Modular building system

Abstract

The invention relates to a modular building system comprising 2D frame members and block-like node members forming a precise building framework. The node members include full-size cubic nodes with threaded holes at the midpoint of each of their twelve edges, aligned along 2-fold symmetry axes for coupling to notched corners of 2D frame members. Truncated nodes, with one, two, three or four faces removed, have fewer threaded holes, enabling flush alignment of its truncated faces with attached 2D frame members. The 2D frame members, with a rectangular perimeter, feature notched corners with recesses having two bearing surfaces that abut two faces of a coupled node member. This ensures slack-free connections, aligning node faces parallel or perpendicular to frame edges and faces. The system, manufactured with high precision, offers dimensional accuracy, simplified assembly, and versatility for structural applications.

Description

[0001] MODULAR BUILDING SYSTEM

[0002] TECHNICAL FIELD

[0003] The subject disclosure relates to a modular building system and more particularly to a modular building system of which the components are reusable after disassembly of the building system. The subject disclosure further relates to components for use in such a modular building system.

[0004] BACKGROUND

[0005] At present, the construction industry is responsible for about 33% of the total waste disposal and 31% of total energy usage. From this waste, about 47% goes to landfill, 10% to backfill, 37% is recycled and what remains is burned. The construction industry produces furthermore 9% of the total greenhouse gas emissions. It is therefore of the utmost importance to find sustainable solutions to significantly reduce the negative impact of the construction industry on the environment.

[0006] A modular building structure is known for instance from W02017 / 122070A1 . This modular building structure is obtained by assembling a plurality of module frames to obtain a complex frame, and comprises walls and floors implemented by suitable cladding panels. The module frames have a substantially parallelepiped shape. This allows an easy assembly of modules equipped with finishing’s which leaves a free space which can be exploited in order to place technical plants and the like, and it comprises a plurality of connecting knots joining module frames adjacent on a same plane, on the lower side or upper side at angles, or which knots provides for the connection of module frames to a flat basement or roof structure. The module frames fit in commonly used containers with standard sizes, without requiring the use of special transportation devices.

[0007] WO99 / 67472 describes a modular construction system for a spatial structure, and comprises a number of node elements and structure elements to be held in position by and between these node elements, and coupling elements to be connected to a node element and a structure element for coupling a node element to a structure element to be held in position by this node element.

[0008] GB151899A describes a construction assembly, for cabinets and the like and of the kind comprising a framework covered with panels. The framework comprises elongated frame members whose ends are releasably connectable together by means of connecting elements and screws each having a head and a threaded shank which extends at an angle to the longitudinal axes of the members on assembly of the framework. The connected ends of the members being retained securely by the screws against a connecting element and being shaped in such a manner that each associated screw can be turned by a tool acting on the screw head and having a working axis which is coaxial with the axis of the screw shank extending at an angle to the longitudinal axis of a respective frame member.

[0009] DE4417896A1 describes rectangular frame elements for the construction of shops and / or exhibitions. Node parts are used to couple frame elements. When coupled, node parts rest with corresponding inclined surfaces against the bevelled corners of the frame element.

[0010] SUMMARY

[0011] It is an objective of the invention to provide a lightweight and high- resolution modular building system, versatile and designed for easy assembly, disassembly and adaptability of building structures. This is the way forward for achieving the highest possible degree of circularity in the building environment, provided the materials used are derived from sustainable sources and each and every part of this building system can be used many times without limitations or generation of waste. The modular building system comprises at least one of the following advantages: a limited number of lightweight building elements; elements that can be lifted manually; precise linking of elements; easy-to-manufacture elements with accurate dimensions; fully adaptable and 100% circular building system with high dimensional accuracy for the creation of 3D supporting structures; possibility of creating orthogonal building structures and more complex support structure such as domes and sloping roofs; the modular grid is accessible for the passage of installation technology including cable ducts and pipes, approximately 3 - 5 times lighter in weight in comparison with traditional construction with a concrete support structure; extensions such as balconies, conservatories, etc. can be realised without too much effort, even afterwards without waste and / or loss of material.

[0012] According to the invention, this object is achieved by a modular building system comprising frame members and block-like node members having the features of Claim 1. Advantageous embodiments and further ways of carrying out the invention may be attained by the measures mentioned in the dependent claims.

[0013] According to an aspect of the invention, Modular building system comprising frame members and block-like node members forming a building framework. The block-like node members include at least one of full-size cubic nodes and truncated nodes. Each full-size cubic node is provided with a threaded hole at the midpoint of its twelve edges, the threaded holes having a central axis coinciding with 2-fold symmetry axes passing through the midpoints of opposite edges of the cubic node. Furthermore, each edge is configured to couple to a notched corner of a 2D frame member; optionally each full-size cubic node is provided with through holes each having a central axis coinciding with 4-fold symmetry axes passing through the centre of opposite faces of the cubic node. Each truncated node comprises a portion of a full-size cubic node with one, two, three, or four truncated faces. The truncated nodes corresponds to a full-size cubic node of which one, two, three or four faces are truncated by removing a layer of material from said one or more faces resulting in the truncated faces, thereby reducing the number of twelve edges provided with a threaded hole. The 2D frame members have a rectangular shape and a thickness less than the length of an edge of a full-size cubic node. The 2D frame members comprise notched corners each having a recess configured to receive an edge of a block-like node member. Each notched corner is provided with a mounting structure with a through-hole for securing the 2D frame member to a block-like node element by a bolt engaging the threaded hole. The recess of the notched corner provides two bearing surfaces that abut the two faces adjacent to the edge of the blocklike node member that is coupled to the 2D frame member, aligning the node and frame member such that the node’s faces are parallel or perpendicular to the frame’s side edges and faces.

[0014] The core idea of the present technology is based on the recognition that, in constructing a relatively long supporting structure from multiple interconnected elements, the dimensional accuracy of the individual elements and the tolerances between their connections critically determine the final dimensional accuracy of the overall structure. Additionally, it is essential that the connected elements are fixed in a well-defined orientation relative to each other, and that the connection can be established in a simple and reliable manner.

[0015] The distinguishing features of the disclosed modular building system address these needs by providing a construction method wherein, by tightening a single bolt, an edge of a node is drawn into a notched corner of a 2D frame member and automatically aligned such that the adjacent faces of the node and frame become mutually perpendicular or parallel. This precise alignment is achieved through the interaction of well-defined bearing surfaces within the notched corner that engage the faces adjacent to the node edge. The modular building system achieves exceptional dimensional accuracy and rigidity through precise manufacturing and coupling of its components. Block-like node members, produced with high precision using CNC machining, feature threaded holes at edge midpoints for secure coupling. 2D frame members, accurately fabricated by laser cutting, stamping, or roll-forming sheet metal, include notched corners with recesses and mounting structures. When a node’s edge is coupled to a notched corner via a bolt engaging the threaded hole, the recess’s bearing surfaces abut the node’s adjacent faces, eliminating play in the longitudinal and transverse directions of the 2D frame member. Only the dimensional tolerances of the nodes and 2D frame members affect the framework’s accuracy, ensuring a rigid, repeatable connection. This design facilitates easy assembly, minimizes cumulative errors, and is particularly advantageous for modular and large-scale structural assemblies, offering reliability and versatility in diverse construction applications.

[0016] In an embodiment, the recess at each notched corner of the 2D frame member is mirror-symmetrical with respect to a diagonal plane bisecting the notched corner, and wherein the two bearing surfaces of the recess are mutually perpendicular.

[0017] An advantage of the recess being mirror-symmetrical with respect to a diagonal plane bisecting the corner, and having two mutually perpendicular bearing surfaces, is that each notched corner of a 2D frame member is geometrically compatible with any edge of a block-like node member that is provided with a threaded hole. This symmetry ensures that the frame member can be mounted in multiple orientations without requiring different or specially oriented recess geometries. As a result, the number of unique parts is minimized, assembly is simplified, and orientation errors during construction are effectively prevented, while still achieving precise alignment between the node and the frame member.

[0018] In an embodiment, each edge of the block-like node members provided with a threaded hole is chamfered at least around the threaded hole, wherein the chamfer forms a surface perpendicular to the central axis of the threaded hole.

[0019] An advantage of chamfering the edge of the block-like node member around the threaded hole, such that the chamfered surface is perpendicular to the central axis of the threaded hole, is that it facilitates accurate insertion and alignment of a threaded fastener into the hole. This reduces the likelihood of cross-threading or damaging the internal or external thread during assembly, thereby improving reliability, reducing assembly time, and prolonging the functional life of the threaded connection.

[0020] In a further embodiment, the chamfer extends along the entire edge. An advantage of the chamfer extending along the entire edge of the block-like node member is that it enables a 2D frame member connected at four corners to be easily removed from an existing framework structure by loosening the four bolts at its corners and moving the frame member in a direction aligned with the orientation of the edge. Similarly, a new 2D frame member can be conveniently replaced between four node members of an existing construction, as the continuous chamfer provides clearance and guidance during assembly and disassembly.

[0021] In an embodiment, each truncated node is configured such that the truncated face(s) lie flush with the faces of the 2D frame members attached thereto, aligning the truncated face(s) of the truncated node with the side surfaces of the 2D frame members in the building framework.

[0022] An advantage of configuring each truncated node such that its truncated face(s) lie flush with the faces of the 2D frame members attached thereto is that surface panels or sheathing can be applied directly over the nodes without requiring any modification or removal of material from the panels. This simplifies installation, reduces labour, and preserves the integrity and appearance of the sheathing. As a result, the sheathing can also be reused more frequently, since it remains undamaged during installation and removal.

[0023] In an embodiment, the block-like node members further include a two part composite full-size node comprising: a body part and an add-on part. The body part corresponding to a portion of a full-size cubic node with one truncated face, the body part having a recess in the truncated face and a threaded through hole in the centre of the truncated face an perpendicular to the truncated face. An add-on part corresponds to the missing portion of the body part to obtain a full-size cubic node. The add-on part comprises one face and four edges, each edge provided with a threaded hole corresponding to a threaded hole at an edge of a full-size cubic node. The add-on part further comprises an unthreaded counterbore through hole, and a protrusion configured to fit rotationally into the recess of the body part. The body part and the add-on part are coupled by a bolt in the counterbore through hole of the add-on part engaging the threaded through hole of the body part. Furthermore, the truncated face is flush with the faces of the 2D-frame members attached to the edges which are perpendicular to the truncated face.

[0024] An advantage of the composite full-size node composed of a body part and an add-on part is that it enables rotational flexibility between 2D frame members attached to the add-on part relative to those attached to the body part, while maintaining the mutual parallel or perpendicular alignment of the frame members along the rotational axis. This allows greater design freedom in constructing angular or faceted surfaces without compromising structural coherence. Additionally, the body part can often be used effectively at the exterior of a structure, as its truncated face provides a flat surface suitable for flush application of external cladding or panels. This not only simplifies installation of sheathing but also contributes to material efficiency, as truncating the node reduces material use where full structural volume is not required.

[0025] In an embodiment, the block-like node members further include three part composite full-size nodes, each comprising: a middle body part and two add-on parts. The middle body part corresponding to a portion of a full-size cubic node with two opposite faces truncated. The middle body part having a recess in each the truncated faces and an unthreaded through hole in the centre of the truncated faces. Each of the add-on parts corresponds to a missing portions of the body part to obtain a missing face of a full-size cubic node. Each add-on part comprises one face and four edges. Each edge provided with a threaded hole corresponding to a threaded hole at an edge of a full-size cubic node. The add-on part further comprising an unthreaded counterbore through hole, and a protrusion configured to fit rotationally into the recess of the body part. The body part and the two add-on parts are coupled by an Allen screw engaging the unthreaded through hole of the body part and the hexagonal nut in the counterbore through hole of one of the add-on parts.

[0026] An advantage of the three-part composite full-size node is that it allows for even greater configurational flexibility within the modular building system. By separating the node into a middle body part and two add-on parts, the system enables independent attachment of 2D frame members on opposite sides of the node, while preserving orthogonal or parallel alignment between those frame members. The rotational fit between each add-on part and the middle body part allows the attached 2D frames to be oriented independently, which is particularly useful for constructing complex geometries or dynamic modular connections.

[0027] Moreover, the middle body part, characterized by its two opposing truncated faces, is especially well suited for use in structural elements that are to be clad on both sides, such as interior partition walls. Its flat opposing faces provide ideal mounting surfaces for panels or sheeting, facilitating clean and efficient double-sided finishing. This not only simplifies construction but also increases the modularity and reusability of both nodes and cladding materials. Additionally, the omission of material at both ends of the middle body part results in a reduction in material usage compared to a full solid cubic node. This contributes to more efficient production, reduced weight, and lower material costs, particularly in large-scale applications where many such nodes are used.

[0028] In an embodiment, one or more 2D frame members further comprises one or more recesses along its edges, each recess configured to accommodate a face of a block-like node member and opposite edges of said face. Opposite ends of each recess has a similar shape as the notched corners. Furthermore, each recess is provided with three mounting structures with a through-hole for aligning a block-like node member to an edge of the 2D frame member by one, two or three bolts engaging a corresponding threaded hole of the block-like node member.

[0029] An advantage of the feature described in claim 8, wherein one or more 2D frame members include one or more recesses along their edges configured to accommodate a face of a block-like node member, is that it enhances the adaptability and efficiency of the modular building system. These intermediate recesses, shaped similarly to the notched corners, allow a block-like node member to be mounted not only at the corners but also along the edges of a 2D frame member. This makes it possible to initially minimize the number of block-like node members used in a structure, thereby reducing material use and production cost during early-stage construction.

[0030] By strategically placing larger 2D frame members with these recesses in a structure, designers retain the flexibility to later attach additional block-like node members at specific positions, without having to remove or replace existing frames. This is particularly beneficial in scenarios where post-construction adjustments are needed, such as repositioning partition walls or expanding modular sections of a building.

[0031] Moreover, the recesses in the side edges of the frame can serve as functional channels for routing flexible electrical conduits. This facilitates access to any point in the structural framework where electrical power is required, without needing major structural modifications. Thus, the feature promotes both mechanical modularity and infrastructure integration, supporting long-term adaptability and reduced construction downtime.

[0032] In an embodiment, one or more 2D frame members are composed of U- profiles and corner brackets, wherein the U-profiles form the 2D-frame member having a rectangular shape, with a perimeter formed by U-profiles and notched corners .At least one corner bracket is attached to corresponding inner sides of ends of adjacent U-profiles to connect the ends of two adjacent U-profiles, forming a notched corner with a recess configured to receive an edge of a block-like node member.

[0033] In this configuration, U-profiles form the rectangular shape of the 2D-frame frame, while the corner brackets connect the adjacent ends of two U-profiles at the inner corners, thereby forming a notched corner with a recess suitable for receiving an edge of a block-like node member.

[0034] This design offers practical benefits in terms of manufacturing and structural performance. U-profiles are relatively simple and cost-effective to produce with high dimensional accuracy using standard roll-forming or bending processes. Their geometry inherently provides sufficient rigidity for use in non-load-bearing applications, such as partition walls in modular construction.

[0035] In addition, the corner brackets not only connect the U-profiles but also incorporate the mounting structure required to attach a node to a corner of the frame. This dual functionality simplifies the construction process and reduces the number of unique components needed in the system, further supporting efficient, modular, and scalable building assembly.

[0036] In an embodiment, the bearing surfaces of the recess of a notched corner formed by the connection of two adjacent U-profiles are defined by the end faces of bottoms of the adjacent U-profiles.

[0037] An additional advantage is obtained with the feature that the bearing surfaces of the recess of a notched corner, formed by the connection of two adjacent U- profiles, are defined by the end faces of the bottoms (base walls) of the adjacent U- profiles. This means that, upon assembly, the precise length of the U-profiles directly determines the distance between two block-like node members connected at adjacent corners of a 2D frame.

[0038] This approach allows for a high degree of dimensional control and repeatability in the overall construction framework. Because the end faces of the U- profiles’ base walls are planar and can be cut with high accuracy, the effective spacing between node elements is no longer affected by tolerances in the bracket or fastener dimensions. This contributes to a consistent modular grid throughout the building framework and simplifies the design, manufacturing, and quality assurance processes.

[0039] In an embodiment, one or more 2D frame members are composed of two parallel, substantially rectangular plates, which are connected to each other with spacer elements, wherein corners of the rectangular plates are provided with the recess configured to receive an edge of a block-like node member having a threaded hole and provide the bearing surfaces.

[0040] This design results in highly rigid 2D frame members that are well suited to serve as supporting girders within a modular building framework. The dual-plate configuration, in combination with spacer elements, ensures high structural stiffness while maintaining modular compatibility with the node members. These frame members can span greater distances and bear higher loads than single-plate frames, making them particularly advantageous for use in primary load-bearing elements of a structure.

[0041] In an embodiment, the full-size cubic nodes have a length, width and height of C, the 2D-frame members have a thickness of F and the layer of material virtually removed from said one or more faces of the full-size cubic node, resulting in the truncated faces of a truncated node, has a thickness of (C - F) / 2.

[0042] This specific dimensional relationship ensures that the truncated face of a block-like node member aligns flush with the outer side surfaces of the 2D frame members to which it is attached.

[0043] This alignment facilitates the integration of the nodes into flat surfaces, enabling seamless application of cladding or panel materials without requiring additional shaping or notching.

[0044] In an embodiment, when two 2D frame members are coupled via their notched corners to opposite edges of a face of a block-like node member, the distance between facing parallel outer edges of the two 2D frame members corresponds to the thickness of a 2D frame member.

[0045] This feature allows a third 2D frame member to be inserted perpendicularly between the two existing frame members without requiring disassembly of the structure. This feature simplifies the modification or extension of an existing framework, for example when adding a new wall or partition. It supports a modular and flexible construction process in which elements can be added or repositioned efficiently, even in a late design stage or during renovations.

[0046] BRIEF DESCRIPTION OF THE DRAWINGS

[0047] These and other aspects, properties and advantages will be explained hereinafter based on the following description with reference to the drawings, wherein like reference numerals denote like or comparable parts, and in which:

[0048] Fig. 1 shows an illustrative embodiment of 2D-frame members coupled together by block-like node members, Fig. 2 illustrates embodiments of block-like node members,

[0049] Fig. 3 illustrates embodiments of 2D frame members composed of 2 parallel rectangular plates,

[0050] Fig. 4 illustrates embodiments of U-profiles,

[0051] Fig. 5 illustrates parts used to assemble 2D frame members and coupling components,

[0052] Fig. 6 illustrates a cross-sectional view of the coupling of three different embodiments of 2D frame members to a block-like node member,

[0053] Fig. 6A illustrates the dimensional relationship between truncated nodes and 2D frame members,

[0054] Fig. 7A - 7D illustrates a two part composite full-size node with first-type edges and corresponding notched corner of a 2D frame member, and coupling details,

[0055] Fig. 8A - 8D illustrates a two part composite full-size node with second-type edges and corresponding notched corner of a 2D frame member, and coupling details,

[0056] Fig. 9A - 9D illustrates a two part composite full-size node with third-type edges and corresponding notched corner of a 2D frame member, and coupling details,

[0057] Fig. 10A -10B respectively illustrates a perspective view and cross- sectional view of an additional coupling element to couple sides of 2D frame members composed of U-profiles,

[0058] Fig. 11A -11 B respectively illustrates a perspective view and cross- sectional view of an additional coupling element to couple sides of 2D frame members composed of two parallel rectangular plates,

[0059] Fig. 12 shows a first embodiment of coupling U-profiles to form a truncated corner of a 2D frame member,

[0060] Fig. 13 shows a second embodiment of coupling U-profiles to form a truncated corner of a 2D frame member and coupling the corner to a middle part of a three part composite full-size node,

[0061] Fig. 14 illustrates a diagonal connection of a 2D frame member,

[0062] Fig. 15 illustrates a detail of Fig.14,

[0063] Fig. 16 illustrates incorporation of infrastructure in the building structure,

[0064] Fig. 17 illustrates a detail of Fig. 16 showing a perspective view of coupling four 2D-frame members to a single node,

[0065] Fig. 18 shows a cross-sectional view of Fig. 17,

[0066] Fig. 19 illustrates a part of a frame work assembly, Fig. 20 illustrates the part of the frame work assembly shown in Fig. 19 partially covered with sheathing panels.

[0067] The drawings are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. Any reference signs in the claims shall not be construed as limiting the scope. In the different drawings, the same reference signs refer to the same or analogous elements.

[0068] DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0069] The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are nonlimiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. The dimensions and the relative dimensions do not correspond to actual reductions to practice of the invention.

[0070] Furthermore, the terms first, second and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

[0071] Moreover, the terms top, under, left, right, and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other orientations than described or illustrated herein.

[0072] It is to be noticed that the term “comprising”, used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression “a device comprising means A and B” should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B. Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

[0073] Similarly, it should be noted that in the description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

[0074] Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0075] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

[0076] The same or similar reference numerals may be used to indicate same or similar structural features in different embodiments.

[0077] The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are nonlimiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. The dimensions and the relative dimensions do not correspond to actual reductions to practice of the invention. The definitions of the symmetry axes of a cube can be described as follows:

[0078] 2-fold symmetry axis: A 2-fold symmetry axis of a cube is an axis passing through the cube such that a rotation of 180 degrees (or IT radians) about this axis maps the cube onto itself. For a cube, these axes pass through the midpoints of opposite edges. A cube has six 2-fold symmetry axes, each corresponding to a pair of opposite edges.

[0079] 3-fold symmetry axis: A 3-fold symmetry axis of a cube is an axis passing through the cube such that a rotation of 120 degrees (or 2TT / 3 radians) about this axis maps the cube onto itself. For a cube, these axes pass through pairs of opposite vertices of the cube, coinciding with the body diagonals. A cube has four 3-fold symmetry axes, each running from one vertex to its diagonally opposite vertex.

[0080] 4-fold symmetry axis: A 4-fold symmetry axis of a cube is an axis passing through the cube such that a rotation of 90 degrees (or TT / 2 radians) about this axis maps the cube onto itself. For a cube, these axes pass through the centres of opposite faces of the cube, perpendicular to those faces. A cube has three 4-fold symmetry axes, each corresponding to a pair of opposite faces (e.g., top and bottom, left and right, front and back).

[0081] Fig. 1 illustrates the basic concept of the present subject disclosure. It shows three 2D-frame members 300 and four block-like node members 200. Two of the 2D-frame members are connected at their corners via two block-like node members, forming an L-shaped configuration. The connection occurs at the corners of the 2D-frame members and at adjacent edges of the block-like node members. When a block-like node member is rigidly fastened to a corner of a 2D-frame member by a bolt (not shown), the alignment between the node and the frame member is ensured by the complementary geometry of the node’s edge and the recess at the corner of the frame member. As a result, the faces and edges of the 2D-frame member are either parallel or perpendicular to the faces of the block-like node member.

[0082] The third 2D-frame member is attached at its short edge to the face of one of the previously connected 2D-frame members, using two block-like node members. Together, they form a T-shaped structure. Each block-like node member is connected along one of its edges to a corner of the third 2D-frame member, and along an adjacent face to the edge of the other 2D-frame member. Due to the specific shapes of the recesses, at the corner of the third frame member and at the edge of the other, the blocklike node members align both frame members when secured using bolts. This ensures that the faces and edges of the 2D-frame members are parallel or perpendicular to the corresponding faces of the block-like node members.

[0083] Once all three 2D-frame members are joined by the block-like node members, two of the 2D-frame members are positioned parallel to each other, while the third is oriented perpendicularly to them.

[0084] A brief description of the main components used in the modular building system, as illustrated in Figures 2 to 5, will now be provided. This will be followed by a more detailed explanation of how block-like node members are coupled to 2D-frame members, as shown in Figures 5 to 9. Subsequently, various embodiments of subassemblies constructed using these components will be disclosed.

[0085] Fig. 2 illustrates embodiments of ten different nodes. Each embodiment is shown from an angled ISO-view from above and an angled view from below. Nodes are configured to be coupled to a corner of at least one 2D frame members.

[0086] Nodes are available in different variants. For instance full-size cubic nodes 200, and truncated nodes 210, 220, 230, 240, 250 and 260 for corners and in all places where panels have to be mounted flush to the structure. Composite nodes 270, 280 and 290 have features which enable them to be adjusted in size and orientation where these adjustments are needed. For example: when the distance between two structural frames varies, due to deflection under load and / or its own weight, the spacers 34 can vary in thickness or can be removed in order to provide the necessary allowance for assembling the structural elements in between.

[0087] A first embodiment of a node is a full size cubic node 210. The node is cubical, with a threaded hole 201 at the midpoint of each of its twelve edges. Each threaded hole has a central axis coinciding with a 2-fold symmetry axis of the node, intersecting and perpendicular to a virtual line corresponding to the edge and inclined at 45 degrees to the faces forming that edge. To facilitate bolt insertion, each edge with a threaded hole is chamfered, with the chamfer’s plain surface 205 oriented at a 45-degree angle to the adjacent faces and perpendicular to the threaded hole’s central axis. This chamfered design also simplifies the placement of a 2D frame member between four nodes in an existing framework, enhancing assembly efficiency.

[0088] Optionally, a full-size cubic node is provided with one or more threaded or unthreaded holes 202, 204, each with a central axis coinciding with 4-fold symmetry axes passing through the centre of opposite faces and perpendicular to those faces. As shown in figure 2, the top side of the full-size cubic node 200 features a counterbore hole 203 which is an unthreaded hole 204 designed to fully accommodate the head of a bolt. Each threaded hole 202 enables the node to be secured to a side of a 2D frame member using a bolt, which passes through a mounting structure on the 2D frame member and engages the threaded hole, ensuring a rigid connection with the node’s face aligned parallel or perpendicular to the frame’s side edges and faces. This configuration provides additional coupling flexibility, complementing the edge-based coupling via notched corners and enhancing the versatility of the modular building system.

[0089] The second embodiment of a block-like node member is a one-face truncated node 210. This node corresponds to a portion of the full-size-cubic node 200 wherein one face 211 is truncated, meaning the top portion of the full-size cubic node is absent. This truncation reduces the node’s height in the direction perpendicular to the truncated face, eliminating the four threaded holes at the edges of the truncated face, resulting in at most eight threaded holes at the remaining edges. When 2D frame members are coupled to the one-face truncated node via their notched corners, with bolts engaging the threaded holes, the truncated face aligns flush with the faces of the attached 2D frame members, ensuring a smooth, level surface.

[0090] A third embodiment of a node is a two-adjacent-faces truncated node 220. This node corresponds also to a portion of the full-size cubic node 200 wherein two faces are truncated. This truncation reduces the node’s height in the direction perpendicular to the top face and its width in the direction perpendicular to the side face, eliminating the four threaded holes at the edges of each truncated face, resulting in at most five edges, each provided with a threaded hole. When 2D frame members are coupled to the two- adjacent-faces truncated node via their notched corners, with bolts engaging the threaded holes, the truncated top and side faces align flush with the faces of the attached 2D frame members, ensuring a smooth, level surface.

[0091] The fourth embodiment of a block-like node member is a three-adjacent- faces truncated node 230. This node corresponds also to a portion of the full-size cubic node 200 wherein three faces are truncated. In Fig. 2 the top face and two adjacent side faces. This truncation reduces the node’s height in the direction perpendicular to the top face and its width in the direction perpendicular to the side faces, eliminating the four threaded holes at the edges of each truncated face, resulting in at most three edges, each provided with a threaded hole. When 2D frame members are coupled to the three- adjacent-faces truncated node via their notched corners, with bolts engaging the threaded holes, the truncated top and side faces align flush with the faces of the attached 2D frame members, ensuring a smooth, level surface. The fifth embodiment of a block-like node member is an opposite-face truncated node 240. This node corresponds also to a portion of the full-size cubic node 200 wherein two opposite faces are truncated. In Fig. 2 the top face and bottom face. This truncation reduces the node’s height in the direction perpendicular to the top face, eliminating the four threaded holes at the edges of each truncated face, resulting in at most four edges, each provided with a threaded hole. When 2D frame members are coupled to the opposite-face truncated node via their notched corners, with bolts engaging the threaded holes, the truncated top and bottom face align flush with the faces of the attached 2D frame members, ensuring a smooth, level surface. This node can be utilized in the plain sections of a partition wall coupling the corners of four 2D frame members.

[0092] The sixth embodiment of a block-like node member is a one-side additional opposite-faces truncated node 250 wherein additionally a side face is truncated 250. This node corresponds also to a portion of the full-size cubic node 200 wherein two opposite faces and one side face are truncated. In Fig. 2 the top face, bottom face and one side face is absent. This truncation reduces the node’s height and width in the direction perpendicular to the faces , eliminating the four threaded holes at the edges of each truncated face, resulting in at most two edges, each provided with a threaded hole. When 2D frame members are coupled to the one-side opposite-face truncated node via their notched corners, with bolts engaging the threaded holes, the truncated top, bottom face and side face align flush with the faces of the attached 2D frame members, ensuring a smooth, level surface. This node can be utilized at a free edge of a partition wall below the sheathing to connect two 2D-frame members.

[0093] A seventh embodiment of a node is a four faces truncated node 260. This embodiment corresponds to the full size node wherein the top and bottom face and additionally two adjacent side faces are truncated. A four-faces-truncated node 260 comprises only one edge with a threaded hole. This node can be utilized at a free corner of a partition wall below the sheathing.

[0094] An eighth embodiment of a node is a first variant of a composite node 270. The overall dimensions of composite node 270 correspond to those of the full-size node 200. Composite node 270 comprises a body part 271 of a first type and an add-on part 272. The body part 271 has the same length, and width as a full-size node and is nearly identical to the one-face truncated node 210. The main difference lies in the size of the recess 273 in the truncated face. Additionally, the through hole 275 in the body part 271 is a threaded through hole. The add-on part 272 comprises one face, visible as the top surface in Fig. 2, and includes plain chamfered surfaces 205 of four edges of the composite node 270. Each of the four edges comprises a threaded hole 201. In addition, the add-on part features a small, elongated striped surface 277 along the four chamfered surfaces. Each striped surface corresponds to a section of the side faces of the composite node 270. The function of this striped surface 277 will be described later.

[0095] The add-on part 272 further includes a counterbore through hole 276, preferably with a hexagonal cross-section, designed to fully accommodate a hexagonal nut 35, preventing it from rotating within the recess. The counterbore through hole 276 is unthreaded.

[0096] The add-on part 272 further comprises a protrusion 274 that fits rotationally into the recess 273 of the body part 271. This protrusion is essential for providing sufficient thread engagement length of a bolt in the threaded holes 201 , enabling them to withstand the forces applied when a 2D frame member is fastened to the add-on part using a bolt. The height of the protrusion determines the maximum allowable depth of the threaded holes.

[0097] When the small, elongated striped surfaces 277 of the add-on parts 272 are aligned with the corresponding side faces of the first type body part 271 , the composite node 270 has the same properties for coupling corners of 2D frame members as a full- size cubic node 200.

[0098] This type of composite node is particularly useful when the layout of a floor needs to be adjusted — for example, when repositioning / replacing partition walls or installing walls at an angle. A spacer 34 may be used to provide the necessary clearance for assembly of the structural elements in such cases. An Allen screw 33 may be used to fasten the add-on part 272 to the body part 271.

[0099] A ninth embodiment of a node is a second variant of a composite node 280. This composite node 280 comprises a second type body part 281 and an add-on part 171 , as described previously. The body part 281 is nearly identical to the opposite-face truncated node 240. The main difference lies in the dimensions of the recesses in the truncated faces. The recesses 283 in the second type body part have the same dimensions as the recess 273 in the truncated face of the body part 271 of the first variant of a composite node 270.

[0100] The second type body part 281 includes an unthreaded through hole 285. An Allen screw, in combination with a hexagonal nut 35 placed in the hexagonal recess 276 of the add-on part 272, can be used to couple the body part 281 to the add-on part 272. The distance between the truncated faces corresponds preferably to the thickness of the 2D-frame members.

[0101] When the small, elongated striped surfaces 277 of the add-on parts 272 are aligned with the corresponding side faces of the second type body part 281 , the composite node 280 has the same properties for coupling corners of 2D frame members as a one-face truncated node 210.

[0102] A tenth embodiment of a node is a third variant of a composite node 290. This composite node 290 consists of a second type body part 281 and two add-on parts 272. An Allen screw, in combination with a hexagonal nut 35 placed in the hexagonal recess 276 of one of the add-on parts 272, may be used to couple the body part 281 to the two add-on parts 272, thus forming the tenth embodiment.

[0103] When the small, elongated striped surfaces 277 of the add-on parts 272 are aligned with the corresponding side faces of the second type body part 281 , the composite node 290 has the same properties for coupling corners of 2D frame members as a full-size cubic node 200.

[0104] The 2D frame members according to the present invention are rectangular frames with a predefined thickness, length and width. The 2D frame members have a rectangular-like perimeter having notched corners. Each notched corner comprises a recess designed to receive an edge of a node with a threaded hole, aligning the node with the 2D frame when the edge is received in the recess. Additionally, each notched corner is provided with a mounting structure for attaching the 2D frame members to a node by means of a bolt, such that the edge of the node having the threaded hole is drawn into the recess by means of the bolt, coupling them together. The alignment is such that the faces of the node are parallel or perpendicular to side edges and faces of the 2D frame member.

[0105] The 2D-frame members consist of multiple components. In this application, two types of 2D-frame members are disclosed: a first type, comprising two parallel rectangular plates, and a second type, comprising U-shaped profiles.

[0106] Fig. 3 illustrates two exemplary embodiments of the first type of 2D frame members, each comprising two parallel rectangular plates 302, 302A. The term “Sandwich girders” in the present description refers to 2D frame members composed of two parallel plates. The difference between the two embodiments lies in the height of the plates. The rectangular plates 302 are interconnected by spacer elements in the form of two-way connectors 530. The notched corners of the rectangular plates are provided with a recess 306 for receiving and accommodating an edge of a node, which includes a threaded hole. The edges of the rectangular plates may further comprise one or more edge recesses 308 for receiving the face of a node. These recesses are arranged along the edges such that the distance between adjacent nodes — whether attached along the edge or at the corners of the 2D frame member, is a multiple of a predefined Baseline Unit (BU).

[0107] The BU is a design parameter used to define the Cartesian coordinates P(x, y, z) of nodes within the 3D design space, where the coordinates x, y, and z are expressed in units of the BU. The predefined BU is preferably in the range of 25 mm to 75 mm, and in particular, may be selected from the group comprising: 25 mm, 30 mm, 31.25 mm, 37.5 mm, 50 mm, 60 mm, 62.5 mm, 75 mm, 1.125 inch, 1.1875 inch, 1.25 inch, 1.5 inch, 2.25 inch, 2.375 inch, 2.5 inch, and 3 inch. By using a predefined BU, each possible node position in the modular construction system corresponds to a grid point in a 3D Cartesian planar grid, where the spacing between grid points in the x-, y-, and z-directions is a predefined multiple of the BU.

[0108] Openings 310 are provided at the notched corners for inserting a unthreaded plug 520a enabling to screw a bolt at an angle of 45 degrees with respect to the side edges into a threaded hole of a node. The bolt and the unthreaded plug form a mounting structure with a through-hole for securing the 2D-frame member to a node.

[0109] On either side of each edge recess 308, additional openings 311 and 313 are provided for inserting an unthreaded plug 520a, enabling a node to be attached at the corner using a bolt angled at 45 degrees. An additional opening 312 is provided to receive either a threaded plug 520 or an unthreaded plug 520A for attaching a node to the edge of the 2D frame member. The threaded plug 520 is used when a bolt is first inserted into an unthreaded hole 204 of the node and subsequently screwed into the threaded opening of the plug. The unthreaded plug 520A is used when the bolt is first inserted into the plug and then screwed into a threaded hole in the face of a node.

[0110] Opening 324 may be used to facilitate insertion of a bolt between the two plates in order to connect a node positioned in a recess 308 to the 2D frame member, by screwing the bolt into a threaded hole 202 in the face of the node.

[0111] The rectangular plates 302 included a protruding edge section 320 between corner recess 306 and edge recess 308, and between edge recesses 308. The protruding edge section 320 are provided with a fixing hole 322, which allows a U-profile to be secured directly to the rectangular plate. This is accomplished by inserting a self-tapping screw through a corresponding opening 414 in the bottom of the U-profile and driving the self-tapping screw into the fixing hole 322. The rectangular plates 302 are further provided with hole patterns consisting of sheathing holes 342 and 344, which are used to attach sheathing strips and sheathing plates, respectively, to the face of the 2D frame member.

[0112] Fig. 4 illustrates three U-profiles of different length, which are used to assemble the second type of 2D-frame members.

[0113] Each U-profile comprises a flat bottom portion 402 with two upright flanges 404 extending from opposite sides, together forming a U-shaped cross-section. In the assembled 2D frame member, the flat bottom faces outward and the flanges extend inward. As a result, the bottom defines the outer edge of the 2D frame, while each flange forms part of one of the two main faces of the 2D frame member.

[0114] Each upright flange 404 is provided at its free end with a bevelled edge inclined at 45 degrees relative to the flat bottom 402, such that the bevelled ends taper into a point directed toward the bottom. At the transition between at least one bevelled end and the bottom, a cut-out 406 is provided. When two U-profiles are joined at their ends, the respective cut-outs together form a corner recess of a 2D frame member. This recess is configured to accommodate an edge of a node containing a threaded hole and to enable proper alignment of the node’s faces with the adjacent faces and edges of the 2D frame member when a bolt is fastened.

[0115] An additional cut-out 410 at the bevelled edge is provided to form a support surface for a fixing plate 510.

[0116] The flat bottom 402 also comprises one or more node recesses 408 along its edges, each shaped to accommodate the face of a node. These recesses are distributed along the bottom such that the distance between nodes mounted along the edge of the U-profile — including those at the corners of the 2D frame member — is a multiple of the predefined Baseline Unit (BU) value.

[0117] A mounting recess 412 at the free edge of the two flanges 404, opposite recess 408 in the flat bottom 402, is configured to receive a fixing plate 510, which when placed in the recess forms the mounting structure that includes a through-hole and a bolt, allowing the 2D-frame member to be secured to the 2D frame member to a block-like node element by means of a bolt.

[0118] Additionally, the bottom 402 is provided with two or more mounting holes 434, spaced apart between recesses 406 and 408 at intervals equal to or corresponding to a multiple of the predefined BU value. These holes are intended for attaching folded strip brackets 560 or 570 to the inner side of the U-profile and for mutual attachment using connectors 530 and 540. Each flange of the U-profile is further provided with: bracket mounting holes 432, for securing additional components; and first and second sheathing mounting holes 442 and 444, which form a mirrored, symmetrical, and repeated pattern along the edges of the 2D frame member.

[0119] This hole pattern is configured to match the corresponding hole pattern of prefabricated sheathing panels and sheathing strips, thereby ensuring secure attachment of the sheathing elements to the frame. The axis of symmetry for this pattern is perpendicular to the flat bottom 402 and passes through the centre of a node recess 408.

[0120] The first sheathing mounting holes 442 are intended for mounting sheathing strips, while the second sheathing mounting holes 444 are intended for mounting sheathing panels to the 2D frame member.

[0121] It should be noted that a structure comprising four U-profiles forming the edges of a 2D frame member may alternatively be formed by folding a single sheet or plate.

[0122] The nodes and 2D frame members are structural elements of the modular building system according to the present disclosure. These structural elements are preferably made of steel, which allows for high-precision and high-volume manufacturing using modern fabrication techniques such as laser cutting and CNC machining.

[0123] Steel offers several advantages over alternative materials: it is strong, relatively inexpensive to produce, and increasingly manufactured using environmentally friendly processes. Additionally, steel can be treated to resist corrosion and is capable of withstanding extreme temperatures, making it particularly suitable for use in structural elements of a high-definition modular building system as described herein.

[0124] In certain applications, alternative materials such as stainless steel or aluminium may also be used, depending on specific design requirements or environmental conditions.

[0125] Fig. 5 illustrates parts used to assemble 2D frame members and coupling components.

[0126] Fixing plate 510 is a small plate with a central hole 514, designed to be placed either in the mounting recess 412 or on the support surface formed by the additional cut-outs 410 of two U-profiles joined to form an edge of a 2D frame member. The fixing plate 510 includes two protrusions 512 on two opposite edges, which create spaces that accommodate portions of the flanges of the U-profiles. These protrusions act to restrict outward deflection or spreading of the flanges under load. This ensures that the fixing plate remains securely positioned, even when an Allen screw or Hex or hex bolt is inserted through its central hole and tightened into a threaded hole of a node element. The resulting assembly ensures a stable and secure connection between the 2D frame member and the node.

[0127] Threaded plug 520 may be used to connect a node positioned in a recess 308 of a 2D frame member composed of two parallel rectangular plates. The threaded plug 520 comprises a cylindrical body with one flattened side, which is provided with a threaded through-hole 524, the central axis of which is oriented perpendicular to the flattened surface. The flattened side ensures correct alignment and positioning of the plug within the corresponding openings 312 of the two parallel rectangular plates.

[0128] Preferably, the plug includes a fully cylindrical end 526, which serves as a stop to prevent the plug from being pushed too far through the combined hole structure formed by the two aligned openings in the rectangular plates.

[0129] In addition, two grooves 522 are provided on the cylindrical portion with the flattened side. These grooves are designed to engage with portions of the edges of the openings when the threaded plug is pushed in the direction of recess 308, as the node is secured in place by tightening an Allen screw (or hex bolt) inserted through the unthreaded hole 204 of the node and screwed into the threaded hole 524 of the plug. The grooves prevent axial displacement of the plug after the node is mounted, thereby preserving the mechanical integrity of the connection between the node and the 2D frame member.

[0130] Unthreaded plug 520a differs from threaded plug 520 in that it includes an unthreaded through-hole 524a. The unthreaded plug shares the same general structure, comprising a cylindrical body with one flattened side, a fully cylindrical end 526a, and two grooves. When inserted into one of the openings 310, 311 , 312, or 313, the unthreaded plug can be used to connect a node positioned in a recess 306 or 308 of a 2D frame member by inserting a bolt or an Allen screw through the unthreaded hole 524a and tightening it into a threaded hole at the edge or face of a node.

[0131] 2-way connector 530 has a length corresponding to the distance between two parallel rectangular plates of a 2D frame member and functions as a spacer between these plates. The 2-way connector is provided with a threaded through hole, allowing the connector to be secured to the rectangular plates. This is achieved by inserting a threaded fastening element (such as a screw or bolt) through a corresponding opening in the rectangular plate and tightening it into the threaded hole at the end of the 2-way connector. 2-way connector 530A is longer than 2-way connector 530 and has a length corresponding to the thickness of a 2D frame member. It is used to couple the flat bottoms of U-profiles of adjacent 2D frame members. This coupling is achieved by inserting a threaded fastening element (such as a screw or bolt) through a corresponding opening in the bottom of a U-profile and tightening it into the threaded hole at the end of the 2-way connector 530A.

[0132] Universal connector 540 is a block-like element with a length and width corresponding to the thickness of a 2D-frame member, and a height corresponding to the distance between the two parallel plates forming the 2D-frame member.

[0133] The universal connector comprises two threaded through-holes 544, each having a central axis passing through the centres of two opposite faces, perpendicular to those faces, and one unthreaded through-hole 544a, having a central axis passing through a third pair of opposite faces.

[0134] The threaded through-holes 544 have a length corresponding to the thickness of the 2D-frame members, while the unthreaded through-hole 544a has a length corresponding to the distance between the parallel plates of the 2D-frame member.

[0135] Universal connector 540 can be used to connect the flat bottoms of two, three, or four U-profiles of adjacent 2D-frame members. It can also be used as a replacement for the 2-way connector 530, for coupling two parallel rectangular plates.

[0136] Corner bracket 550 is an element to couple the ends of U-profiles to form a notched corner of a 2D-frame member. A corner bracket is attached to the inner side of each of the flange 404 of a U-profile by driving self-tapping screws in the fixing holes 552.

[0137] Double folded strip bracket 560 is configured to be mounted on the inner side of the flat bottoms of two U-profiles in order to form a notched corner of a 2D-frame member. The bracket comprises a central middle section 562 and two attachment sections 564 located on opposite sides of the middle section. Each attachment section is folded at an angle of 45 degrees with respect to the middle section, and the two attachment sections are oriented perpendicularly to one another.

[0138] The middle section 562 is provided with an elongated opening 566, which allows it to be fastened to a threaded hole at the edge of a node using an Allen screw or similar fastener. Each of the attachment sections 564 comprises two mounting holes 568, which are used to secure the bracket to the inner side of the flat bottom of a U-profile by means of bolts and nuts or other suitable fasteners.

[0139] Single folded strip bracket 570 is configured to be mounted on the inner side of the flat bottom of a single U-profile, in order to couple a node positioned in a recess 408 of the U-profile to the U-profile. The bracket comprises a node attachment section 572 and a U-profile attachment section 574 extending from one side of the node attachment section. The U-profile attachment section is folded at an angle of 45 degrees relative to the node attachment section.

[0140] The node attachment section 572 is provided with an elongated opening 576, allowing the bracket to be fastened to a threaded hole at an edge of a node using an Allen screw or similar fastener. The U-profile attachment section 574 comprises two mounting holes 578, which are used to secure the bracket to the inner side of the flat bottom of a U-profile by means of bolts and nuts or other appropriate fastening elements.

[0141] Both the Double folded strip bracket and the Single folded strip bracket have a width corresponding to the width of the inner side of the flat bottom of a U-profile, ensuring a precise fit and stable mounting within the profile.

[0142] Fig. 6 illustrates a cross-sectional view of the coupling of three different embodiments of 2D frame members to a block-like node member.

[0143] Fig. 6 shows a horizontally oriented threaded through-hole 202, the central axis 604 of which coincides with a 4-fold symmetry axis of the node, and a vertically oriented unthreaded counterbore hole 203, the central axis 604a of which coincides with another 4-fold symmetry axis of the node.

[0144] The node is a full-size cubic node 200, as shown in Fig. 2. A 2D frame member constructed from two parallel rectangular plates 302 is attached to the lower right edge of the node 200. The corner of the 2D frame member is connected to the node by first positioning an unthreaded plug 520a in the corresponding openings 310 of the two parallel rectangular plates 302, thereby forming a mounting structure with a through-hole. Subsequently, a bolt 32 is inserted through the unthreaded opening of plug 520a and tightened into a threaded hole located at the chamfered edge of the node. The central axis of this threaded hole coincides with a 2-fold symmetry axis 602a of the node.

[0145] By tightening bolt 32, the chamfered edge of the node is drawn into the recess formed by the two parallel rectangular plates 302, and the two bearing surfaces 620 and 622 of the recess are pressed against two adjacent faces of the node. This configuration aligns the node and the 2D frame member such that the node’s faces are oriented parallel or perpendicular to the side edges and faces of the 2D frame member.

[0146] A 2D frame member constructed from U-profiles 400, whose ends are coupled by corner brackets 550, is attached to the upper right edge of the node 200. The corner of the 2D frame member is connected to the node by first positioning a fixing plate 510 in the corresponding opening between the two connected U-profiles and against the inward-facing side of the corner bracket, thereby forming a mounting structure with a through-hole. Subsequently, a bolt 32 is inserted through the unthreaded opening of the corner bracket 550 and tightened into a threaded hole located at the chamfered edge of the node. The central axis of this threaded hole coincides with another 2-fold symmetry axis 602 of the node.

[0147] By tightening bolt 32, the chamfered edge of the node is drawn into the recess formed by the ends of the two U-profiles that form the notched corner. The ends of the flat bottoms of the two U-profiles define two bearing surfaces 620a and 622a of the recess, which are pressed against two adjacent faces of the node. This configuration serves to align the node and the 2D frame member such that the faces of the node are oriented parallel or perpendicular to the side edges and faces of the 2D frame member.

[0148] A 2D frame member constructed from U-profiles 400, whose ends are coupled by double folded strip bracket 560, is attached to the upper left edge of the node 200. Each of the two attachment section is coupled to a bottom of the U-profile using a bolt and nut. The double folded strip bracket 560 forms the mounting structure with a through-hole. Subsequently, an Allen screw 33 is inserted through the elongated opening 566 in the middle section of the corner bracket 550 and tightened into a threaded hole located at the chamfered edge of the node.

[0149] By tightening Allen screw 33, the chamfered edge of the node is drawn into the recess formed by the ends of the two U-profiles that form the notched corner. The ends of the flat bottoms of the two U-profiles define two bearing surfaces 620b and 622b of the recess, which are pressed against two adjacent faces of the node. This configuration also serves to align the node and the 2D frame member such that the faces of the node are oriented parallel or perpendicular to the side edges and faces of the 2D frame member.

[0150] Figure 6A illustrates the dimensional relationship between truncated nodes and 2D frame members in the modular building system. The figure shows a composite node 290, comprising a body part 281 and two optional add-on parts 272. The composite node has a length, width, and height of C. The body part 281 has a length and width of C and a height F, which corresponds to the width of a U-profile 400 of a 2D frame member. Each add-on part 272 also has a length and width of C and, when attached to a truncated face of body part 281 or of another body part 271 , increases the total height of the resulting composited node by (C-F) / 2, a dimension denoted as T in Figure 6A.

[0151] A truncated face of the body part 281 that is not provided with an add-on part is aligned flush with a face of the U-profile 400. As used in the application, the plane of a truncated face of a truncated node corresponds to the plane of a face of a full-size cubic node from which a layer of material of thickness T has been removed. This configuration ensures flush alignment, simplifies cladding, and enhances versatility for structural applications.

[0152] Accordingly, a one-face truncated node 210 has a length and width of C, and a height of (C-T). A two-adjacent-faces truncated node 220 has a length of C and a width and height of (C-T). A three-adjacent-faces truncated node 230 has a length, width and height of (C-T). An opposite-faces truncated node 240 has a length and width of C, and a height of (C-2T), which is equal to F. A one-side additional opposite-faces truncated node 250 has a length of C, a width of (C-T), and a height of (C-2T). A four faces- truncated node 260 has a length and width of (C-T) and a height of (C-2T). Finally, body part 271 has a length and width of C, and a height of (C-T).

[0153] Figure 6A also clearly illustrates the elongated striped surfaces 277 adjacent the chamfered surfaces of the add-on part, against which one of the bearing surfaces 620 or 622 of the recess at a notched corner of a 2D frame member is pressed when the 2D frame member is attached to the chamfered edge of the add-on part. The elongated striped surfaces 277 of the add-on parts, together with an aligned face of the body part 281 form one continuous face of a full-size cubic node.

[0154] Fig. 7A shows a two part composite full size node 270 as depicted in Fig. 1 , featuring first-type edges. The full edges of the node are chamfered

[0155] Fig. 7B illustrates a side view of a recess in a notched corner of a 2D frame member, complementary to the first-type edge shown in Fig. 7A. The complementary recess of the notched corner is configured to match the chamfered edge. This recess comprises a first bearing surface 720, which forms a straight edge with side 726 of the 2D frame member, a second bearing surface 722, which forms a straight edge with side 728 of the 2D frame member, and an intermediate surface 724 located between the two bearing surfaces.

[0156] The notched corner is mirror-symmetrical with respect to axis 730. The intermediate surface has a width corresponding to the width of the elongated surface of the chamfered edge.

[0157] Fig. 7C provides a side view showing how the recess in a notched corner of a rectangular plate of a 2D frame member fits the truncated edge of a corresponding node. Fig. 7D provides a side view of the recess in a notched corner of a 2D frame member formed by coupling the ends of two U-profiles by means of bracket 550. It illustrates how the recess aligns with the truncated edge of a node.

[0158] Both Figs. 7C and 7D clearly show that the two bearing surfaces 720 and 722 — whether formed by two parallel plates or by coupled U-profiles — are in contact with adjacent faces of the node. This contact enables precise alignment of the node such that its faces are oriented parallel or perpendicular to the faces and side edges of the 2D frame member. Furthermore, figure 7D shows that the bearing surfaces 720 and 722 of the 2D frame member, which is coupled to the add-on part of the two-part composite full- size node 270, make contact only with faces of the add-on part and not with any face of the body part. Additionally, the side edge of the attached 2D frame member is aligned with the truncated face of the body part. This configuration enables the attachment of a notched corner of a 2D frame member to the add-on part regardless of the orientation of the add-on part relative to the body part.

[0159] Fig. 8A illustrate a two part composite full-size node with second-type edges. In this design, a chamfer is applied only around the threaded hole to facilitate the positioning of a bolt in the threaded hole.

[0160] Fig. 8B illustrates a side view of a recess in a notched corner of a 2D frame member, complementary to the first-type edge shown in Fig. 8A. The complementary recess of the notched corner is configured to match the chamfered edge. This recess comprises a first bearing surface 820, which forms a straight edge with side 826 of the 2D frame member and a second bearing surface 822, which forms a straight edge with side 828 of the 2D frame member. There is no intermediate surface located between the two bearing surfaces. The notched corner is mirror-symmetrical with respect to axis 830.

[0161] Fig. 8C provides a cross-sectional view showing how the recess in a notched corner of a rectangular plate of a 2D frame member fits the truncated edge of a corresponding node.

[0162] Fig. 8D provides a cross-sectional view of the recess in a notched corner of a 2D frame member formed by coupling the ends of two U-profiles by means of bracket 550. It illustrates how the recess aligns with the truncated edge of a node.

[0163] Both Figs. 8C and 8D clearly show that the two bearing surfaces 820 and 822 — whether formed by two parallel plates or by coupled U-profiles — are in contact with adjacent faces of the node.

[0164] Fig. 9A illustrate a two part composite full-size node with third-type edges. In this design, the chamfer along an edge comprises three regions. The middle region 910 features a chamfer similar to the chamfer of the second-type edge shown in Fig. 8A. The other two adjacent regions 912 are less chamfered than the middle region 910.

[0165] Fig. 9B illustrates a side view of a recess in a notched corner of a 2D frame member, complementary to the first-type edge shown in Fig. 9A. The complementary recess of the notched corner is configured to match the chamfered edge of the adjacent regions 912. This recess comprises a first bearing surface 920, which forms a straight edge with side 926 of the 2D frame member and a second bearing surface 922, which forms a straight edge with side 928 of the 2D frame member. There is an intermediate surface located between the two bearing surfaces which is smaller than that of the first type edges. The notched corner is mirror-symmetrical with respect to axis 930.

[0166] Fig. 9C provides a cross-sectional view showing how the recess in a notched corner of a rectangular plate of a 2D frame member fits the truncated edge of a corresponding node.

[0167] Fig. 9D provides a cross-sectional view of the recess in a notched corner of a 2D frame member formed by coupling the ends of two U-profiles by means of bracket 550. It illustrates how the recess aligns with the truncated edge of a node.

[0168] Both Figs. 9C and 9D clearly show that the two bearing surfaces 920 and 922 — whether formed by two parallel plates or by coupled U-profiles — are in contact with adjacent faces of the node.

[0169] Fig. 10A illustrates a structure in which three 2D frame members 440 composed of U-profiles 400 are interconnected using nodes 200 at notched corners. Universal connectors 540 are employed to couple the flat bottoms of adjacent U-profiles that together form an edge of the structure. The corner brackets 550 are secured to the inner surfaces of the U-profile flanges by means of self-tapping screws 37.

[0170] Fig. 10B shows a cross-sectional view of the connection between two adjacent 2D frame members that are positioned perpendicular to each other. In this configuration, the universal connector 540 is attached to a flat bottom of each of the adjacent U-profiles by means of a bolt 32 which is screwed into one of the threaded holes of the universal connector.

[0171] Fig. 11 A illustrates a structure in which three 2D frame members composed of parallel rectangular plates 302 are interconnected using nodes 200 at notched corners. Universal connectors 540 are employed to couple the parallel rectangular plates 302 that together form an inner edge of the structure.

[0172] Fig. 11 B shows a cross-sectional view of the connection between two adjacent 2D frame members positioned perpendicular to each other. In this configuration, the universal connector 540 is attached to the outer faces of the parallel rectangular plates 302 by means of a bolt 32, which passes through corresponding aligned openings in both plates and is tightened into one of the threaded holes of the universal connector. A cylindrical spacer 36 is positioned between the plates to maintain the correct spacing between the plates while the bolt 32 is fastened.

[0173] Fig. 12 shows a first embodiment of coupling U-profiles to form a truncated corner of a 2D frame member and coupling the corner to a middle part 281 of a three part composite full-size node. In Fig. 12 ends of U-profiles are coupled by a two folded strip bracket 560.

[0174] Fig. 13 illustrates a second embodiment for coupling U-profiles to form a truncated corner of a 2D frame member and for connecting the corner to a middle part 281 of a three-part composite full-size node. In this embodiment, the ends of the U- profiles are joined using two corner brackets 550, which are mounted on the inner sides of the flanges of the U-profiles.

[0175] Fig. 13 further demonstrates how a node can be connected to the side of a U-profile by means of two single folded strip brackets 570, positioned on either side of the recess in the bottom of the U-profile.

[0176] Additionally, Fig. 13 shows how a double folded strip bracket can be used to attach U-profiles 1400 with straight ends — intended for placement between two opposite U-profiles of a 2D frame member — without the use of a node.

[0177] Finally, the figure illustrates the use of a 2-way connector 530a to couple the bottom sides of adjacent U-profiles.

[0178] Fig. 14 illustrates a diagonal connection of a 2D frame member using composite nodes 270. In this figure, the horizontally oriented 2D frame member is composed of two types of U-profiles: two opposite U-profiles that allow nodes to be attached at a mutual spacing of 3BU, and two opposite U-profiles that allow nodes to be attached at a mutual spacing of 4BU.

[0179] The diagonally and perpendicularly attached 2D frame member is composed as follows: in the diagonal direction (horizontal in Fig. 14), two U-profiles allow nodes to be attached at a mutual spacing of 5BU, and in the vertical direction (as seen in Fig. 14), two U-profiles also allow nodes to be attached at a mutual spacing of 5BU.

[0180] Fig. 15 shows a detailed view from Fig. 14, highlighting the orientation of the add-on part 272 relative to the body part 271 of the composite node. It also illustrates the formation of a notched corner of the diagonally connected 2D frame 1410. This corner is created by connecting the ends of two U-profiles using two corner brackets 550. The corner brackets are affixed to the add-on part 272 via a fixing plate 510. The flanges of the fixing plate 510 are secured in corresponding recesses formed by the U-profiles forming the notched corner against the corner bracket, and a bolt 32 is used to complete the attachment. The other 2D frame member 1420 is connected to the body part 271 in a similar manner.

[0181] Figs. 16 illustrates the incorporation of infrastructure within the building structure. 2D frame members composed of two parallel rectangular plates 302, forming girders for floors and ceilings are preferably equipped with holes to allow the passage of piping 2020, cable trays 2010, and other utility lines. In general, 2D frame members provide passageways for utility lines.

[0182] The gap between two parallel rectangular plates 302 forming a girder, the flanges of U-profiles 2007 is sufficient for utility lines 2000 to pass through. As depicted, a flexible electrical conduit 2000 or any other utility line exits a cable tray 2010 horizontally, travels between the two rectangular plates 302, bends upward into a recess at the bottom of a U-profile, and then passes through the gap between the flanges of the U-profile further upwards.

[0183] A suspension bracket 80 is mounted to the girder at the bottom side of a hole in the girder, supporting the cable tray 2010. Another suspension bracket 80 is mounted at the top side of another hole in the girder. A pipe hanger or pipe clamp 2030 secures the piping 2020 to the suspension bracket, ensuring that the piping does not rest on the relatively sharp edges of the girder hole.

[0184] Fig. 17, a detail of Fig. 16, shows a construction where six notched corners of 2D frame members are coupled to a single two-part composite node 270.

[0185] Fig. 18 shows a cross sectional view of the construction shown in Fig. 17. It shows how a protruding edge section 320 may be used to couple a bottom of a U-profile direct to a rectangular plate 302. This is accomplished by inserting a self-tapping screw through a mounting hole 434 in the bottom of the U-profile and driving the self-tapping screw into the fixing hole 322 of the protruding edge section. Mounting holes 434 has preferably a diameter larger than the threaded portion of the self-tapping screw, ensuring the screw cuts only into the fixing hole 322.

[0186] Fig. 19 illustrates a configuration of the modular building system, forming a building framework with box-shaped load-bearing components 1902 and wall structures 1904. Box shaped load-bearing components can be in the form of manifolds and beams. Each side of a box-shaped load-bearing component is made from a 2D-frame member composed of two parallel rectangular plates 300 which are coupled at their notched corners with block-like node members as described before. A manifold is a cubical loadbearing component configured to connect columns 1910 with beams. Fig. 19 shows two horizontal beams coupled to a manifold. Sandwich girders 1906 are provided between the horizontal beams to form secondary joists support structure to provide a support structure for a floor. A box-shaped load bearing component is coupled vertically on top of the manifold. A column 1910 is located in the vertical load bearing component and coupled at its lower end to the manifold. The wall structures 1904 are formed by 2D frame members 440 constructed from U-profiles, which provide the rectangular perimeter. Truncated nodes 220, 271 , 281 may be used to provide a frame work with flat surfaces.

[0187] The obtained frame work allows to attach standard cladding panels 2010 and cladding strips 2020 to cover the outer surface of the frame work as shown in Fig 20.

[0188] The arrangement, as depicted, demonstrates the modular building system’s ability to combine robust, box-shaped beams or columns with U-profile-based walls, providing dimensional accuracy, ease of assembly, and versatility for diverse structural applications.

[0189] The modular building system enables the construction of a raised floor and associated walls within an existing building, enhancing adaptability for retrofitting applications. The raised floor is formed by 2D frame members, each constructed from U- profiles with corner brackets to create a rectangular perimeter and notched corners, coupled via block-like node members . Each node member, equipped with height- adjustable feet on its underside, supports the 2D frame members, allowing precise levelling and elevation above the existing floor. The coupling occurs at the notched corners, where a recess receives an edge of a node member, and a bolt passes through a mounting structure with a through hole to engage a threaded hole at the node’s edge, ensuring a rigid, slack-free connection with faces aligned parallel or perpendicular to the frame’s side edges and faces. The space between the existing floor and the raised floor accommodates utility lines, such as electrical or plumbing conduits. Walls are formed by additional 2D frame members, also constructed from U-profiles, directly attached to the block-like node members of the raised floor via their notched corners and threaded holes, ensuring flush alignment and structural integrity. This configuration facilitates easy installation of a dimensionally accurate framework, suitable for cladding with standard cover plates and adaptable to various building requirements.

[0190] Disclosed is a lightweight and high-resolution modular building system, versatile and designed for easy assembly, disassembly and adaptability of building structures. This is the way forward, provided the materials used are derived from sustainable sources and each and every part of this building system can be used many times without limitations or generation of waste.

[0191] The hybrid 3D structural building system, primarily made of steel and sheathed with structural panels made of CLT / Multiplex or any other sustainable material, helps to reach goals where “zero-waste-adaptability” of even the smallest structural parts is key in reaching the highest degree of circularity and sustainability.

[0192] While the invention has been described in terms of several embodiments, it is contemplated that alternatives, modifications, permutations and equivalents thereof will become apparent to those skilled in the art upon reading the specification and upon study of the drawings. The invention is not limited to the illustrated embodiments. Changes can be made without departing from the scope of the appended claims.

Claims

CLAIMS:

1. Modular building system comprising frame members and block-like node members forming a building framework, characterized in that: the block-like node members include full-size cubic nodes and truncated nodes; wherein each full-size cubic node is provided with a threaded hole at the midpoint of its twelve edges, the threaded holes having a central axis coinciding with 2-fold symmetry axes passing through the midpoints of opposite edges of the cubic node, and each edge is configured to couple to a notched corner of a 2D frame member; optionally each full-size cubic node is provided with through holes each having a central axis coinciding with 4-fold symmetry axes passing through the centre of opposite faces of the cubic node; wherein each truncated node comprises a portion of a full-size cubic node with one, two, three, or four truncated faces, corresponding a full-size cubic node of which one, two, three or four faces are truncated by removing a layer of material from said one or more faces resulting in the truncated faces, thereby reducing the number of its twelve edges provided with a threaded hole; wherein the 2D frame members have a rectangular perimeter and a thickness less than the length of an edge of a cubic node, with notched corners each having a recess configured to receive an edge of a block-like node member; each notched corner is provided with a mounting structure with a through-hole for securing the 2D frame member to a block-like node element by a bolt engaging the threaded hole, the recess of the notched corner providing two bearing surfaces that abut the two faces adjacent to the edge of the block-like node member that is coupled to the 2D frame member, aligning the node and 2D frame member such that the node’s faces are parallel or perpendicular to the frame’s side edges and faces.

2. The modular building system according to claim 1 , wherein the recess at each notched corner of the 2D frame member is mirror-symmetrical with respect to a diagonal plane bisecting the corner, and wherein the two bearing surfaces of the recess are mutually perpendicular.

3. The modular building system according to claim 1 or 2, wherein each edge of the block-like node members provided with a threaded hole is chamfered at least around the threaded hole, wherein the chamfer forms a surface perpendicular to the central axis of the threaded hole.

4. The modular building system according to claim 3, wherein the chamfer extends along the entire5. The modular building system according to any of the claims 1 - 4, wherein each truncated node is configured such that the truncated face(s) lie flush with the faces of the 2D frame members attached thereto, aligning the truncated face(s) of the truncated node with the side surfaces of the 2D frame members in the building framework.

6. The modular building system according to any of the claims 1 - 5, the block-like node members further include two part composite full-size nodes, each comprising: a body part and an add-on part, the body part corresponding to a portion of a full-size cubic node with one truncated face, the body part having a recess in the truncated face and a threaded through hole in the centre of the truncated face an perpendicular to the truncated face, and an add-on part corresponding to a missing portion of the body part to obtain a full-size cubic node, the add-on part comprising one face and four edges, each edge provided with a threaded hole corresponding to a threaded hole at an edge of a full-size cubic node, the add-on part further comprising an unthreaded counterbore through hole, and a protrusion configured to fit rotationally into the recess of the body part; wherein the body part and the add-on part are coupled by a bolt in the counterbore through hole of the add-on part engaging the threaded through hole of the body part.

7. The modular building system according to any of the claims 1 - 6, wherein the block-like node members further include three part composite full-size nodes, each comprising: a middle body part and two add-on parts, the middle body part corresponding to a portion of a full-size cubic node with two opposite faces truncated, the middle body part having a recess in each the truncated faces and an unthreaded through hole in the centre of the truncated faces, and each of the add-on parts corresponds to a missing portions of the body part to obtain a face of a full-size cubic node, each add-on part comprising one face and four edges corresponding full-size cubic node, each edge provided with a threaded hole corresponding to a threaded hole at an edge of a full-size cubic node, the add-on part further comprising an unthreaded counterbore through hole, and a protrusion configured to fit rotationally into the recess of the body part;wherein the body part and the two add-on parts are coupled by an Allen screw engaging the unthreaded through hole of the body part and the hexagonal nut in the counterbore through hole of one of the add-on parts.

8. The modular building system according to any of the claims 1 - 7, wherein one or more 2D frame members further comprises one or more recesses along its edges, each recess configured to accommodate a face of a block-like node member and opposite edges of said face, wherein opposite ends of the recess have a similar shape as the notched corners, each recess is provided with three mounting structures with a through- hole for aligning a block-like node member to an edge of the 2D frame member by one, two or three bolts engaging a corresponding threaded hole of the block-like node member.

9. The modular building system according to any of the claims 1 - 8, wherein one or more 2D frame members are composed of U-profiles and corner brackets, wherein the U-profiles form the rectangular perimeter of the 2D-frame member, at least one corner bracket is attached to corresponding an inner sides of ends of adjacent U-profiles to connect the ends of two adjacent U-profiles, forming a notched corner with a recess configured to receive an edge of a block-like node member.

10. The modular building system according to claim 9, the bearing surfaces of the recess of a notched corner formed by the connection of two adjacent U-profiles are defined by the end faces of bottoms of the adjacent U-profiles.11 . The modular building system according to any of the claims 1 - 10, wherein one or more 2D frame members are composed of two parallel, substantially rectangular plates, which are connected to each other with spacer elements, wherein corners of the rectangular plates are provided with the recess configured to receive an edge of a blocklike node member having a threaded hole and provide the bearing surfaces.

12. The modular building system according to any of the claims 1 - 11 , wherein the full-size cubic nodes have a length, width and height of C, the 2D-frame members have a thickness of F and the layer of material virtually removed from said one or more faces of the full-size cubic node, resulting in the truncated faces of a truncated node, has a thickness T which equals (C - F) / 2.

13. The modular building system according to any of the claims 1 - 12, wherein when two 2D frame members are coupled via their notched corners to opposite edges of a face of a block-like node member, the distance between facing parallel outer edges of the two 2D frame members corresponds to the thickness of a 2D frame member.

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