Architectural renovation methods

Abstract

This invention provides a building renovation method that reduces the need to revise the ventilation path plan of a 24-hour ventilation system when replacing existing door and window fixtures with sealed types. [Solution] The first ventilated door device (10A) that forms an opening (5) in the partition wall (W1) separating the corridor (S1) and the bedroom (S2) is removed and replaced with a second sealed door device (10B). In addition, a first opening (26) is formed in the first ceiling material (20) that forms the ceiling (CL) of the corridor (S1), and a second opening (36) is formed in the second ceiling material (30) that forms the ceiling (CL) of the bedroom (S2). A ventilation duct (60) connecting the first opening (26) and the second opening (36) is installed in the space above the ceiling (AS). The ventilation duct (60) is a sound-absorbing duct (61) that includes sound-absorbing material (62).

Description

[Technical Field]

[0001] This invention relates to a method for renovating buildings. [Background technology]

[0002] Buildings are equipped with a continuous ventilation system, also known as a 24-hour ventilation system, which constantly circulates air. Depending on the ventilation plan of the 24-hour ventilation system, it may be necessary to circulate air between two adjacent spaces through a partition wall with an opening. In this case, it is common to use a door or window device that opens and closes the opening in the partition wall, and that has an undercut, or ventilation opening, on the underside of the door or window to allow air to circulate, so that the underside of the door or window becomes a ventilation path even when the door or window is closed.

[0003] An example of such a building fixture is disclosed in Patent Document 1. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-139843 [Overview of the project] [Problems that the invention aims to solve]

[0005] As disclosed in Patent Document 1, if there is an undercut on the lower side of a door or window that forms a door or window device, sound leakage occurs between the two usable spaces through the undercut. Therefore, it is conceivable to carry out a renovation to replace a ventilated door or window device with an airtight door or window device. An airtight door or window device is configured to seal the opening in the partition wall when it is closed.

[0006] However, such renovations can disrupt airflow between the two spaces. Therefore, it may be necessary to revise the ventilation route plan for the 24-hour ventilation system. Revising the ventilation route for a 24-hour ventilation system is time-consuming, and if the space being used is a living room, it may be necessary to implement forced ventilation by installing a ventilation system that completes both supply and exhaust air within that room alone.

[0007] The present invention has been made in view of the above, and its purpose is to provide a building renovation method that, when renovating a building to solve the problem of sound leakage by replacing the building fixtures with sealed ones, can reduce the need to revise the ventilation route plan of the 24-hour ventilation system while making use of the existing ventilation equipment. [Means for solving the problem]

[0008] To achieve the above objectives, the present invention replaces the fittings installed in the opening of the partition wall separating the first and second usable spaces with sealed fittings, and installs a ventilation duct in the ceiling space that allows air to circulate between the first and second usable spaces, with a configuration that includes sound-absorbing material.

[0009] Specifically, the first invention relates to a building renovation method comprising a partition wall separating a first and second adjacent usable space in an indoor space, a first joinery device capable of opening and closing an opening provided in the partition wall, a first ceiling material forming the ceiling of the first usable space, and a second ceiling material forming the ceiling of the second usable space, wherein the space above the ceiling extends above the first ceiling material and above the second ceiling material, and the first joinery device is configured to form a gap that allows air to circulate between the first and second usable spaces. The building renovation method includes a first step of removing the first joinery device and replacing the first joinery device with a second joinery device configured to seal the opening in a closed state; a second step of forming a first opening in the first ceiling material and a second opening in the second ceiling material; and a third step of installing a ventilation duct in the ceiling space that connects the first opening and the second opening and allows air to circulate between the first usable space and the second usable space, using a sound-absorbing duct that includes sound-absorbing material.

[0010] According to the first invention, the fitting device installed in the opening of the partition wall separating the first and second usable spaces is replaced from a first fitting device configured to create a gap that allows air to circulate between the first and second usable spaces to a second fitting device configured to seal the opening when it is closed. This suppresses sound leakage from one of the first and second usable spaces to the other through the opening. After forming a first opening in the first ceiling material that forms the ceiling of the first usable space and a second opening in the second ceiling material that forms the ceiling of the second usable space, a ventilation duct connecting the first and second openings is installed in the space above the ceiling using a sound-absorbing duct. Air can circulate through the ventilation duct. Furthermore, since the sound-absorbing duct is made up of sound-absorbing material, it can attenuate sound propagating inside the ventilation duct, thereby suppressing sound leakage from one of the first and second usable spaces to the other through the ventilation duct. Therefore, it is possible to improve sound insulation between the first and second usage spaces while securing a ventilation path between them. This reduces the need to revise the ventilation path plan for the 24-hour ventilation system while utilizing existing ventilation equipment.

[0011] The second invention is a building renovation method according to the first invention, wherein in the third step, a flexible sound-absorbing duct is used as the sound-absorbing duct.

[0012] According to the second invention, since the sound-absorbing duct used in the ventilation duct is flexible, it is easy to avoid interference with structural members such as beams in the ceiling space by bending the sound-absorbing duct. Therefore, the workability when installing the ventilation duct in the ceiling space is good.

[0013] The third invention relates to the building renovation method of the first or second invention, wherein the effective opening area of ​​the ventilation duct is 100 cm². 2The above describes the building renovation method. The second building fixture has sound insulation performance that reduces the sound pressure level by 20 dB or more at a frequency of 500 Hz. After the renovation, a sound insulation effect is obtained that reduces the sound pressure level between the first and second usable spaces by 20 dB or more at a frequency of 500 Hz.

[0014] According to the third invention, the effective opening area of ​​the ventilation duct is 100 cm². 2 As described above, the necessary effective opening area for the ventilation path of the 24-hour ventilation system can be secured between the first and second usage spaces. Therefore, the ventilation path using the ventilation duct can be suitably used as the ventilation path for the 24-hour ventilation system. Furthermore, after the renovation, a sound insulation effect equivalent to the sound insulation performance of the second door and window device can be obtained between the first and second usage spaces, thus achieving both ventilation and sound insulation between the first and second usage spaces. This design achieves both sound insulation and ventilation between two adjacent spaces separated by a partition wall within an indoor environment.

[0015] The fourth invention is a building renovation method according to any one of the first to third inventions, wherein in the second step, the first opening is formed to have an inner diameter that is larger than the outer diameter of one end of the sound-absorbing duct and smaller than the outer diameter of the sound-absorbing duct in the middle in the longitudinal direction. In the third step, the portion including one end of the sound-absorbing duct is brought from the ceiling space through the first opening into the first usable space. Leave it in the extended state. After attaching a component of the first ventilation grille to one end of the sound-absorbing duct, from the first opening of the sound-absorbing duct It's out The portion is placed in the space above the ceiling, and the first ventilation grille is provided on the lower surface of the first ceiling material so as to cover the gap between one end of the sound-absorbing duct and the inner periphery of the first opening.

[0016] According to the fourth invention, the first opening is formed with an inner diameter that is larger than the outer diameter of one end of the sound-absorbing duct and smaller than the outer diameter of the sound-absorbing duct in the middle in the longitudinal direction. Compared to the case where the first opening is formed with an inner diameter larger than the outer diameter of the sound-absorbing duct in the middle in the longitudinal direction, and compared to the case where the first opening is formed with a smaller diameter and an inner diameter smaller than the outer diameter of one end of the sound-absorbing duct, the load on the sound-absorbing duct when inserting it into the first opening can be reduced. This is advantageous for making the first ventilation grille relatively small and improving the workability when installing the ventilation duct in the space above the ceiling. Furthermore, since the first ventilation grille is provided on the underside of the first ceiling material so as to cover the gap between one end of the sound-absorbing duct and the inner periphery of the first opening, the gap is concealed by the first ventilation grille, improving the appearance of the ceiling of the first usable space.

[0017] The fifth invention is a building renovation method of the fourth invention, wherein in the second step, the second opening is formed to have an inner diameter that is larger than the outer diameter of the other end of the sound-absorbing duct and smaller than the outer diameter of the middle of the sound-absorbing duct in the longitudinal direction. In the third step, the portion of the sound-absorbing duct including the other end is brought from the ceiling space through the second opening into the second usable space. Leave it in the extended state. After attaching the components of the second ventilation grille to the other end of the sound-absorbing duct, from the second opening of the sound-absorbing duct It's out The portion is placed in the space above the ceiling, and the second ventilation grille is provided on the lower surface of the second ceiling material so as to cover the gap between the other end of the sound-absorbing duct and the inner periphery of the second opening.

[0018] According to the fifth invention, since the second opening is formed to have an inner diameter that is larger than the outer diameter of the other end of the sound-absorbing duct and smaller than the outer diameter in the middle of the sound-absorbing duct in the length direction, compared with the case where the second opening is formed to have an inner diameter larger than the outer diameter in the middle of the sound-absorbing duct in the length direction, while forming the second opening to have a small diameter, compared with the case where the second opening is formed to have an inner diameter smaller than the outer diameter of the other end of the sound-absorbing duct, the load applied to the sound-absorbing duct when inserting the sound-absorbing duct into the second opening can be reduced. This is advantageous for making the second ventilation grille relatively small and improving the workability when providing the ventilation duct in the ceiling space. And since the second ventilation grille is provided on the lower surface of the second ceiling material so as to cover the gap between the other end of the sound-absorbing duct and the inner peripheral edge of the second opening, the gap is concealed by the second ventilation grille, and the appearance of the ceiling of the second use space can be improved.

[0019] The sixth invention is a building renovation method according to the fifth invention, wherein in the third step, the sound-absorbing duct is placed into the ceiling space through the first opening, and while maintaining the state in which one end of the sound-absorbing duct is brought out from the ceiling space through the first opening into the first usable space, the other end of the sound-absorbing duct is pulled out from the second opening into the second usable space.

[0020] The 7 invention is a building renovation method including a fourth step of attaching a first cover member to the inner peripheral edge of the first opening of the first ceiling material in the renovation method of any one of the first to 6 inventions. In the third step, the sound-absorbing duct is inserted from the first use space into the ceiling space through the first opening in a state where the first cover member is attached to the inner peripheral edge.

[0021] The 7 invention, when inserting the sound-absorbing duct into the first opening, since the first cover member is attached to the inner peripheral edge of the first opening of the first ceiling material and is located between the inner peripheral edge of the first opening and the sound-absorbing duct, it is possible to suppress the sound-absorbing duct from being damaged by directly hitting and rubbing against the inner peripheral edge of the first opening, or to prevent damage to the inner peripheral edge of the first opening and the falling of fragments, etc.

[0022] The 8 invention is the 7In the building renovation method of the invention, the fourth step is to attach the first cover member in a ring shape to the inner periphery of the first opening of the first ceiling material such that its inner diameter is larger than the outer diameter of one end of the sound-absorbing duct.

[0023] The 8 According to this invention, since the inner diameter of the first cover member attached to the inner periphery of the first opening of the first ceiling material is larger than the outer diameter of one end of the sound-absorbing duct, it is relatively easy to insert the sound-absorbing duct from the first usable space into the ceiling space through the first opening, and the load on the sound-absorbing duct when inserting it into the first opening can be reduced.

[0024] The 9 The invention is the first 7 In the building renovation method of the invention, the fourth step is to attach a second cover member to the inner periphery of the second opening of the second ceiling material. In the third step, the sound-absorbing duct is inserted from the ceiling space to the second usable space through the second opening with the second cover member attached to its inner periphery.

[0025] The 9 According to this invention, when inserting the sound-absorbing duct through the second opening, the second cover member is attached to the inner periphery of the second opening of the second ceiling material and positioned between the inner periphery of the second opening and the sound-absorbing duct. This prevents the sound-absorbing duct from being damaged by directly contacting and rubbing against the inner periphery of the second opening, and also prevents damage to the inner periphery of the second opening and the falling of fragments.

[0026] The 10 The invention is the first 9 In the building renovation method of the invention, the fourth step is to attach the first cover member in an annular manner to the inner periphery of the first opening of the first ceiling material such that its inner diameter is larger than the outer diameter of one end of the sound-absorbing duct, and to attach the second cover member in an annular manner to the inner periphery of the second opening of the second ceiling material such that its inner diameter is larger than the outer diameter of the other end of the sound-absorbing duct.

[0027] The 10 According to this invention, since the inner diameter of the first cover member attached to the inner periphery of the first opening of the first ceiling material is larger than the outer diameter of one end of the sound-absorbing duct, it is relatively easy to insert the sound-absorbing duct from the first usable space to the ceiling space through the first opening, and the load on the sound-absorbing duct when inserting it into the first opening can be reduced. Furthermore, since the inner diameter of the second cover member attached to the inner periphery of the second opening of the second ceiling material is larger than the outer diameter of the other end of the sound-absorbing duct, it is relatively easy to pull the sound-absorbing duct from the ceiling space to the second usable space through the second opening, and the load on the sound-absorbing duct when inserting it into the second opening can be reduced.

[0028] The 11 The invention is the first to the 10 In any one of the inventions, a method for renovating a building, wherein the third step involves the sound-absorbing duct forming the entire ventilation duct.

[0029] The 11 According to this invention, since the entire ventilation duct is composed of sound-absorbing ducts, a first opening is formed in the first ceiling material and a second opening in the second ceiling material, and by simply inserting the sound-absorbing duct into the space above the ceiling through the first or second opening and connecting both ends to the first and second openings, the ventilation duct can be installed in the space above the ceiling in the third step. Furthermore, the installation of such a ventilation duct can be completed in the first and second usable spaces without removing the first and second ceiling materials. [Effects of the Invention]

[0030] As described above, the present invention provides a building renovation method that reduces the need to revise the ventilation path plan of a 24-hour ventilation system while utilizing existing ventilation equipment. This is achieved by replacing the fixtures installed in the opening of the partition wall separating the first and second usable spaces from a ventilated type to a sealed type, and by installing a ventilation duct in the ceiling space with a configuration that includes sound-absorbing material to allow air to circulate between the first and second usable spaces. [Brief explanation of the drawing]

[0031] [Figure 1] This is a cross-sectional view illustrating the configuration of the indoor space, including the living room, that is the target of renovation in the building according to Embodiment 1. [Figure 2] This is a cross-sectional view illustrating the space above the ceiling of a building before renovation according to Embodiment 1. [Figure 3] This is a front view illustrating the configuration of the joinery device before renovation of a building according to Embodiment 1. [Figure 4] This is a front view illustrating an opening in a building renovation according to Embodiment 1, with the first packing attached to the door frame. [Figure 5] This is a front view illustrating the configuration of the joinery device after renovation of a building according to Embodiment 1. [Figure 6] This is a diagram illustrating the configuration of a sound-absorbing duct used in the renovation of a building according to Embodiment 1. [Figure 7] This is a plan view of a ventilation grill used in building renovation according to Embodiment 1. [Figure 8] Figure 4 is a cross-sectional view of the ventilation grille along line VIII-VIII. [Figure 9A] This figure shows a part of the building renovation work according to Embodiment 1. [Figure 9B] This figure shows a part of the building renovation work according to Embodiment 1. [Figure 9C] This figure shows a part of the building renovation work according to Embodiment 1. [Figure 9D] This figure shows a part of the building renovation work according to Embodiment 1. [Figure 9E] This figure shows a part of the building renovation work according to Embodiment 1. [Figure 9F] This figure shows a part of the building renovation work according to Embodiment 1. [Figure 9G] This figure shows a part of the building renovation work according to Embodiment 1. [Figure 10] This is a cross-sectional view illustrating a ventilation structure that utilizes the space above the ceiling after renovation of a building according to Embodiment 1. [Figure 11] This is a cross-sectional view illustrating the configuration of the indoor space, including the bedroom, after renovation of the building according to Embodiment 1. [Figure 12] This is a cross-sectional view illustrating a ventilation structure that utilizes the space above the ceiling after renovation of a building according to Embodiment 2. [Figure 13A] This is a top view showing the installation state of the ventilation duct according to Embodiment 2. [Figure 13B] This is a top view showing another installation configuration of the ventilation duct according to Embodiment 2. [Figure 13C] This is a top view showing another installation configuration of the ventilation duct according to Embodiment 2. [Figure 13D] This is a top view showing another installation configuration of the ventilation duct according to Embodiment 2. [Figure 14] This is a conceptual diagram showing one aspect of a ventilation structure that utilizes the space above the ceiling after a building renovation according to Embodiment 3. [Figure 15] This is a conceptual diagram showing another embodiment of the ventilation structure that utilizes the space above the ceiling after renovation of a building according to Embodiment 3. [Figure 16] This is a cross-sectional view illustrating a ventilation structure that utilizes the space above the ceiling after renovation of a building according to another embodiment. [Figure 17] This is a top view illustrating the configuration of a ventilation duct according to another embodiment. [Figure 18] This is a cross-sectional view illustrating the configuration of an indoor space, including a toilet room, that is subject to renovation in a building according to another embodiment. [Figure 19] This cross-sectional view illustrates the configuration of an indoor space, including a toilet room, after renovation of a building according to another embodiment. [Modes for carrying out the invention]

[0032] The following exemplary embodiments will be described in detail with reference to the drawings. In the following embodiments, the ventilation structure for a building according to the present invention will be described using the application of the present invention to an indoor space including a living room as an example. The drawings are for conceptual explanation of the present invention. Therefore, in order to facilitate understanding of the present invention, dimensions, ratios, or numbers may be exaggerated or simplified in the drawings.

[0033] Embodiment 1 The building renovation method according to this embodiment 1 is used in a residential building to replace a door / window device 10 installed in a partition wall W1 separating adjacent corridors S1 and bedrooms S2, as shown in Figure 1, from a ventilated type to a sealed type. The residential building may be a single unit in an apartment building or other multi-unit dwelling, or a detached house. The residential building includes a corridor S1 and a bedroom S2. Corridor S1 is an example of a first usable space. Bedroom S2 is an example of a second usable space.

[0034] <Building structure before renovation> The corridor S1 and bedroom S2 are adjacent to each other in the indoor space IS, separated by a partition wall W1. The partition wall W1 separates the corridor S1 and bedroom S2. An opening 5 is provided in the partition wall W1. A doorway 4, through which people can pass, is formed in the wall body 3 of the partition wall W1, excluding the opening 5. The opening 5 is constructed by a joinery device 10 installed inside the doorway 4. The joinery device 10 before the renovation was the first joinery device 10A. The first joinery device 10A is configured for ventilation. Furthermore, the first joinery device 10A has lower sound insulation performance and is more susceptible to sound transmission compared to the second joinery device 10B, which will be described later.

[0035] As shown in Figure 3, the first door device 10A is a single-leaf door and has a door frame 11 and a door body 15. The door frame 11 is an example of a door frame. The door body 15 is an example of a door. The door frame 11 is a three-sided frame having a pair of vertical frames and a top frame, and it defines the opening 5. Door stops 12 are provided on the mutually opposing sides of the pair of vertical frames in the door frame 11 and on the bottom surface of the top frame.

[0036] The door body 15 is an opening and closing mechanism that opens and closes the opening 5 inside the door frame 11. The door body 15 is attached to the door frame 11 via hinges 14 and the like, and is designed to open towards the bedroom S2. The hinges 14 are provided in pairs, one above the other. Each pair of hinges 14 consists of a first hinge piece 14a provided on the door frame 11 and a second hinge piece 14b provided on the door body 15. On the upper hinge 14, the first hinge piece 14a is positioned above the second hinge piece 14b. On the lower hinge 14, the second hinge piece 14b is positioned above the first hinge piece 14a.

[0037] An undercut, or ventilation opening 13, is provided on the lower side of the door body 15 to allow air to circulate. The ventilation opening 13 consists of a gap formed between the lower end surface of the door body 15 and the floor FL. The first door device 10A is configured to form the ventilation opening 13 on the lower side of the door body 15 even when the door body 15 is closed. This ventilation opening 13 is effective as a ventilation path P for a 24-hour ventilation system between the corridor S1 and the bedroom S2.

[0038] As shown in Figure 1, the corridor S1 constitutes the passage in front of the bedroom S2. As shown in Figure 2, the ceiling CL of the corridor S1 is formed by the first ceiling material 20. The ceiling CL of the bedroom S2 is formed by the second ceiling material 30. For example, both the first ceiling material 20 and the second ceiling material 30 are constructed by applying wallpaper to the surface of gypsum board. The first ceiling material 20 and the second ceiling material 30 may each be constructed by attaching and integrating a rock wool ceiling finishing material to the surface of gypsum board, or any other arbitrary configuration may be adopted.

[0039] An attic space AS is formed above the ceilings of the bedroom S2 and the corridor S1. The attic space AS extends continuously above the first ceiling material 20 and above the second ceiling material 30. The cavity height H of the attic space AS is, for example, 250 mm to 1000 mm. The attic space AS is provided with structural members 50 that constitute the ceiling framework, such as beams, joists, and hangers, and sound-absorbing panels 51 made of sound-absorbing wool or the like. The cavity height H of the attic space AS is not limited to the above dimensions, as long as there is enough space to house the sound-absorbing duct 61.

[0040] As shown in Figure 1, bedroom S2 is a space enclosed by a partition wall W1, a rear wall W2 opposite the partition wall W1, a pair of side walls W3 located on both the left and right sides when viewed from the opening 5 toward the rear wall W2 (only one side wall W3 is shown in Figure 1), the ceiling CL, and the floor FL. In addition to bedding 31 and lighting equipment 32, bedroom S2 is equipped with an air supply device 33.

[0041] The air supply device 33 is an example of a ventilation system. The air supply device 33 consists of, for example, an air supply fan and is installed, for example, on the upper part of the rear wall W2. When the air supply device 33 is driven, its air supply operation causes air from the bedroom S2 to flow out into the corridor S1 through the vent 13 located below the door body 15, as shown by the dashed arrow in Figure 1. This ventilation of the bedroom S2 is included in the ventilation path of the 24-hour ventilation system. Here, an electric fan is given as an example of the air supply device 33, but a ventilation opening without an electric fan may also be used as a ventilation system.

[0042] <Building renovation methods> In the renovation of the building according to this embodiment, the first door and window device 10A with ventilation specifications described above is replaced with a second door and window device 10B with a sealed specification. If only the door and window device 10 is replaced in this way, the airflow between the corridor S1 and the bedroom S2 will be blocked. Therefore, in order to secure the ventilation path P of the 24-hour ventilation system between the corridor S1 and the bedroom S2, construction work to install a new ventilation structure 1 using the space above the ceiling AS is carried out in conjunction with the replacement of the door and window device 10.

[0043] The building renovation method includes a door and window replacement process and a ventilation structure installation process. The door and window replacement process corresponds to the first process. The door and window replacement process and the ventilation structure installation process may be performed either before or after the door and window replacement process. In the building renovation method of this embodiment, the door and window replacement process and the ventilation structure installation process are carried out together.

[0044] <Door and window replacement process> In the door replacement process, the first door device 10A is replaced with the second door device 10B. As shown in Figure 5, the second door device 10B is configured to be airtight, sealing the opening 5 on all four sides when closed. The door stopper 12 and the door body 15 of the second door device 10B differ from those of the first door device 10A. Therefore, in the door replacement process in this example, the door frame 11 of the existing first door device 10A is retained and used, and the door stopper 12 and the door body 15 are replaced to construct the second door device 10B.

[0045] In the door replacement process, the door stop 12 and door body 15, which constitute the second door device 10B, are prepared in advance. 10B The door stopper 12, which forms the door, has a first packing to make it airtight between it and the door body 15. 16 (Shown with diagonal hatching in Figure 5; the same applies in Figure 4) is provided. The door body 15, which constitutes the second joinery device 10B, is a semi-airtight door that maintains the airtightness of the opening 5. A movable second packing 17 (shown with cross-hatching in Figure 5) and an interlocking mechanism are incorporated into the lower end of the door body 15.

[0046] The second packing 17 is made of a rubber seal that is provided to match the entire width of the lower end of the door body 15. The interlocking mechanism is configured to move the second packing 17 up and down in conjunction with the opening and closing operation of the door body 15. Specifically, the interlocking mechanism lowers the second packing 17 when the door body 15 is closed to seal the gap between the door body 15 and the floor FL, and raises the second packing 17 when the door body 15 is opened to allow the door body 15 to open smoothly.

[0047] In the door replacement process, first, the door body 15 of the first door device 10A is placed in a half-open position, the shaft cover of the upper hinge piece 14a of the door frame 11 is removed, and the shaft attached to the hinge piece 14a is slid upward to detach it from the upper hinge piece 14b of the door body 15. Next, the door body 15 is tilted and lifted with both hands, and the shaft attached to the lower hinge piece 14b of the door body 15 is detached from the lower hinge piece 14a of the door frame 11, thereby removing the door body 15 from the door frame 11.

[0048] Next, the door stop 12 of the first joinery device 10A is removed from the door frame 11. Then, as shown in Figure 4, the door stop 12 with the first packing 16 is attached to the door frame 11 in place of the door stop 12 of the first joinery device 10A.

[0049] Then, with the shaft attached to the upper hinge piece 14b of the door frame 11 raised, the door body 15 of the second joinery device 10B is tilted, and the shaft attached to the lower hinge piece 14b of the door body 15 is inserted into the lower hinge piece 14a of the door frame 11, so that the lower hinge piece 14b of the door body 15 rests on top of the lower hinge piece 14a of the door frame 11. Then, the upper hinge piece 14b of the door body 15 is aligned with the upper hinge piece 14a of the door frame 11 in a vertically corresponding position, and the shaft attached to the upper hinge piece 14a of the door frame 11 is slid downward and inserted into the upper hinge piece 14b of the door body 15. After that, the shaft cover is placed over the upper hinge piece 14a of the door frame 11 and attached.

[0050] In this way, as shown in Figure 5, the first joinery device 10A is replaced with the second joinery device 10B, and the second joinery device 10B forms the opening 5 of the partition wall W1. The second joinery device 10B does not have an undercut that forms a ventilation opening when the opening 5 is closed, unlike the first joinery device 10A, and when the opening 5 is closed, it blocks the flow of air through the opening 5 between the corridor S1 and the bedroom S2. In addition, the second joinery device 10B has relatively high sound insulation performance and is less permeable to sound. The second joinery device 10B in this example has sound insulation performance that reduces the sound pressure level by 20 dB or more at a frequency of 500 Hz.

[0051] <Ventilation structure creation process> The ventilation structure installation process is carried out in the middle of the door replacement process. Specifically, the ventilation structure installation process starts after the door body 15 of the first door device 10A is removed and is carried out with the door body 15 still removed. In the ventilation structure installation process, a ventilation structure 1 is installed to allow air to circulate between the corridor S1 and the bedroom S2 using the space above the ceiling AS. For the installation of the ventilation structure 1, a sound-absorbing duct 61, a first ventilation grille 40A, and a second ventilation grille 40B are prepared in advance.

[0052] As shown in Figure 6, the sound-absorbing duct 61 is a cylindrical duct component. The sound-absorbing duct 61 is constructed including a sound-absorbing material 62, which attenuates sound propagating inside. Furthermore, the sound-absorbing duct 61 is flexible, and its shape in the longitudinal direction can be changed by curving, etc., and it is configured to be elastically deformable in the radial direction.

[0053] Specifically, the sound-absorbing duct 61 comprises a sound-absorbing material 62, an exterior material 63, a reinforcing material 64, and an interior lining material 65. The sound-absorbing material 62 is provided around the entire circumference and along the entire length of the sound-absorbing duct 61. The sound-absorbing material 62 is made of, for example, glass wool. The exterior material 63 is provided around the outer circumference of the sound-absorbing material 62 and constitutes the outermost layer of the sound-absorbing duct 61. The exterior material 63 is made of, for example, a polyolefin film.

[0054] The reinforcing material 64 is provided on the inner circumference of the sound-absorbing duct 61. The reinforcing material 64 is composed of spiral-shaped wire 64a. The wire 64a is made of, for example, a metal wire such as galvanized copper wire or a resin wire. The reinforcing material 64 constitutes a tension coil spring, and when a tensile force is applied in its longitudinal direction, it can be stretched to a length corresponding to the magnitude of the tensile force within the range of its elastic limit, and is maintained in a state where an elastic recovery force is generated.

[0055] The lining material 65 is provided on the inner circumference of the reinforcing material 64. The lining material 65 is made of a nonwoven fabric, such as polyester nonwoven fabric. The lining material 65 is breathable and allows sound to pass through. Therefore, sound propagating inside the sound-absorbing duct 61 can be attenuated by the sound-absorbing material 62. Note that the sound-absorbing duct 61 does not necessarily have a lining material 65. In this case, the sound-absorbing material 62 is exposed on the inner surface of the sound-absorbing duct 61.

[0056] The sound-absorbing duct 61 has a first end 61a and a second end 61b. The first end 61a is one end (one end) in the longitudinal direction of the sound-absorbing duct 61. The second end 61b is the other end (the other end) in the longitudinal direction of the sound-absorbing duct 61. The outer diameter R2 of the first end 61a and the outer diameter R4 of the second end 61b of the sound-absorbing duct 61 are of equal diameter and are both smaller than the outer diameter R1 of the middle portion of the sound-absorbing duct 61 in the longitudinal direction.

[0057] The sound-absorbing duct 61 is prepared to be longer than the distance between the center of the first opening 26 and the center of the second opening 36, which will be described later. In this example, the length of the sound-absorbing duct 61 is 1500 mm. The opening diameter r (nominal diameter) of the sound-absorbing duct 61 is, for example, 200 mm in diameter. With a sound-absorbing duct 61 having such a length and opening diameter, it is possible to achieve both ventilation performance and sound reduction performance in the ventilation duct 60.

[0058] The same ventilation grille 40 is used for both the first ventilation grille 40A and the second ventilation grille 40B. As shown in Figures 7 and 8, the ventilation grille 40 is composed of a pipe guide 41 and a grille body 46. The pipe guide 41 of the first ventilation grille 40A corresponds to a component of the first ventilation grille 40A. The pipe guide 41 of the second ventilation grille 40B corresponds to a component of the second ventilation grille 40B.

[0059] The pipe guide 41 has a guide portion 42 and a flange portion 43. The guide portion 42 is formed in a cylindrical shape and extends to the back side of the ventilation grille 40. The flange portion 43 spreads outward from the end of the guide portion 42 on the grille body 46 side and is formed in a rectangular shape in plan view. Screw holes 44 are formed at each of the four corners of the flange portion 43.

[0060] The grill body 46 is fitted and attached to the front side of the flange portion 43. The grill body 46 has a ventilation section 47 formed in a cross-shaped grid. Multiple ventilation holes 48 are formed in the ventilation section 47 in a matrix pattern, each rectangular in shape, forming the spaces between the grid. The ventilation section 47 allows air to circulate between the front exterior of the grill body 46 and the inside of the guide portion 42 of the pipe guide 41 through each ventilation hole 48.

[0061] The ventilation structure construction process includes a ceiling hole drilling process, a cut surface treatment process, and a duct installation process. The ceiling hole drilling process corresponds to the second process. The cut surface treatment process corresponds to the fourth process. The duct installation process corresponds to the third process.

[0062] <Ceiling hole drilling process> In the ceiling hole drilling process, a first opening 26 is formed in the first ceiling material 20, and a second opening 36 is formed in the second ceiling material 30.

[0063] Specifically, first, the formation locations of the first opening 26 and the second opening 36 are determined. The distance D between the center of the first opening 26 and the center of the second opening 36 should preferably not be too short relative to the total length of the sound-absorbing duct 61. This is because if the distance D is too short relative to the total length of the sound-absorbing duct 61, it will be difficult to connect both ends of the sound-absorbing duct 61 to the first opening 26 and the second opening 36, and there is a concern that the sound-absorbing duct 61 will have unnaturally constricted sections, where air may stagnate or condensation may easily occur. For example, when using a sound-absorbing duct 61 with a length of 1500 mm, the distance D between the center of the first opening 26 and the center of the second opening 36 should be 700 mm to 1000 mm.

[0064] At this time, the locations for forming the first opening 26 and the second opening 36 are determined by considering the distance between the ventilation grille 40 and the wall surface, so that the ventilation grille 40 attached to the lower surfaces of the first ceiling material 20 and the second ceiling material 30 do not interfere with the wall surface including the partition wall W1, as will be described later. Then, as shown in Figure 9A, the center position of the location for forming the first opening 26 in the first ceiling material 20 and the center position of the location for forming the second opening 36 in the second ceiling material 30 are marked with a marker or pen.

[0065] Next, as shown in Figure 9B, a first opening 26 is formed in the first ceiling material 20 in a circular shape centered on the position marked with a marker MK. At this time, the first opening 26 is formed with an inner diameter R3 that is larger than the diameter R2 of the first end 61a of the sound-absorbing duct 61 and smaller than the diameter R1 in the middle of the sound-absorbing duct 61 in the longitudinal direction. In this example, the first opening 26 is formed to a size of 250 mm in diameter. A hole saw or downlight cutter is used to form the first opening 26. The first opening 26 opens to the corridor S1 and the space above the ceiling AS.

[0066] Furthermore, a second opening 36 is formed in a circular shape on the second ceiling material 30, centered on the position marked with a marker MK. At this time, the second opening 36 is formed with an inner diameter R5 that is larger than the diameter R4 of the second end 61b of the sound-absorbing duct 61 and smaller than the diameter R1 in the middle of the sound-absorbing duct 61 in the longitudinal direction. In this example, the second opening 36 is formed to the same size as the first opening 26, with a diameter of 250 mm. A hole saw or downlight cutter is also used to form the second opening 36. The second opening 36 opens to the bedroom S2 and the space above the ceiling AS.

[0067] <Cut surface treatment process> In the cut surface processing step, the first cover member 71 is attached to the inner periphery of the first opening 26 of the first ceiling material 20. Also, the second cover member 72 is attached to the inner periphery of the second opening 36 of the second ceiling material 30. In this example, airtight waterproof tape is used as the first cover member 71 and the second cover member 72.

[0068] Specifically, as shown in Figure 9C, an airtight waterproof tape, serving as the first cover member 71, is attached to the inner periphery of the first opening 26 of the first ceiling material 20 in lengths of approximately 50 mm. The airtight waterproof tape is used to wrap around the periphery of the first opening 26 of the first ceiling material 20 so that the cut surface of the first ceiling material 20 is not visible, covering the area spanning the upper and lower surfaces of the periphery of the ceiling material 20 in a U-shape. In this way, the first cover member 71 is attached to the inner periphery of the first opening 26 of the first ceiling material 20 in an annular manner such that its inner diameter is larger than the outer diameter R2 of the first end 61a of the sound-absorbing duct 61. To achieve this, during the ceiling hole drilling process, the first opening 26 should be formed while anticipating what the inner diameter of the first cover member 71 attached to the inner periphery of the first opening 26 will be.

[0069] Furthermore, an airtight waterproof tape, serving as the second cover member 72, is similarly attached to the inner circumferential surface of the second opening 36 of the second ceiling material 30, and the second cover member 72 is attached in a ring shape such that its inner diameter is larger than the outer diameter R4 of the second end 61b of the sound-absorbing duct 61. To achieve this, during the ceiling hole drilling process, the second opening 36 should be formed while anticipating what the inner diameter of the second cover member 72 attached to the inner circumferential edge of the second opening 36 will be. In this way, by covering the cut surface of the first ceiling material 20 with the first cover member 71 and the cut surface of the second ceiling material 30 with the second cover member 72, it is possible to prevent dust from falling from each cut surface and damage to each cut surface.

[0070] <Duct installation process> In the duct installation process, a ventilation duct 60 is installed in the ceiling space AS to connect the first opening 26 and the second opening 36 and to allow air to circulate between the corridor S1 and the bedroom S2. In this example, the aforementioned flexible sound-absorbing duct 61 is used to install the ventilation duct 60. The entire ventilation duct 60 is then composed of the sound-absorbing duct 61. The ventilation duct 60 is a pipe that connects the first opening 26 and the second opening 36 and allows air to circulate between the corridor S1 and the bedroom S2.

[0071] Specifically, first, the sound-absorbing duct 61 is inserted into the ceiling space AS through the first opening 26 or the second opening 36. For example, as shown in Figure 9D, the second end 61b of the sound-absorbing duct 61 is inserted from the corridor S1 into the first opening 26, where the first cover member 71 is attached to the inner periphery, and the sound-absorbing duct 61 is inserted through the first opening 26. Then, with one arm inside the sound-absorbing duct 61, the sound-absorbing duct 61 is pushed into the ceiling space AS with both hands so that the second end 61b of the sound-absorbing duct 61 reaches the second opening 36.

[0072] Next, the second end 61b of the sound-absorbing duct 61 is pulled out into the bedroom S2 through the second opening 36, to which the second cover member 72 is attached to the inner periphery, and the sound-absorbing duct 61 is inserted through the second opening 36. Furthermore, as shown in Figure 9E, the portion of the sound-absorbing duct 61 including the first end 61a is extended approximately 150 mm from the ceiling space AS through the first opening 26 into the corridor S1. Also, the portion of the sound-absorbing duct 61 including the second end 61b is extended approximately 150 mm from the ceiling space AS through the second opening 36 into the bedroom S2.

[0073] Next, the pipe guide 41 of the first ventilation grille 40A is attached to the first end 61a of the sound-absorbing duct 61. At this time, the pipe guide 41 of the first ventilation grille 40A is separated from the grille body 46. As shown in Figure 9F, the guide portion 42 of the pipe guide 41 is inserted into the first end 61a of the sound-absorbing duct 61, and the first end 61a of the sound-absorbing duct 61 and the pipe guide 41 are fixed together with the connecting member 73.

[0074] In this example, airtight and waterproof tape is used as the joining member 73, and the airtight and waterproof tape is wrapped twice around the connection between the first end 61a of the sound-absorbing duct 61 and the pipe guide 41. For example, for the first wrap, the airtight and waterproof tape is applied in an L-shape with lengths of approximately 50 mm. For the second wrap, the airtight and waterproof tape is applied circumferentially over the L-shaped overlap of the first wrap to eliminate any gaps between the first wraps of airtight and waterproof tape.

[0075] Furthermore, the pipe guide 41 of the second ventilation grille 40B is attached to the second end 61b of the sound-absorbing duct 61. At this time, the pipe guide 41 of the second ventilation grille 40B is separated from the grille body 46. The pipe guide 41 of the second ventilation grille 40B is also fixed to the second end 61b of the sound-absorbing duct 61 using airtight waterproof tape as a joining member 73, in the same procedure as for fixing the pipe guide 41 to the first end 61a of the sound-absorbing duct 61 as described above.

[0076] Subsequently, the flange portion 43 of the first ventilation grille 40A is taken and the portion of the sound-absorbing duct 61 on the side of the first end 61a that has been pulled out from the first opening 26 is pushed up and inserted into the ceiling space AS, and as shown in Figure 9G, the flange portion 43 is placed against the lower surface of the first ceiling material 20 so as to cover the first cover member 71 and the first opening 26. In this state, screws 45 such as tapping screws or wood screws are inserted through each screw hole 44 of the flange portion 43 and the flange portion 43 is screwed to the first ceiling material 20, thereby fixing the pipe guide 41 to the lower surface of the first ceiling material 20.

[0077] At this time, a first gap g1 is formed between the inner edge of the first opening 26 of the first ceiling material 20 and the first end 61a of the sound-absorbing duct 61 (see Figure 10). Then, the grill body 46 of the first ventilation grill 40A is fitted and fixed into the pipe guide 41. In this way, the first ventilation grill 40A is attached to the lower surface of the first ceiling material 20 so as to cover the first gap g1 formed on the outer circumference of the first end 61a of the sound-absorbing duct 61. When the ceiling CL of the corridor S1 is viewed, the first cover member 71 and the first gap g1 are concealed by the first ventilation grill 40A and are not visible.

[0078] Furthermore, the flange portion 43 of the second ventilation grille 40B is held and the portion of the sound-absorbing duct 61 on the second end 61b side that has been pulled out from the second opening 36 is pushed up and inserted into the ceiling space AS, and the flange portion 43 is positioned against the lower surface of the second ceiling material 30 so as to cover the second cover member 72 and the second opening 36. In this state, screws 45 such as tapping screws or wood screws are inserted through each screw hole 44 of the flange portion 43, and the flange portion 43 is screwed to the second ceiling material 30, thereby fixing the pipe guide 41 to the lower surface of the second ceiling material 30.

[0079] At this time, a second gap g2 is formed between the inner periphery of the second opening 36 of the second ceiling material 30 and the second end 61b of the sound-absorbing duct 61 (see Figure 10). Then, the grill body 46 of the second ventilation grill 40B is fitted and fixed into the pipe guide 41. In this way, the second ventilation grill 40B is attached to the lower surface of the second ceiling material 30 so as to cover the second gap g2 formed on the outer circumference of the second end 61b of the sound-absorbing duct 61. When looking at the ceiling CL of the bedroom S2, the second cover member 72 and the second gap g2 are concealed by the second ventilation grill 40B and are not visible.

[0080] As described above, an air discharge section 25 consisting of a first ventilation grille 40A and a first opening 26 is installed in the ceiling CL of the corridor S1, as shown in Figures 10 and 11. An air intake section 35 consisting of a second ventilation grille 40B and a second opening 36 is installed in the ceiling CL of the bedroom S2. A ventilation duct 60 connecting the air intake section 35 and the air discharge section 25 is installed in the space above the ceiling AS. In this example, the ventilation duct 60 is installed so as to extend straight between the first opening 26 and the second opening 36. The ventilation duct 60 may also be installed bent to form a U-shape, M-shape, or S-shape that forms a mountain shape when viewed horizontally or from above.

[0081] These air intake section 35, air discharge section 25, and ventilation duct 60 constitute a ventilation structure 1 for circulating air between the corridor S1 and the bedroom S2. Therefore, even if the second door / window device 10B seals the opening 5, when the air supply device 33 in the bedroom S2 is activated, the air supply operation causes air from inside the bedroom S2 to flow into the ventilation duct 60 through the air intake section 35, as shown by the dashed arrow in Figure 11, and then flow out into the corridor S1 from the air discharge section 25.

[0082] The effective opening area A of the ventilation duct 60 is 100 cm². 2 That concludes the explanation. The effective opening area A of the ventilation duct 60 is approximately equal to the equivalent gap area and is calculated based on the amount of airflow when the pressure difference across the ventilation duct 60, that is, the pressure difference between the first end 61a and the second end 61b of the ventilation duct 60, is 9.8 Pa. Specifically, the effective opening area A of the ventilation duct 60 is determined by the following formula. A = 10000 / 3600 × (ρ / 2) 1 / 2 ×a×ΔP 1 / n-1 / 2 Here, ρ is the density of air (1.205 [kg / m³]). 3 ]) is the air permeability [(m 3 / h) / Pa 1 / n ]. ΔP is the pressure difference across the ventilation duct 60 (i.e., 9.8 Pa). n is the gap characteristic value (dimensionless).

[0083] Furthermore, sound entering from either the corridor S1 or bedroom S2 propagates within the ventilation duct 60, but is reduced by the sound-absorbing material 62 during the propagation process from one corridor S1 to the other. After the renovation, a sound insulation effect is obtained that reduces the sound pressure level between corridor S1 and bedroom S2 by 20 dB or more at a frequency of 500 Hz. This sound insulation effect is measured as the difference in sound pressure levels between corridor S1 and bedroom S2, in accordance with JIS A 1417:2000. The second door and window device 10B has sound transmission loss characteristics that allow the above sound insulation effect to be obtained. The ventilation duct 60 is configured with a length and opening diameter that allows the above sound insulation effect to be obtained while also satisfying the effective opening area A.

[0084] -Features of Embodiment 1- In the building renovation method of this Embodiment 1, the fitting device 10 provided at the opening 5 of the partition wall W1 that separates the corridor S1 and the bedroom S2 is replaced from the first fitting device 10A with a ventilation specification to the second fitting device 10B with a sealed specification. According to this, it is possible to suppress the leakage of sound from one of the corridor S1 and the bedroom S2 to the other through the opening 5. Then, after forming the first opening 26 in the first ceiling member 20 that forms the ceiling CL of the corridor S1 and forming the second opening 36 in the second ceiling member 30 that forms the ceiling CL of the bedroom S2, a ventilation duct 60 that connects the first opening 26 and the second opening 36 is provided in the ceiling space AS using a sound-absorbing duct 61. Air can be circulated through the ventilation duct 60. Further, since the sound-absorbing duct 61 is configured to include a sound-absorbing material 62, it is possible to attenuate the sound propagating in the ventilation duct 60 and suppress the leakage of sound from one of the corridor S1 and the bedroom S2 to the other through the ventilation duct 60. Therefore, while improving the sound insulation between the corridor S1 and the bedroom S2, it is possible to secure the ventilation path P between the corridor S1 and the bedroom S2. As a result, while using the existing ventilation equipment as it is, it is possible to reduce the review of the ventilation path plan of the 24-hour ventilation system.

[0085] In the building renovation method of this Embodiment 1, the sound-absorbing duct 61 used for the ventilation duct 60 has flexibility. According to this, it is easy to avoid interference with structural members 50 such as beams existing in the ceiling space AS by bending the sound-absorbing duct 61 or the like. Therefore, the workability when installing the ventilation duct 60 in the ceiling space AS is good.

[0086] In the building renovation method of this Embodiment 1, the effective opening area of the ventilation duct 60 is 100 cm 2As described above, the necessary effective opening area for the ventilation path of the 24-hour ventilation system can be secured between the corridor S1 and the bedroom S2. Therefore, the ventilation path P provided by the ventilation duct 60 can be suitably used as the ventilation path for the 24-hour ventilation system. Furthermore, after the renovation, a sound insulation effect equivalent to the sound insulation performance of the second door / window device 10B can be obtained between the corridor S1 and the bedroom S2. This makes it possible to achieve both ventilation and sound insulation between the corridor S1 and the bedroom S2.

[0087] In this embodiment 1 of the building renovation method, the first opening 26 is formed with an inner diameter R3 that is larger than the outer diameter R2 of the first end 61a of the sound-absorbing duct 61 and smaller than the outer diameter R1 of the middle of the sound-absorbing duct 61 in the longitudinal direction. Compared to the case where the first opening 26 is formed with an inner diameter larger than the outer diameter R1 of the middle of the sound-absorbing duct 61 in the longitudinal direction, and compared to the case where the first opening 26 is formed with a smaller diameter and the first opening 26 is formed with an inner diameter smaller than the outer diameter R2 of the first end 61a of the sound-absorbing duct 61, the load on the sound-absorbing duct 61 when inserting the sound-absorbing duct 61 into the first opening 26 can be reduced. This is advantageous for making the first ventilation grille 40A relatively small and for improving the workability when installing the ventilation duct 60 in the ceiling space AS. Furthermore, the first ventilation grille 40A is attached to the lower surface of the first ceiling material 20 so as to cover the first gap g1 between the first end 61a of the sound-absorbing duct 61 and the inner periphery of the first opening 26. This conceals the first gap g1 with the first ventilation grille 40A, improving the appearance of the ceiling CL of the corridor S1.

[0088] In this embodiment 1 of the building renovation method, the second opening 36 is formed with an inner diameter R5 that is larger than the outer diameter R4 of the second end 61b of the sound-absorbing duct 61 and smaller than the outer diameter R1 in the middle of the sound-absorbing duct 61 in the longitudinal direction. Compared to the case where the second opening 36 is formed with an inner diameter larger than the outer diameter R1 in the middle of the sound-absorbing duct 61 in the longitudinal direction, and compared to the case where the second opening 36 is formed with a smaller diameter and the inner diameter is smaller than the outer diameter R4 of the second end 61b of the sound-absorbing duct 61, the load on the sound-absorbing duct 61 when inserting it into the second opening 36 can be reduced. This is advantageous for making the second ventilation grille 40B relatively small and for improving the workability when installing the ventilation duct 60 in the ceiling space AS. Furthermore, the second ventilation grille 40B is attached to the lower surface of the second ceiling material 30 so as to cover the second gap g2 between the second end 61b of the sound-absorbing duct 61 and the inner periphery of the second opening 36. This conceals the second gap g2, improving the appearance of the ceiling CL of the bedroom S2.

[0089] In this embodiment 1 of the building renovation method, a first cover member 71 is attached to the inner periphery of the first opening 26 of the first ceiling material 20, and a sound-absorbing duct 61 is inserted from the corridor S1 to the ceiling space AS through the first opening 26 with the first cover member 71 attached to its inner periphery. As a result, when the sound-absorbing duct 61 is inserted through the first opening 26, the first cover member 71 is positioned between the inner periphery of the first opening 26 and the sound-absorbing duct 61, which prevents the sound-absorbing duct 61 from being damaged by directly hitting and rubbing against the inner periphery of the first opening 26, and also prevents damage to the inner periphery of the first opening 26 and the falling of fragments.

[0090] In this embodiment 1 of the building renovation method, the first cover member 71 is attached annularly to the inner periphery of the first opening 26 of the first ceiling material 20 such that its inner diameter is larger than the outer diameter R2 of the first end 61a of the sound-absorbing duct 61. This makes it relatively easy to insert the sound-absorbing duct 61 from the corridor S1 into the ceiling space AS through the first opening 26, and reduces the load on the sound-absorbing duct 61 when inserting it into the first opening 26.

[0091] In this embodiment 1 of the building renovation method, a second cover member 72 is attached to the inner periphery of the second opening 36, and a sound-absorbing duct 61 is inserted from the ceiling space AS to the bedroom S2 through the second opening 36 with the second cover member 72 attached to its inner periphery. As a result, when the sound-absorbing duct 61 is inserted through the second opening 36, the second cover member 72 is positioned between the inner periphery of the second opening 36 and the sound-absorbing duct 61, which prevents the sound-absorbing duct 61 from being damaged by directly contacting and rubbing against the inner periphery of the second opening 36, and also prevents damage to the inner periphery of the second opening 36 and the falling of fragments.

[0092] In this embodiment 1 of the building renovation method, the second cover member 72 is attached in a ring shape to the inner periphery of the second opening 36 of the second ceiling material 30 such that its inner diameter is larger than the outer diameter R4 of the second end 61b of the sound-absorbing duct 61. This makes it relatively easy to pull the sound-absorbing duct 61 from the ceiling space AS to the bedroom S2 through the second opening 36, and reduces the load on the sound-absorbing duct 61 when inserting it into the second opening 36.

[0093] In this embodiment 1 of the building renovation method, the entire ventilation duct 60 is composed of a sound-absorbing duct 61. With this, a first opening 26 is formed in the first ceiling material 20 and a second opening 36 in the second ceiling material 30, and the sound-absorbing duct 61 is placed in the space above the ceiling AS. The first end 61a and the second end 61b are connected to the first opening 26 and the second opening 36 using the first ventilation grille 40A and the second ventilation grille 40B, allowing the ventilation duct 60 to be installed in the space above the ceiling AS. Furthermore, the installation of such a ventilation duct 60 can be completed in the corridor S1 and bedroom S2 without removing the first ceiling material 20 and the second ceiling material 30.

[0094] Embodiment 2 The building renovation method according to this second embodiment differs from that of the first embodiment in the configuration of the ventilation duct 60 installed in the ceiling space AS. In this embodiment, apart from the configuration of the ventilation duct 60, the ventilation structure 1 opened during the building renovation is configured in the same way as in the first embodiment. Therefore, only the ventilation duct 60 with the different configuration will be described, and the same components will be left to the description of the first embodiment, and their detailed explanation will be omitted.

[0095] In this second embodiment of building renovation, the ventilation duct 60 is constructed using a first elbow 81, a second elbow 82, and a sound-absorbing duct 61, as shown in Figure 12. The first elbow 81 is an example of a first curved member. The second elbow 82 is a second curved section. Material This is one example. The first elbow 81 and the second elbow 82 are joints that are bent in an L-shape so that the openings at both ends face in directions that are 90° different, and they constitute the curved section of the ventilation duct 60.

[0096] The first elbow 81 is connected to the first opening 26 of the first ceiling material 20. The guide portion 42 of the first ventilation grille 40A is fitted and fixed to the first open end 81a, which forms one end opening of the first elbow 81. The first open end 81a of the first elbow 81 is inserted through the first opening 26. The first open end 81a of the first elbow 81 may be directly fixed to the first ceiling material 20. The second open end 81b, which forms the other end opening of the first elbow 81, opens horizontally in the ceiling space AS.

[0097] The second elbow 82 is connected to the second opening 36 of the second ceiling material 30. The guide portion 42 of the second ventilation grille 40B is fitted and fixed to the third open end 82a, which forms one end opening of the second elbow 82. The third open end 82a of the second elbow 82 is inserted through the second opening 36. The third open end 82a of the second elbow 82 may be directly fixed to the second ceiling material 30. The fourth open end 82b, which forms the other end opening of the second elbow 82, opens horizontally in the ceiling space AS.

[0098] The sound-absorbing duct 61 is used to connect the first elbow 81 and the second elbow 82. The second open end 81b of the first elbow 81 is fitted and secured to the first end 61a of the sound-absorbing duct 61. The fourth open end 82b of the second elbow 82 is fitted and secured to the second end 61b of the sound-absorbing duct 61. Alternatively, the first end 61a of the sound-absorbing duct 61 may be fitted to the second open end 81b of the first elbow 81, or the second end 61b of the sound-absorbing duct 61 may be fitted to the fourth open end 82b of the second elbow 82.

[0099] As shown in Figure 13A, the second open end 81b of the first elbow 81 and the fourth open end 82b of the second elbow 82 face each other in a corresponding manner. The sound-absorbing duct 61 is installed to extend in a straight line between the first elbow 81 and the second elbow 82.

[0100] Furthermore, the second open end 81b of the first elbow 81 and the fourth open end 82b of the second elbow 82 do not necessarily have to face each other in a corresponding manner.

[0101] For example, as shown in Figure 13B, the second open end 81b of the first elbow 81 and the fourth open end 82b of the second elbow 82 may face the same side in a direction perpendicular to the direction in which the first elbow 81 and the second elbow 82 are adjacent. In this case, the sound-absorbing duct 61 extends in a U-shape when viewed from above in a top view of the space above the ceiling AS. With this installation method of the ventilation duct 60, the sound-absorbing duct 61 is provided at a longer length than when it extends in a straight line, thereby improving the sound reduction performance of the ventilation duct 60.

[0102] Furthermore, as shown in Figure 13C, the second open end 81b of the first elbow 81 and the fourth open end 82b of the second elbow 82 may be oriented in a direction that causes them to tilt toward the same side with respect to the direction in which the first elbow 81 and the second elbow 82 are adjacent to each other. In this case, the sound-absorbing duct 61 extends in a curved shape when viewed from above, looking at the ceiling space AS from above. With this installation method of the ventilation duct 60, it can be installed shorter than when the sound-absorbing duct 61 extends in a U-shape, so that the ventilation duct 60 can be installed in a space-saving manner while obtaining good sound reduction performance from the ventilation duct 60.

[0103] Furthermore, as shown in Figure 13D, the second open end 81b of the first elbow 81 and the fourth open end 82b of the second elbow 82 may be oriented in directions that are inclined opposite to each other with respect to the direction in which the first elbow 81 and the second elbow 82 are adjacent. In this case, the sound-absorbing duct 61 extends in a meandering S-shape when viewed from above in the ceiling space AS. This installation method of the ventilation duct 60 also allows for a shorter installation compared to the case where the sound-absorbing duct 61 extends in a U-shape, thus enabling the ventilation duct 60 to be installed in a space-saving manner while obtaining good sound reduction performance.

[0104] In the building renovation of this second embodiment, during the duct installation process, similar to the first embodiment, a sound-absorbing duct 61 is inserted into the ceiling space AS through the first opening 26 or the second opening 36, and the portion of the sound-absorbing duct 61 including its first end 61a is brought out from the ceiling space AS through the first opening 26 to the corridor S1. The portion of the sound-absorbing duct 61 including its second end 61b is brought out from the ceiling space AS through the second opening 36 to the bedroom S2.

[0105] Next, the second open end 81b of the first elbow 81 is fitted and secured to the first end 61a of the sound-absorbing duct 61, and the pipe guide 41 of the first ventilation grille 40A is attached to the first open end 81a of the first elbow 81. Furthermore, the portion of the sound-absorbing duct 61 on the side of the first end 61a that is pulled out from the first opening 26 is pushed up and inserted into the ceiling space AS together with the first elbow 81. Then, the pipe guide 41 is placed against the lower surface of the first ceiling material 20 and secured with screws. In this way, the first open end 81a of the first elbow 81 is connected to the first opening 26. After that, the grille body 46 is fitted onto the pipe guide 41 to form the first ventilation grille 40A attached to the lower surface of the first ceiling material 20.

[0106] Furthermore, the fourth open end 82b of the second elbow 82 is fitted and fixed to the second end 61b of the sound-absorbing duct 61, and the pipe guide 41 of the second ventilation grille 40B is attached to the fourth open end 82b of the second elbow 82. In addition, the portion of the sound-absorbing duct 61 on the second end 61b side that is pulled out from the second opening 36 is pushed up and inserted into the ceiling space AS together with the second elbow 82. Then, the pipe guide 41 is placed against the lower surface of the second ceiling material 30 and fixed with screws. In this way, the second elbow 82 Third opening end 82b This is connected to the second opening 36. Then, the grill body 46 is fitted into the pipe guide 41 to form the second ventilation grill 40B attached to the lower surface of the second ceiling material 30.

[0107] -Features of Embodiment 2- In this second embodiment of the building renovation method, the ventilation duct 60 is constructed using a first elbow 81, a second elbow 82, and a sound-absorbing duct 61. The first elbow 81 is connected to the first opening 26, and the second elbow 82 is connected to the second opening 36. The sound-absorbing duct 61 is used to connect the first elbow 81 and the second elbow 82. With this configuration, the height required to install the ventilation duct 60 can be controlled by the first elbow 81 and the second elbow 82, making it easier to shape the ventilation duct 60 in the ceiling space AS to the desired shape. As a result, the ventilation duct 60 can be easily accommodated in the ceiling space AS, which has limited headroom.

[0108] Embodiment 3 In this third embodiment of the building renovation method, multiple ventilation ducts 60 are installed in the ceiling space AS. The effective opening area A of each ventilation duct 60 varies depending on the opening diameter and length of the ventilation duct 60. Therefore, while obtaining a sound insulation effect that reduces the sound pressure level between the corridor S1 and the bedroom S2 by 20 dB or more at a frequency of 500 Hz, the effective opening area A of the ventilation duct 60 is 100 cm². 2 The number of ventilation ducts 60 is set as described above. Here, the effective opening area A of all ventilation ducts 60 is 100 cm² in total. 2 The above conditions must be met.

[0109] The effective opening area A of the ventilation duct 60 is 100 cm². 2 To achieve the above, if a sound-absorbing duct 61 with an opening diameter r of 200 mm and a length of 1000 mm to 2000 mm is used as in Embodiment 1 above, only one ventilation duct 60 is needed. However, if a sound-absorbing duct 61 with an opening diameter r of 150 mm and a length of 1000 mm to 2000 mm is used, at least two ventilation ducts 60 are needed. If a sound-absorbing duct 61 with an opening diameter r of 100 mm and a length of 1000 mm to 2000 mm is used, at least three ventilation ducts 60 are needed.

[0110] The following explanation will use the case where three ventilation ducts 60 are installed as an example. In the building renovation method of this embodiment, as shown in Figure 14, three ventilation paths P are formed between the corridor S1 and the bedroom S2, one for each ventilation duct 60. Each ventilation path P consists of an air intake section 35, an air discharge section 25, and a ventilation duct 60. In this example, a sound-absorbing duct 61 with a length of 1000 mm to 2000 mm is used for each ventilation duct 60. The opening diameter r (nominal diameter) of each sound-absorbing duct 61 is, for example, 100 mm in diameter.

[0111] In this example, the inner diameter of the first opening 26 and the size of the first ventilation grille 40A in each air discharge section 25 are smaller than those in Embodiment 1. Also, in this example, the inner diameter of the second opening 36 and the size of the second ventilation grille 40B in each air intake section 35 are smaller than those in Embodiment 1. The inner diameter R3 of the first opening 26 and the inner diameter R5 of the second opening 36 are, for example, 150 mm each.

[0112] The three air discharge sections 25 are arranged in a row on the ceiling CL located in front of the bedroom S2 in the corridor S1. The three air intake sections 35 are arranged in a row on the ceiling CL of the bedroom S2 in the same direction as the three air discharge sections 25. The three ventilation ducts 60 are installed so as to extend parallel to each other in the space above the ceiling AS. In this example, the effective opening area A of the ventilation ducts 60 is 100 cm² in total for the three ventilation ducts 60. 2 The above conditions must be met.

[0113] The three air intake sections 35 and the three air discharge sections 25 do not necessarily have to be arranged in a straight line. For example, as shown in Figure 15, one air intake section 35 may be provided in the center of the ceiling CL of bedroom S2, and the remaining two air intake sections 35 may be provided separately at the two corners on the partition wall W1 side of the ceiling CL of bedroom S2. In this case, the three air discharge sections 25 may be provided in the ceiling CL of corridor S1 in a positional relationship corresponding to the three air intake sections 35.

[0114] In order to create a ventilation structure 1 including three ventilation paths P during building renovation, the ceiling hole drilling process, cut surface processing process, and duct installation process, similar to those in Embodiment 1, should be performed for each ventilation path P during the ventilation structure creation process.

[0115] Other embodiments In the above embodiment 1, a first gap g1 is formed between the first end 61a of the sound-absorbing duct 61 and the inner periphery of the first opening 26 of the first ceiling material 20, and a second gap g2 is formed between the second end 61b of the sound-absorbing duct 61 and the inner periphery of the second opening 36 of the second ceiling material 30, but the embodiment is not limited to this. The first end 61a of the sound-absorbing duct 61 may be in close contact with the inner periphery of the first opening 26 of the first ceiling material 20 or a first cover member 71 attached to that inner periphery. Also, the second end 61b of the sound-absorbing duct 61 may be in close contact with the inner periphery of the second opening 36 of the second ceiling material 30 or a second cover member 72 attached to that inner periphery.

[0116] For example, as shown in Figure 16, a cushioning material with cushioning properties may be used as the first cover member 71, and the cushioning material may be attached in an annular manner to the inner periphery of the first opening 26 such that its inner diameter is smaller than the outer diameter of the first end 61a of the sound-absorbing duct 61, thereby bringing the outer circumferential surface of the first end 61a of the sound-absorbing duct 61 into close contact with the cushioning material. Alternatively, a cushioning material with cushioning properties may be used as the second cover member 72, and the cushioning material may be attached in an annular manner to the inner periphery of the second opening 36 such that its inner diameter is smaller than the outer diameter of the second end 61b of the sound-absorbing duct 61, thereby bringing the outer circumferential surface of the second end 61b of the sound-absorbing duct 61 into close contact with the cushioning material.

[0117] In Embodiment 1 described above, the ventilation duct 60 is assumed to be composed of one sound-absorbing duct 61, but this is not limited to this. The ventilation duct 60 may consist of two or more sound-absorbing ducts 61. For example, as shown in Figure 17, when the ventilation duct 60 is composed of two sound-absorbing ducts 61, the two sound-absorbing ducts 61 can be connected via a pipe joint 85. The same applies to Embodiments 2 and 3 described above.

[0118] In the above embodiment 2, the ventilation duct 60 is configured using a first elbow 81 and a second elbow 82 in addition to the sound-absorbing duct 61, but it is not limited to this. For example, instead of the first elbow 81, the ventilation duct 60 may use a box-shaped chamber member having a pair of openings facing 90° different directions as the first bending member. Also, the ventilation duct 60 is 2Instead of the elbow 82, a box-shaped chamber member having a pair of openings facing 90° apart from each other may be used as the second curved member.

[0119] In the above embodiment 1, circular openings (first opening 26, second opening 36) are formed in the first ceiling material 20 and the second ceiling material 30, respectively, during building renovation, and a sound-absorbing duct 61 is inserted into the ceiling space AS through these openings. However, the invention is not limited to this. For example, as a procedure for inserting a sound-absorbing duct 61 into the ceiling space AS, a rectangular opening with a larger opening area than the first opening 26 is formed in the first ceiling material 20, the sound-absorbing duct 61 is inserted into the ceiling space AS through this opening, and then the sound-absorbing duct 61 is inserted from the first end 61a into the first ceiling material 20, which has the first opening 26 already formed, and the first ceiling material 20 is fitted into the rectangular opening and attached to the ceiling CL of the corridor S1. This procedure can also be performed similarly for the second ceiling material 30, and the sound-absorbing duct 61 may be inserted into the ceiling space AS from the second ceiling material 30 side.

[0120] In embodiments 1 to 3 described above, the building renovation method according to the present invention was explained using the case of an indoor space IS including a bedroom S2 as an example, but it is not limited to this. The present invention can be applied to any indoor space IS where it is necessary to circulate air between a first usable space and a second usable space adjacent to each other via a partition wall W1 that forms an opening 5 with a first ventilated door device 10A.

[0121] For example, as shown in Figure 18, the building renovation method according to the present invention can target an indoor space IS including a toilet room S3 when it is necessary to secure a path for air to flow from the corridor S1 to the toilet room S3. The door and window device 10 before renovation that constitutes the opening 5 in the partition wall W1 is a first door and window device 10A with ventilation specifications. The toilet room S3 is a space surrounded by the partition wall W1, the back wall W2, a pair of side walls W3 (only one side wall W3 is shown in Figure 18), the ceiling CL, and the floor FL.

[0122] Toilet room S3 is equipped with toilet facilities 37 and lighting equipment 32, as well as an exhaust system 38. The exhaust system 38 is an example of ventilation equipment. The exhaust system 38 consists of a ventilation fan such as a direct exhaust type and is installed, for example, on the upper part of the rear wall W2. Toilet room S 3 When the exhaust device 38 is activated, its exhaust operation causes air flowing from living rooms or bedrooms into the corridor S1 to enter the toilet room S3 through the vent 13 located below the door body 15, and then to be exhausted by the exhaust device 38, as shown by the dashed arrow in Figure 18. In other embodiments, the exhaust device 38 may be installed on the upper part of the side wall W3 or on the ceiling CL, and can be used as is even after renovation.

[0123] When a building renovation according to the present invention is carried out on an indoor space IS including a toilet room S3, the first ventilated door device 10A is replaced with a sealed second door device 10B, and a new ventilation structure 1 utilizing the space above the ceiling AS is installed. As shown in Figure 19, an air intake section 35 consisting of a first ventilation grille 40A and a first opening 26 is installed in the ceiling CL of the corridor S1. An air discharge section 25 consisting of a second ventilation grille 40B and a second opening 36 is installed in the ceiling CL of the toilet room S3. A ventilation duct 60 connecting the air intake section 35 and the air discharge section 25 is installed in the space above the ceiling AS.

[0124] The air intake section 35, the air discharge section 25, and the ventilation duct 60 constitute a ventilation structure 1 for circulating air between the corridor S1 and the toilet room S3. Therefore, even if the second door / window device 10B seals the opening 5, when the exhaust device 38 in the toilet room S3 is activated, the exhaust operation causes air flowing from the living room into the corridor S1 to flow into the ventilation duct 60 through the air intake section 35, as shown by the dashed arrow in Figure 19, and then flow through the ventilation duct 60 to the air discharge section. 25 After flowing out into toilet room S3, it is exhausted from exhaust device 38.

[0125] In embodiments 1 to 3 described above, the door frame 11 of the existing first door device 10A is retained and used as the door frame 11 of the second door device 10B during the door replacement process, but this is not limited to this. The entire door frame 11 may also be replaced during the door replacement process. That is, the door frame 11 forming the first door device 10A may be replaced with the door frame 11 forming the second door device 10B.

[0126] In embodiments 1 to 3 described above, the first joinery device 10A is exemplified as a joinery device 10 in which an undercut is provided on the lower side of the door body 15, but it is not limited to this. The first joinery device 10A may be any other joinery device having a louver or ventilation window, as long as it is configured to form a gap for air to circulate between the corridor S1 and the bedroom S2.

[0127] In embodiments 1 to 3 described above, the second door / window device 10B was assumed to be a single-leaf semi-airtight door, but it is not limited to this. The second door / window device 10B may be an airtight door, or it may be any other door / window device such as a sliding door or a suspended door, as long as it is configured to seal the opening 5 when the door / window is closed.

[0128] In embodiments 1 to 3 described above, the multiple ventilation holes 48 in the ventilation section 47 of the ventilation grille 40 are arranged in a matrix and each is formed in a rectangular shape, but this is not limited to this. Each ventilation hole 48 may be formed in a shape other than rectangular, such as circular or oval. For example, the multiple ventilation holes 48 may each be formed in a slit shape and arranged to extend parallel to each other with a gap between them. In this case, the ventilation section 47 may be composed of an angle-adjustable louver or a fixed louver. Furthermore, any ventilation cover can be used instead of the ventilation grille 40 as long as it is capable of allowing air to circulate.

[0129] In embodiments 1 to 3 described above, the case in which airtight waterproof tape is used as the first cover member 71 and the second cover member 72 was given as an example, but the invention is not limited to this. For example, the first cover member 71 may be a ring-shaped object made of elastomer or resin, having recesses formed around its entire circumference that open radially outward so as to be able to wrap around the inner peripheral edge of the first opening 26 of the first ceiling material 20. The same applies to the second cover member 72.

[0130] Although preferred embodiments of the present invention have been described above, the technical scope of the present invention is not limited to the scope described in each of the above embodiments. It will be understood by those skilled in the art that the above embodiments are illustrative, and that various further modifications are possible in combinations of their components and processing processes, and that such modifications also fall within the scope of the present invention.

[0131] Furthermore, the designations "First," "Second," etc., in the specification and claims are used to distinguish between the terms to which these designations are attached, and do not limit the number or order of such terms. Also, the "~" designation in numerical ranges mentioned above means a range that includes the numbers before and after it. In other words, if X and Y are used as substitutes for numbers, then "X~Y" indicates a range of "greater than or equal to X and less than or equal to Y." [Industrial applicability]

[0132] As described above, the present invention is useful for a building renovation method that achieves both sound insulation and ventilation between two adjacent spaces separated by a partition wall in an indoor space. [Explanation of Symbols]

[0133] 5 Openings 10A First Joinery Device 10B Second Joinery Device 13. Ventilation openings (gaps) 20. First ceiling material 26. First opening 30 Second ceiling material 36. Second opening 60 ventilation duct 61 Sound-absorbing duct 61a First end (one end) 61b Second end (other end) 62 Sound-absorbing material 71 First cover member 72 Second cover member AS ceiling space CL ceiling IS indoor space S1 Corridor (First Use Space) S2 bedroom (second usage space) W1 Partition wall

Claims

1. The system comprises a partition wall separating a first and second adjacent indoor space, a first joinery device capable of opening and closing an opening in the partition wall, a first ceiling material forming the ceiling of the first space, and a second ceiling material forming the ceiling of the second space. The space above the ceiling extends from above the first ceiling material to above the second ceiling material. A building renovation method in which the first building fixture is configured to form a gap that allows air to circulate between the first usable space and the second usable space, A first step involves removing the first joinery device and replacing it with a second joinery device configured to seal the opening in a closed state, A second step involves forming a first opening in the first ceiling material and a second opening in the second ceiling material, The third step includes installing a ventilation duct in the ceiling space, which connects the first opening and the second opening and allows air to circulate between the first and second usable spaces, using a sound-absorbing duct that includes sound-absorbing material. In the second step described above, The first opening is formed with an inner diameter that is larger than the outer diameter of one end of the sound-absorbing duct and smaller than the outer diameter of the sound-absorbing duct in the middle in the longitudinal direction. The second opening is formed with an inner diameter that is larger than the diameter of the other end of the sound-absorbing duct and smaller than the diameter in the middle of the sound-absorbing duct in the longitudinal direction. In the third step described above, The sound-absorbing duct is positioned so that one end of it is extended from the ceiling space through the first opening into the first usable space, and a component of the first ventilation grille is attached to one end of the sound-absorbing duct. The portion of the sound-absorbing duct extending from the first opening is then placed into the ceiling space, and the first ventilation grille is provided on the lower surface of the first ceiling material so as to cover the gap between one end of the sound-absorbing duct and the periphery of the first opening. The sound-absorbing duct is positioned so that the portion including the other end is extended from the ceiling space through the second opening into the second usable space, the other end of the sound-absorbing duct is attached to a component of the second ventilation grille, the portion of the sound-absorbing duct protruding from the second opening is then placed back into the ceiling space, and the second ventilation grille is installed on the lower surface of the second ceiling material so as to cover the gap between the other end of the sound-absorbing duct and the periphery of the second opening. A building renovation method characterized by the following features.

2. In the building renovation method described in claim 1, In the third step described above, a flexible sound-absorbing duct is used as the sound-absorbing duct. A building renovation method characterized by the following features.

3. In the building renovation method described in claim 1, The effective opening area of ​​the aforementioned ventilation duct is 100 cm². ２ That's all. The second joinery device has sound insulation performance that reduces the sound pressure level by 20 dB or more at a frequency of 500 Hz. After the renovation, a sound insulation effect is obtained that reduces the sound pressure level between the first and second usage spaces by 20 dB or more at a frequency of 500 Hz. A building renovation method characterized by the following features.

4. In the building renovation method described in claim 1, In the third step, the sound-absorbing duct is inserted into the ceiling space through the first opening, and while maintaining the state in which one end of the sound-absorbing duct is brought out from the ceiling space through the first opening into the first usable space, the other end of the sound-absorbing duct is pulled out from the second opening into the second usable space. A building renovation method characterized by the following features.

5. In the building renovation method described in claim 1, The fourth step includes attaching a first cover member to the inner periphery of the first opening of the first ceiling material, In the third step, the sound-absorbing duct is inserted into the first opening with the first cover member attached to its inner periphery. A building renovation method characterized by the following features.

6. In the building renovation method described in claim 5, In the fourth step, the first cover member is attached to the inner periphery of the first opening of the first ceiling material in an annular manner such that its inner diameter is larger than the outer diameter of one end of the sound-absorbing duct. A building renovation method characterized by the following features.

7. In the building renovation method described in claim 5, In the fourth step, the second cover member is attached to the inner periphery of the second opening of the second ceiling material. In the third step, the sound-absorbing duct is inserted into the second opening with the second cover member attached to its inner periphery. A building renovation method characterized by the following features.

8. In the building renovation method described in claim 7, In the fourth step described above, The first cover member is attached to the inner periphery of the first opening of the first ceiling material in an annular manner such that its inner diameter is larger than the outer diameter of one end of the sound-absorbing duct. The second cover member is attached to the inner periphery of the second opening of the second ceiling material in an annular manner such that its inner diameter is larger than the outer diameter of the other end of the sound-absorbing duct. A building renovation method characterized by the following features.

9. In the building renovation method according to any one of claims 1 to 8, In the third step described above, the entire ventilation duct is formed by the sound-absorbing duct. A building renovation method characterized by the following features.

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