characterised in that the laps (12) are straight laps (12), each of which are configured to form a splice joint with a further orthogonal bar element (10).

6. The structural unit according to any of claims 1 to 5, characterised in that the orthogonal bar elements (10) are of identical shape, and one of the laps (12) is formed in the material of the orthogonal bar element (10) in a direction identical to the direction of the notch (11 ), the other of the laps being formed in a direction opposite thereto.

7. The structural unit according to any of claims 1 to 6, characterised in that the orthogonal bar elements (10) of the first structure layer (41 ) and the orthogonal bar elements (10) of the second structure layer (42) are arranged mirror-symmetrically to a midplane of the structural unit which is parallel to the structure layers (41 , 42, 43).

8. The structural unit according to any of claims 1 to 7, characterised in that the orthogonal bar elements (10) and the diagonal bar elements (20) have identical thickness in a direction perpendicular to the structure layers (41 , 42, 43).

9. The structural unit according to any of claims 1 to 8, characterised in that the orthogonal bar elements (10) and the diagonal bar elements (20) are configured to have a rectangular cross-sectional envelope shape.

10. The structural unit according to claim 9, characterised in that the lengths of the sides of the rectangular cross-sectional envelope shape are equal to or greater than one-twentieth of the envelope length of the given bar element (10, 20).11 . The structural unit according to any of claims 1 to 10, characterised in that the orthogonal bar elements (10) have a length falling into the range of 0.5 m - 1 .5 m.

12. The structural unit according to any of claims 1 to 11 , characterised in that the orthogonal bar elements (10) and the diagonal bar elements (20) are made of wood having a density of 400 - 500 kg / m3, and the fasteners (30) are dowels made of wood having a density of 550 - 850 kg / m3.

13. The structural unit according to claim 12, characterised in that the orthogonal bar elements (10) and the diagonal bar elements (20) are made of hybrid poplar, and the dowels are made of Turkey oak or red oak.

14. The structural unit according to any of claims 1 to 13, characterised in that the cross half-lap joints and the fasteners (30) in the through bores (13, 23) are closely fit and are also secured with adhesive.

15. The structural unit according to any of claims 1 to 14, characterised in that four orthogonal bar elements (10) and four diagonal bar elements (20) attached thereto are disposed in each structural unit.

16. A building wall structure (50) characterised by comprising structural units that are configured according to claim 15 and are connected to one another.

17. The building wall structure (50) according to claim 16, characterised by comprising, at one or both sides thereof, panelled insulation containing wood chips.

18. The building wall structure (50) according to claim 16 or 17, characterised by comprising injected insulation introduced into gaps between the orthogonal bar elements (10) and the diagonal bar elements (20).

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