How to extend a building

Abstract

To provide a building extension method excellent at workability with which the number of exterior wall panels to be removed can be reduced as much as possible when constructing an extension part below a girth in an existing building where the outer wall panels protrude in front of the girth located therebelow.SOLUTION: Provided is a building extension method for removing a part of an outer wall 110 of a multi-story existing building 100 and extending it. The existing building 100 has outer wall panels 40A, 40B on an upper floor and a lower floor, respectively. The outer wall panel 40A on the upper floor protrudes in front of a girth 10A between the upper and lower floors. When carrying out extension on the outdoor side of the lower floor of the existing building 100, there are a process A of exposing a part of the girth 10A by cutting the outer wall panels 40A at least halfway in a height of the girth 10A of the outer wall panel 40A on the upper floor and reinforcing a cut part 40a, and a process B of connecting a ceiling beam 90 to the exposed girth 10A so as to construct an extension part 200.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a method for extending a building. [Background technology]

[0002] When constructing an extension to an existing building, a method is applied in which part of the exterior wall of the existing building is removed to expose, for example, the girt between floors, the ceiling beams of the extension are connected to the exposed girt, the foundation of the extension is connected to the foundation of the existing building, and the exterior wall panels are attached to the ceiling beams and foundation.

[0003] For example, in an existing two-story building, if the exterior wall panels are independent for each floor (if the exterior wall panel for the second floor fits above the girth between the first and second floors), when constructing an extension on the outside of the exterior wall of the first floor, it is sufficient to remove the exterior wall panel for the first floor to expose the girth between the first and second floors. On the other hand, in an existing building in which the exterior wall panel is configured so that it overhangs the front of the girth below it and the lower girth is installed in such a way that it is completely hidden by the exterior wall panel on the second floor, it is not possible to easily expose the girth as described above. This will be explained with reference to Figures 1 to 4.

[0004] Fig. 1 is an external perspective view showing an example of an extension constructed on an existing two-story building, Fig. 2 is a front view showing two upper and lower beams (eaves beam and girth) and an example of an exterior wall panel mounting bracket attached to each beam, and Fig. 3 is a perspective view of an example of an exterior wall panel seen from an oblique rear direction. Also, Fig. 4 is a front view showing a state in which the exterior wall panel shown in Fig. 3 is attached to the eaves beam and girth shown in Fig. 2 as an exterior wall panel for the second floor, and a separate exterior wall panel is further attached to the girth as an exterior wall panel for the first floor.

[0005] Fig. 1 shows an example in which a part of the exterior wall 110 of an existing two-story light-gauge steel-framed building 100 has been removed and an extension 200 with a cubic exterior shape has been constructed. In the example shown in Fig. 2, the lower beam 10A is a girder between the first and second floors, and the upper beam 10B is a eaves girder at the eaves ceiling, and both beams 10A and 10B are made of H-shaped steel. Two different types of exterior wall panel mounting brackets 20A and 20B are attached to each beam 10.

[0006] The exterior wall panel mounting bracket 20A, which is attached above the upper flange 11 of the girth 10A, has a fixed piece 21 fixed to the upper flange 11 of the girth 10A by a bolt 28, and an abutment piece 22 that abuts against the panel frame 44 of the exterior wall panel 40 perpendicular to the fixed piece 21, and the abutment piece 22 has a plurality of guide engagement grooves 23 (two in the illustrated example) opened at intervals.

[0007] On the other hand, the exterior wall panel mounting bracket 20B, which is attached below the lower flange 12 of the eaves beam 10B and the girder 10A, has a fixed piece 24 fixed to the lower flange 12 by a bolt 28, and an abutment piece 25 that abuts against the panel frame 44 of the exterior wall panel 40 perpendicular to the fixed piece 24, and the abutment piece 25 has multiple bolt holes 27 (two in the illustrated example) opened in it.

[0008] As shown in Fig. 3, the second floor exterior wall panel 40A has a rectangular panel frame 44 and an exterior wall surface material 45 fixed to the panel frame 44 via a ventilation furring strip 44a. The panel frame 44 has a pair of vertical bars 41 on the left and right and a pair of horizontal bars 42 on the top and bottom, and is formed by welding, nailing, screwing, etc. to each other. Here, the exterior wall surface material 45 is formed of a ceramic siding material or the like having a plurality of vertical joints 45a and horizontal joints 45b on its surface. A total of four bolt holes 46 are opened near the top of the two upper corners and the two lower corners of the panel frame 44, and fixing bolts 47, 48 are screwed into each bolt hole 46. In addition, in Figure 3, two bolt holes 46 and fixing bolts 49 are shown by dashed lines at the two lower corners, but in the first floor exterior wall panel 40B, for example, fixing bolts 47, 49 are screwed into a total of four bolt holes 46 at the two upper corners and two lower corners of the panel frame 44.

[0009] As shown in Fig. 4, the second floor exterior wall panel 40A is fixed to the upper and lower eaves beams 10B and the girths 10A by engaging the lower fixing bolt 48 with the guide engagement groove 23 of the exterior wall panel mounting bracket 20A fixed to the lower girth 10A, aligning the upper bolt hole 46 with the bolt hole 27 of the exterior wall panel mounting bracket 20B fixed to the upper eaves beam 10B, and bolting via the fixing bolt 47. At this time, as shown in Fig. 4, the exterior wall panel 40 is attached in such a manner that it overhangs the front of the lower girth 10A, and the girth 10A is completely hidden by the exterior wall panel 40. In addition, below the second floor exterior wall panel 40A, the upper part of the first floor exterior wall panel 40B is bolted to the exterior wall panel mounting bracket 20B of the girth 10A with the fixing bolt 47, and the lower part of the first floor exterior wall panel 40B is bolted to the exterior wall panel mounting bracket attached to the base (not shown) with the fixing bolt.

[0010] In an existing building 100 having exterior wall panels 40B, 40A shown in Fig. 3 on the first and second floors, for example, when removing the exterior wall panel 40B on the first floor to expose the inter-floor girth 10A between the first and second floors and constructing the extension while connecting the ceiling beam of the extension (not shown) to the girth 10A, as is clear from Fig. 3, the lower part of the exterior wall panel 40A on the second floor extends to the front of the girth 10A, so the girth 10A cannot be exposed by simply removing the exterior wall panel 40B on the first floor, and the extension cannot be constructed on the first floor unless the exterior wall panel 40A on the second floor is removed. If the existing building 100 is a two-story building as in the illustrated example, it will also be necessary to remove the eaves (not shown) in order to remove the exterior wall panel 40A on the second floor, and the number of exterior wall panels and components to be removed will be even greater. In the illustrated example, the second floor exterior wall panel 40A is shown extending to the front of the girth 10A below, with the second floor exterior wall panel 40A extending to the bottom end of the girth 10A; however, "extending to the front of the girth 10A" can include various other forms, such as extending to the middle of the front of the girth 10A (thus exposing the bottom of the girth 10A) or the exterior wall panel 40A extending further downward beyond the bottom end of the girth 10A.

[0011] For the above reasons, when constructing an extension below an existing building in which exterior wall panels protrude in front of the girths below them (for example, on the first floor), there is a need for a method of expanding a building that is easy to work on and that can reduce as much as possible the number of exterior wall panels and components that need to be removed.

[0012] Here, Patent Document 1 proposes a building in which an extension (here, an extension part) is attached to an existing building (here, an existing part). Specifically, this is a building in which a second building is added to the side of an existing first building in a structurally independent manner, and the second building has a rigid-frame building unit made up of columns and girders, and is equipped with a restricting member that transmits force from the first building side to the second building side when the first building sways horizontally, thereby restricting horizontal sway of the first building relative to the second building, and one end of the restricting member is fixed to the unit frame of the second building, and the other end is provided so as to extend toward the first building. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] JP 2012-237130 A Summary of the Invention [Problem to be solved by the invention]

[0014] Although the building described in Patent Document 1 is a building in which an extension has been attached to an existing building, as described above, it does not disclose a method of adding an extension to an existing building in which the second-floor exterior wall panels protrude in front of the girths below them. Therefore, when constructing an extension below the girths of such an existing building, it does not propose a building extension method that is easy to work on and that can reduce as much as possible the number of exterior wall panels and components that need to be removed.

[0015] The present invention has been made in consideration of the above-mentioned problems, and has as its object to provide a method for expanding a building with excellent workability, which can reduce as much as possible the number of exterior wall panels and components to be removed when constructing an extension below a girth in an existing building in which the exterior wall panels protrude in front of the girth below them. [Means for solving the problem]

[0016] In order to achieve the above object, one aspect of the building extension method according to the present invention includes: A method for expanding a building by removing a part of an exterior wall of an existing multi-story building, comprising the steps of: The existing building has exterior wall panels on the upper and lower floors, and the exterior wall panel on the upper floor protrudes in front of the girder between the upper and lower floors, When extending the existing building to the outdoor side of the lower floor, a process A is performed in which the exterior wall panel of the upper floor is cut at least at a mid-way level of the girth to expose a part of the girth and reinforce the cut portion; The method is characterized by having a step B of connecting the ceiling beams of the extension to the exposed girder to construct the extension.

[0017] According to this aspect, when an exterior wall panel of an upper floor is extended to the outdoor side of a lower floor of an existing building where the exterior wall panel of the upper floor protrudes in front of the girth between the upper floor and the lower floor, the exterior wall panel of the upper floor is cut at least at the mid-height level of the girth to expose a part of the girth, and the cut part is reinforced, and then the ceiling beam of the extension part is connected to the exposed girth to construct the extension part, so that the exterior wall panel to be removed is limited to the exterior wall panel of the lower floor (for example, the first floor), and the number of exterior wall panels to be removed can be reduced as much as possible, resulting in a building extension method with excellent workability. In this aspect, the exterior wall panel of the upper floor is cut at least at the mid-height level of the girth, and the cut part of the exterior wall panel is reinforced, so that the cut part of the exterior wall panel can be prevented from becoming a structurally weak part of the exterior wall panel even while cutting the exterior wall panel of the upper floor at its mid-height position. Here, "at least halfway up the height of the girth" means not only any level halfway up the height of the girth, such as the lower end level of the upper flange of the girth formed by H-shaped steel or a height level slightly lower than the upper flange, but also a height level higher than the upper end of the girth (for example, the upper end of the upper flange of the H-shaped steel).

[0018] In another aspect of the method for expanding a building according to the present invention, The exterior wall panel includes at least an exterior wall surface material, a panel frame, and a heat insulating material, In the step A, reinforcing horizontal bars are screwed to the lower sides of the left and right vertical bars that constitute the cut panel frame.

[0019] According to this embodiment, the reinforcing horizontal bars are screwed together at the cut points of the left and right vertical bars of the panel frame that constitutes the exterior wall panel, thereby effectively reinforcing the cut points of the main structure of the exterior wall panel. Here, "comprising at least an exterior wall surface material, a panel frame, and a heat insulating material" means that the exterior wall panel is provided with, in addition to the exterior wall surface material, the panel frame, and the heat insulating material, a ventilated furring strip made of, for example, polystyrene between the exterior wall surface material and the panel frame. The exterior wall surface material is formed, for example, from a siding material, and examples of this siding material include ceramic siding, metal siding made of aluminum or steel plate, wood siding made of processed natural wood, and resin siding made of polyvinyl chloride resin.

[0020] For example, by fitting reinforcing horizontal bars, also made of light steel channel steel, into the left and right vertical bars of a panel frame made of light steel channel steel from below and connecting them with screws, no welding is required, making it possible to carry out construction without risk of fire while residents continue to live in the existing building. Here, the screws in screw connections include not only literal screws, but also screws, nails, bolts, etc.

[0021] In another aspect of the method for expanding a building according to the present invention, The exterior wall panel has a width that is an integer multiple of the module width, The ceiling beam is connected to the girth at a position set back a predetermined width from a position that is an integer multiple of the module width.

[0022] According to this aspect, by connecting the ceiling beam to the exposed girth at a position that is set back a predetermined width from a position that is an integer multiple of the module width of the exterior wall panel, it is sufficient to remove only the exterior wall panel in the area where the extension is to be constructed on the first floor, for example, and it is unnecessary to remove the exterior wall panels to the side of it.

[0023] The module width (1P) is a width that can be set arbitrarily between 800mm and 1100mm according to the module design specifications, for example, 1P can be set to 910mm. Normally, pillars and partitions are erected at the module core position, and exterior wall panels with widths (1P width, 2P width, etc.) that are integral multiples (1x, 2x, etc.) of the module width are attached to them. When ceiling beams are installed at positions that are integral multiples of the module width (in other words, the module core position, which includes 0x), the exterior wall panels adjacent to the construction area of ​​the extension obstruct the installation of the ceiling beams, making it necessary to remove these adjacent exterior wall panels, which increases the number of exterior wall panels to be removed.

[0024] Therefore, in this embodiment, by attaching the ceiling beams of the extension to a position (a position set back to the inside of the construction area of ​​the extension) set back by a predetermined width from the position of an integral multiple of the module width of the exposed girth (position of 0, 1, 2, etc. at the module core position), it is possible to eliminate the need to remove the exterior wall panels adjacent to the construction area of ​​the extension, and together with the above-mentioned cutting of the exterior wall panels of the upper floor at their midpoints, it is possible to further reduce the number of exterior wall panels to be removed. For example, when 1P is set to 910 mm and the width of the exterior wall panel is set to 1P width or 2P width, the predetermined setback width can be set to 1 / 4 of 1P, or 227.5 mm.

[0025] In another aspect of the method for expanding a building according to the present invention, When one side of the extension is located near a protruding corner of an existing building, the ceiling beam is connected to a position inside the end of the protruding corner with the girth, while leaving the corner cover at the protruding corner in place.

[0026] According to this aspect, when one side of the extension is located near a protruding corner of an existing building, the extension can be constructed near the protruding corner of the existing building without removing the corner cover by attaching a ceiling beam to a position set back inward from the module core of the end of the protruding corner in the girth, while leaving the corner cover at the protruding corner. For example, there is a form in which a ceiling beam at the end of the extension is attached to a position set back inward by a predetermined width, such as the above-mentioned P / 4 width, from the column center (module core) of the column at the protruding corner.

[0027] Another aspect of the building extension method according to the present invention is to In the step B, a connecting metal fitting is bolted to the exposed girth, and the ceiling beam is bolted to the connecting metal fitting.

[0028] According to this aspect, by bolting the connecting metal fittings to the exposed girths and bolting the ceiling beams to the connecting metal fittings, it becomes possible to efficiently attach the ceiling beams of the extension to the girths of the existing building without the need for welding. For example, by applying a one-sided bolt that can be bolted only from the outside, it becomes possible to construct the extension while residents are still living in the existing building, eliminating the risk of fire without the need for welding.

[0029] In another aspect of the method for expanding a building according to the present invention, The step A is characterized in that a drainage steel plate for draining rainwater from the inside of the exterior wall panel to the outside is installed at the cut portion.

[0030] According to this aspect, by installing a drainage steel plate that leads from the ventilation layer to the outside at the cut portion of the exterior wall panel, a drainage path can be formed from the exterior wall panel of the upper floor of the existing building to the roof of the extension constructed below. Here, the roof of the extension is constructed as, for example, a flat roof or a balcony. Effect of the Invention

[0031] As can be understood from the above explanation, according to the building extension method of the present invention, in an existing building in which exterior wall panels protrude in front of the furring strips below them, when constructing an extension section below the furring strips, the number of exterior wall panels to be removed can be reduced as much as possible, making it possible to construct the extension section with excellent workability. [Brief description of the drawings]

[0032] [Figure 1] This is an external perspective view showing an example of an extension constructed on an existing building. [Diagram 2] This is a front view showing two upper and lower beams (eaves beam and girder) in an existing building, and an example of exterior wall panel mounting brackets attached to each beam. [Diagram 3] FIG. 2 is a perspective view of an example of an exterior wall panel, viewed obliquely from the rear. [Figure 4] This is a front view showing the state in which the exterior wall panel shown in Figure 3 is attached to the eaves beam and girder shown in Figure 2 as the exterior wall panel for the second floor, and a separate exterior wall panel is further attached to the girder as the exterior wall panel for the first floor. [Diagram 5] FIG. 2 is a process diagram illustrating an example of a method for expanding a building according to an embodiment. [Figure 6] Continuing from FIG. 5, this is a process diagram illustrating an example of a building extension method according to the embodiment. [Figure 7] Following FIG. 6, this is a process diagram illustrating an example of a building extension method according to the embodiment. [Figure 8] 7, a process diagram illustrating an example of a building extension method according to the embodiment will be described. [Figure 9] 9 is a view taken in the direction of an arrow IX in FIG. 8. [Figure 10] Following FIG. 8, this is a process diagram illustrating an example of a building extension method according to the embodiment. [Figure 11] An enlarged view of the connecting hardware attached to the beam. [Figure 12] 10, a process diagram illustrating an example of a method for extending a building according to an embodiment of the present invention will be described below. [Figure 13] 12, following FIG. 10, is a process diagram illustrating an example of a method for extending a building according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Hereinafter, an example of a method for expanding a building according to an embodiment will be described with reference to the accompanying drawings. In this specification and the drawings, substantially identical components may be designated by the same reference numerals to avoid redundant description.

[0034] [Method of expanding a building according to the embodiment] An example of a building extension method according to the embodiment will be described with reference to Fig. 5 to Fig. 13. Here, Fig. 5 to Fig. 8, Fig. 10, Fig. 12, and Fig. 13 are process diagrams for explaining an example of a building extension method according to the embodiment, in that order.

[0035] 1 to 4, an example of a method of constructing an extension 200 by removing a portion of the exterior walls 110 on the first floor (an example of a lower floor) and the second floor (an example of an upper floor) of an existing two-story light-gauge steel-framed building 100 will be described. That is, in the existing building 100, the exterior wall panels 40B, 40A on the first and second floors are attached in the form shown in FIG.

[0036] In the example shown in Fig. 1, an extension 200 is constructed near one corner (a protruding corner) of the first floor of an existing building 100. As shown in Fig. 5, at one corner of the existing building 100, a corner cover 50 having an L-shaped cross section perpendicular to the longitudinal direction is attached to the outdoor side of a column 80A (see Fig. 12) via a thermal insulation material.

[0037] Returning to Fig. 5, the vertical joint 32 between the corner cover 50 and the exterior wall panels 40A, 40B on its side coincides with the module core L1, and the exterior wall panels 40A, 40B with a width of 1P (here, P is 910 mm) are arranged up, down, left and right from the module core L1 to the side (left side of Fig. 5). In other words, the exterior wall panel 40 has a width that is an integer multiple of the module width. Therefore, the module core L1, the vertical joint 32 on the 1P side (left side of Fig. 5) from the module core L1, and the separate vertical joint 32 on the 1P side (left side of Fig. 5) are also located at integer multiples from the module core L1 at the corner end (the module core L1 is also located at 0 times, which is an integer, from the module core L1).

[0038] The lower end of the second floor exterior wall panel 40A extends to the lower end of the girth 10A in front of the girth 10A, and a horizontal joint 34 is formed below the girth 10A between the second floor exterior wall panel 40A and the first floor exterior wall panel 40B.

[0039] The extension section 200 is to be constructed within a range of width 2P from the corner cover 50 shown in Fig. 5. The construction range of the extension section 200 may be set to a range of width 3P or more from the corner cover 50. In the extension method of the illustrated example, first, as shown in Fig. 6, the exterior wall panel 40B of the first floor within the range of width 2P is removed, and the exterior wall panel 40A of the second floor is cut at the mid-height level of the girths 10A of the exterior wall panel 40A (the lower end of the upper flange of the H-shaped steel) to expose a part of the girths 10A.

[0040] As already explained with reference to Fig. 3, the exterior wall panel 40A is formed by attaching the exterior wall surface material 45 via the ventilation furring strips 44a to the outside of the panel frame 44. More specifically, as shown in Fig. 12 etc., an exterior insulating material 58 such as a glass wool board is attached between the ventilation furring strips 44a and the panel frame 44, and the inside of the panel frame 44 is filled with insulating material 56 such as glass wool.

[0041] Returning to Figure 6, of the exterior wall panel 40A on the second floor, the vertical bar 41 that forms the panel frame 44 is cut below the engagement point with the exterior wall panel mounting bracket 20A above the girth 10A (the lower end of the upper flange of the girth 10A), and the exterior wall surface material 45 is cut above the cut lower end of the vertical bar 41 so that the lower part of the vertical bar 41 is exposed, thereby forming a cut point 40a of the exterior wall panel 40A above the girth 10A.

[0042] In addition, in conventional extension methods, when constructing an extension at one corner, it is common to also remove the corner cover and set the module core L1 as the beam core of the ceiling beam of the extension; however, in the extension method of the illustrated example, the extension can be constructed without removing the corner cover 50, so the corner cover 50 is left in place.

[0043] At the cut location 40a, the lower horizontal bars 42 (see FIG. 3) have been removed from the panel frame 44, reducing the rigidity of the panel frame 44. Therefore, first, as shown in FIG. 7, reinforcing horizontal bars 60 are inserted into the left and right vertical bars 41, and then fixed to the vertical bars 41 with drill screws 60b as shown in FIG. 9 to reinforce the panel frame 44.

[0044] The reinforcing horizontal bar 60 is formed from a channel steel or the like, similar to the vertical bars 41 of the panel frame 44, and as shown in Figure 9, is provided with an attachment piece 60a on the back surface of the web of the channel steel. The attachment piece 60a is abutted against the inner surface of the web of the vertical bar 41 with the opening of the channel steel facing downward, and is fixed in place via a drill screw 60b.

[0045] After reinforcing the lower part of the panel frame 44 with the reinforcing horizontal bars 60, the base horizontal bars 61, 62 are attached with screws 63 with gaps between them to the exposed surface of the vertical bars 41 of the panel frame 44, as shown in Fig. 8. Then, as shown in Fig. 9, a drainage steel plate 65 having a generally Z-shape in side view is attached from the back surface of the base horizontal bar 61 below the ventilation furring strip 44a at the cut portion 40a of the exterior wall panel 40A to the exposed surface of the lower base horizontal bar 62.

[0046] This drainage steel plate 65 makes it possible for rainwater flowing down the ventilation layer 44b formed by the ventilation furring strips 44a of the exterior wall panel 40A in the X1 direction to be drained through a drainage path in the X2 direction along the outer surface of the drainage steel plate 65. The roof of the extension 200 shown in Fig. 1 is disposed below the drainage steel plate 65, and this roof is constructed as, for example, a flat roof or a balcony as in the illustrated example.

[0047] After the drainage steel plate 65 is attached, in order to hide the upper base horizontal rail 61, the piece-shaped exterior wall surface material 45' is attached in the Y1 direction as shown in Fig. 9 (this is process A). Fig. 9 also shows the interior wall panel frame 55 on the indoor side of the exterior wall panel 40A, the filled insulation material 56, the gypsum board 57 fixed to the indoor side of the panel frame 55, the second floor floor material 59, etc.

[0048] Next, as shown in FIG. 10, a connecting hardware 70 for attaching a ceiling beam 90 (see FIGS. 12 and 13) of the extension is fixed to the side surface of the web 13 of the girder 10A with a one-side bolt 75.

[0049] 11, the connecting hardware 70 is a hat-shaped steel hardware in a plan view, having a U-shaped piece 71 and left and right side pieces 72 extending laterally from both ends of the U-shaped piece 71. A bolt hole (not shown) opened in the web 13 and a bolt hole (not shown) opened in the side piece 72 are aligned, and a one-sided bolt 75 is screwed into both bolt holes.

[0050] A plurality of bolt holes 73 (six in the illustrated example) are formed in the U-shaped piece 71. As shown in Fig. 12, the ceiling beam 90 of the extension is formed of an H-shaped steel, and an end plate 91 is attached to the end of the H-shaped steel. A fastening nut 76 is fixed in advance to the back surface of each bolt hole 73 of the U-shaped piece 71, and the ceiling beam 90 of the extension is connected to the girth 10A via the connecting metal fitting 70 by abutting the end plate 91 against the U-shaped piece 71, aligning a bolt hole (not shown) formed in the end plate 91 with the bolt hole 73 of the U-shaped piece 71, and screwing in a bolt 77.

[0051] In the extension method shown in the figure, welding is not required to connect components together, as the connection hardware 70 is connected to the girder 10A with a one-sided bolt 75, the ceiling beam 90 is connected to the connection hardware 70 with a bolt, and further, as described above, the reinforcing cross beam 60 is fixed to the vertical beam 41 with a drill screw 60b. This makes it possible to construct the extension 200 without risk of fire while residents continue to live in the existing building 100.

[0052] Returning to Fig. 10, the attachment position of one connecting hardware 70 (right side in Fig. 10) for girth 10A is a position (position L3) set back P / 4 (1P is the module width, here 910mm) from the module core L1 on the side of the corner cover 50, and the attachment position of the other connecting hardware 70 (left side in Fig. 10) for girth 10A is a position (position L6) set back P / 4 from the module core L4, which is twice the module width (2P) from the module core L1 on the side of the corner cover 50. Fig. 12 shows the relationship between the module core L1 and the setback position L3 in a plan view, and Fig. 13 shows the relationship between the module core L4 and the setback position L6 in a plan view.

[0053] Returning to Figure 10, by setting the mounting positions of the ceiling beams 90 in the extension section at positions set back a specified width from the module cores L1 and L4, respectively, it is possible to leave the corner covers 50 in place and, further, to eliminate the need to remove the exterior wall panels 40A and 40B on the left side of the module core L4.

[0054] As already explained, in step A, the exterior wall panel 40A on the second floor is cut at the midpoint of the height of the girth 10A in the exterior wall panel 40A to expose a portion of the girth 10A, thereby making it unnecessary to remove the exterior wall panel 40A on the second floor or to remove the eaves, etc. In addition to this, by setting the mounting position of the ceiling beam 90 of the extension part to a position within the construction range of the extension part set back by a predetermined width from the module core, it is further unnecessary to remove the corner cover 50 or the exterior wall panel 40 on the side of the extension part 200. As a result, the construction range can be prevented from expanding during construction of the extension part 200, resulting in an extension method with excellent construction properties.

[0055] As shown in Figures 12 and 13, columns 80C of the extension section 200 are erected at positions L3, L6 set back from the module cores L1, L4, and ceiling beams 90 are bolted to the connecting hardware 70 attached to the girder 10A to span between the connecting hardware 70 and columns 80C.

[0056] As shown in Figure 12, by setting the extension part 200 back P / 4 from the corner cover 50, the end of the extension part 200 on the corner cover side forms an inside corner, but a piece-shaped exterior wall material 45" is attached to the side of the corner cover 50, and the exterior wall panel 40C of the extension part is attached so that one end of it abuts against the surface of the piece-shaped exterior wall material 45". At this time, a drainage steel plate 66 that is L-shaped in plan view and a water-stopping material 67 preset thereto are interposed at the interface between the exterior wall panel 40C of the extension part and the piece-shaped exterior wall material 45", forming a water-stopping structure at the inside corner.

[0057] 13, the end of the extension 200 opposite the corner cover also forms an inside corner, but the exterior wall panel 40C of the extension is attached so that one end of it abuts against the surface of the exterior wall panel 40B of the existing building 100. At this time, a flat drainage steel plate 68 and a water-stopping material 69 preset therein are interposed at the interface between the exterior wall panel 40C of the extension and the exterior wall panel 40B of the existing building 100, thereby forming a water-stopping structure at the inside corner.

[0058] 12 shows that there is a pillar 80B (partition stud) at a position 1P from the module core L1, and that an interior wall panel frame 55 and gypsum board 57 are attached to the indoor side of each of the pillars 80A, 80B. Also, as shown in Figs. 12 and 13, an interior wall panel frame (not shown) is attached below the ceiling beam 90, and gypsum board 57 is attached to this panel frame. Although not shown, the exterior wall panels of the extension part that spans each of the pillars 80C shown in Figs. 12 and 13 are further attached, and the roof of the extension part 200 (flat roof, balcony, etc.) is constructed, thereby constructing the extension part 200 (the above is process B).

[0059] In addition, the present invention is not limited to the configuration shown here, and may be implemented in other embodiments in which other components are combined with the configurations and the like of the above-mentioned embodiment. In this regard, the present invention may be modified within the scope of the gist of the present invention, and may be appropriately determined according to the application form. [Explanation of symbols]

[0060] 10A: Beam (body) 10B: Beam (eave girder) 11: Top flange 12: Lower flange 13: Web 20A, 20B: Exterior wall panel mounting brackets 21,24: Fixed piece 22,25: Contact piece 23, 26: Guide engagement groove 27: Bolt hole 28: Bolt 32: Vertical joint 34: Horizontal joint 40: Exterior wall panel 40A: Second floor exterior wall panel 40B: First floor exterior wall panel 40C: Exterior wall panel of extension 40a: Cutting point 41: Vertical bar 42: Horizontal bar 44: Panel frame 44a: Ventilated furring strip 44b: Ventilation layer 45: Exterior wall material 45': Piece-shaped exterior wall material 45": Piece-shaped exterior wall material 45a: Vertical pattern joint 45b: Horizontal joint 46: Bolt hole 47, 48, 49: Fixing bolts 50: Corner cover 55: Panel frame 56: Insulation 57: Plasterboard 58:Exterior insulation 59:Flooring 60: Reinforcing crosspiece 60a: Mounting piece 60b: Screw 61,62: Base horizontal bars 63: Bis 65: Drainage steel plate 66,68: Drainage steel plate 67, 69: Water-stopping material 70: Connection hardware 71: U-shaped piece 72: Side piece 73: Bolt hole 75: Bolt (one-sided bolt) 76: Fastening nut 77: Bolt 80A, 80B, 80C: Pillar 90: Ceiling beam 91: End plate 100: Existing building 110: Exterior wall 200: Extension

Claims

1. A method for expanding a building by removing a part of an exterior wall of an existing multi-story building, comprising the steps of: The existing building has exterior wall panels on the upper and lower floors, and the exterior wall panel on the upper floor protrudes in front of the girder between the upper and lower floors, When extending the existing building to the outdoor side of the lower floor, a process A is performed in which the exterior wall panel of the upper floor is cut at least at a mid-way level of the height of the girth to expose a part of the girth and reinforce the cut portion; A step B of connecting a ceiling beam of an extension part to the exposed girth to construct the extension part, The exterior wall panel includes at least an exterior wall surface material, a panel frame, and a heat insulating material, A method for extending a building, characterized in that in step A, reinforcing horizontal bars are screwed below the left and right vertical bars that make up the cut panel frame.

2. A method for expanding a building by removing a part of an exterior wall of an existing multi-story building, comprising the steps of: The existing building has exterior wall panels on the upper and lower floors, and the exterior wall panel on the upper floor protrudes in front of the girder between the upper and lower floors, When extending the existing building to the outdoor side of the lower floor, a process A is performed in which the exterior wall panel of the upper floor is cut at least at a mid-way level of the height of the girth to expose a part of the girth and reinforce the cut portion; A step B of connecting a ceiling beam of an extension part to the exposed girth to construct the extension part, The exterior wall panel has a width that is an integer multiple of the module width, A method for extending a building, comprising the steps of: connecting the ceiling beam to the girth at a position set back a predetermined width from a position that is an integer multiple of the module width.

3. 3. The method for extending a building as described in claim 2, characterized in that, when one side of the extension is located near a protruding corner of an existing building, the ceiling beam is connected to a position inside the end of the protruding corner with the girth, while leaving a corner cover at the protruding corner.

4. A method for expanding a building by removing a part of an exterior wall of an existing multi-story building, comprising the steps of: The existing building has exterior wall panels on the upper and lower floors, and the exterior wall panel on the upper floor protrudes in front of the girder between the upper and lower floors, When extending the existing building to the outdoor side of the lower floor, a process A is performed in which the exterior wall panel of the upper floor is cut at least at a mid-way level of the height of the girth to expose a part of the girth and reinforce the cut portion; A step B of connecting a ceiling beam of an extension part to the exposed girth to construct the extension part, A method for expanding a building, characterized in that in step B, connecting metal fittings are bolted to the exposed girder beams, and the ceiling beams are bolted to the connecting metal fittings.

5. A method for expanding a building by removing a part of an exterior wall of an existing multi-story building, comprising the steps of: The existing building has exterior wall panels on the upper and lower floors, and the exterior wall panel on the upper floor protrudes in front of the girder between the upper and lower floors, When extending the existing building to the outdoor side of the lower floor, a process A is performed in which the exterior wall panel of the upper floor is cut at least at a mid-way level of the height of the girth to expose a part of the girth and reinforce the cut portion; A step B of connecting a ceiling beam of an extension part to the exposed girth to construct the extension part, The method for expanding a building, wherein in the step A, a drainage steel plate for draining rainwater from the inside of the exterior wall panel to the outside is installed at the cut location.

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