JP2004183238A

JP2004183238A - Antiseismic reinforcing extension method for dwelling house and structure extended by the method

Info

Publication number: JP2004183238A
Application number: JP2002348326A
Authority: JP
Inventors: Norifumi Konakawa; 憲史粉川; Minoru Terada; 稔寺田; Ryuji Konakawa; 竜司粉川; Hidetoshi Oyoshi; 英俊大吉; Masao Komori; 正夫小森; Yaeko Kida; 八重子貴田; Yutaka Kamigo; 裕上郷; Itsuo Kishimoto; 逸男岸本; Hiroshi Tsunobe; 寛津野邉; Shozo Takigawa; 昇三瀧川
Original assignee: Miracle Three Corp
Current assignee: Miracle Three Corp
Priority date: 2002-11-29
Filing date: 2002-11-29
Publication date: 2004-07-02
Anticipated expiration: 2022-11-29
Also published as: JP3952397B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antiseismic reinforcing extension method of a dwelling house and a structure capable of widening a habitable space even in the house of which the upward and sideward extension is restricted and simultaneously improving earthquake resistance. <P>SOLUTION: In a dwelling house having an upfloor building area smaller than a downfloor area, a new foundation is formed in the vicinity of the foundation of an existing dwelling house and support members are erected on the new foundation and a new roof positioning above the roof of the existing dwelling house is installed on tops of the support members. Thereafter, the roof including a roof truss of the existing dwelling house is removed. A new floor member is formed in the removed portion to form an attic space between the new floor members and the new roof, and further, the floor of the upfloor of the existing dwelling house is extended toward the support members and new walls are attached to the support members. In this way, a new habitable space is formed in an upfloor and angle braces are formed to connect columns and beams of the frame to a skeleton of the existing dwelling house. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は住宅の耐震補強増築方法及びこの方法により増築された建築物に関し、より詳しくは、横方や上方への増築が制限されている場合でも、既存住宅の居住空間を増やすことができ、同時にその耐震性を向上させることも可能な住宅の耐震補強増築方法及びこの方法により増築された建築物に関する。
【０００２】
【従来の技術】
従来、例えば２階建て住宅を増築しようとする場合、敷地に余裕があれば空いている敷地を利用して増築することが可能であるが、敷地に余裕が無い場合には増築することができなかった。
しかし、近年の建築基準法等の改正や規制緩和などによって、従来は２階建ての建築物しか認可されていない地域等においても、３階建ての建築物の構築が許容されるようになってきており、これによって敷地に余裕が無くても２階建ての建物を３階建てとする増築が可能となった。
【０００３】
しかしながら、従来、例えば２階建ての建築物を３階建ての建築物にするためには、柱や壁、梁等の強度の関係から、２階の上部に、更に新規の３階部分を構築することはできず、先ず既存の２階建ての建築物を全て撤去し、その跡地に３階建ての建築物を構築する他はなかったが、このような従来の方法は、不経済であるばかりでなく、産業廃棄物の増加を引き起こし、また居住者は新規な建築物が完成するまで転居を強いられることとなっていた。
【０００４】
そこで、このような実情に鑑みて、本願発明者は、既存の建築物を活用し、居住者が一時的にせよ転居することなく、そのまま鉛直方向上方に増築が可能な建築方法および建築物を提案している（特許文献１参照。）。
【０００５】
【特許文献１】
特開２０００−２８２６９６号公報
【０００６】
【発明が解決しようとする課題】
上記特許文献１に記載の発明は、技術的には非常に優れた発明であるものの、実際には法的な規制、経済的な制約、生活条件的な制約等によって適用できないケースが多く存在しているのが実情であった。
具体的には、例えば建築協定（建築基準法第６９条）により住民（土地所有者）全員の合意で２階建てまでしか建築できないように設定されている場合や、道路斜線制限（建築基準法第５６条等）により実際上２階建ての高さまでしか建築できない場合等の法的な規制を受ける場合、或いは３階建てに増築するほどの資金がない場合や、３階建てにするほどは居住面積を広げる必要がない場合などがあり、かかる場合には上記発明を適用することができなかった。
従って、敷地に余裕がなく且つ上方への増築もできない場合には増築することができず、従来これを可能とするような技術は全く存在していなかった。
【０００７】
また、上記発明によれば、既存建物の周囲を囲うように新規建物を構築することによって既存建物の寿命を延ばすことができるという効果があるが、新規建物によって囲われた既存建物の部分は古い木造住宅のままであるため耐震性が低く、地震によって倒壊する危険性があった。
【０００８】
本発明はこのような問題点に鑑みてなされたものであって、敷地に余裕がないために横方への増築ができず、しかも法的な規制等のため上方への増築もできない場合であっても適用することができるとともに、同時に耐震性を向上させることをも可能とする住宅の耐震補強増築方法及びこの方法により増築された建築物を提供せんとするものである。
【０００９】
【課題を解決するための手段】
請求項１に係る発明は、上層階の建築面積が下層階の建築面積よりも小さい住宅における耐震補強増築方法であって、既存住宅の基礎の外側又は内側の近傍位置に新規基礎を設けて該新規基礎の上に支持部材を立設し、該支持部材の頂部に既存住宅の屋根の上方に位置する新規屋根を設けた後、既存住宅の小屋組を含む屋根を撤去し、該撤去部位に新たな床部材を設けて前記新規屋根との間に小屋裏空間を形成し、さらに前記支持部材に向けて既存住宅の上層階の床を延設して該支持部材に新たな壁を装着することにより、該上層階に新たな居住空間を形成するとともに、既存住宅の骨組みに対して架構の柱と梁を連結する方杖及び梁同士を連結する火打梁を設けることを特徴とする住宅の耐震補強増築方法に関する。請求項２に係る発明は、前記新規基礎を設ける際に、該新規基礎の一部を貯水用の空洞部を有する地下構造体とし、該地下構造体の上部にエレベーターを設置することを特徴とする請求項１記載の住宅の耐震補強増築方法に関する。
請求項３に係る発明は、前記新規屋根により形成される屋上に平行にラチス梁、トラス梁、帯板梁等の梁を設けることにより、手摺の機能をもった構造体を構築し、該構造体により屋上空間を囲繞することを特徴とする請求項１又は２記載の住宅の耐震補強増築方法に関する。
【００１０】
請求項４に係る発明は、上層階の建築面積が下層階の建築面積よりも小さい住宅を増築して得られる建築物であって、既存住宅の基礎の外側又は内側の近傍位置に設けられた新規基礎の上に支持部材が立設され、該支持部材の頂部に既存住宅の屋根の上方に位置する新規屋根が設けられ、既存住宅の小屋組を含む屋根が撤去された部位に新たな床部材が設けられて前記新規屋根との間に小屋裏空間が形成され、前記支持部材に向けて既存住宅の上層階の床が延設されて該支持部材に新たな壁が装着されることにより該上層階に新たな居住空間が形成されてなるとともに、既存住宅の骨組みに対して架構の柱と梁を連結する方杖及び梁同士を連結する火打梁が設けられてなることを特徴とする建築物に関する。
請求項５に係る発明は、前記新規基礎の一部が貯水用の空洞部を有する地下構造体とされ、該地下構造体の上部にエレベーターが設置されてなることを特徴とする請求項４記載の建築物に関する。
請求項６に係る発明は、前記新規屋根により形成される屋上に手摺の機能をもった構造体が屋上空間を囲繞するように設けられ、該構造体は屋上に平行にラチス梁、トラス梁、帯板梁等の梁を設けることにより形成されてなることを特徴とする請求項４又は５記載の建築物に関する。
【００１１】
【発明の実施の形態】
以下、本発明に係る住宅の耐震補強増築方法及びこの方法により増築された建築物の好適な実施形態について、図面を参照しつつ説明する。
図１乃至図５は本発明に係る方法の施工前の状態を示す図である。
図１（ａ）は外観側面図、（ｂ）は外観正面図であり、図２（ａ）は側面断面図、（ｂ）は正面断面図であり、図３（ａ）は軸組側面図、（ｂ）は軸組正面図であり、図４（ａ）は１階平面図、（ｂ）は２階平面図、（ｃ）は屋根伏図であり、図５（ａ）は２階床組図、（ｂ）は小屋組図である。
【００１２】
本発明は、図示のような上層階の建築面積が下層階の建築面積よりも小さい住宅を適用対象とするものであり、主に木造の２階建ての戸建て住宅を対象とするが、プレハブの２階建て戸建て住宅や、３階建ての戸建て住宅をも対象とするものである。
但し、本明細書においては、本発明の代表的な適用例である木造の２階建ての戸建て住宅についてのみ図面を示して説明を行っている。
【００１３】
図６乃至図１５は本発明に係る方法の施工の手順を順番に示す図であり、以下これらの図に基づいて本発明に係る住宅の耐震補強増築方法について説明する。
尚、図６乃至図９は施工途中の状態を示す図であり、図１０乃至図１６は完成時の状態を示す図、即ち本発明に係る建築物を示す図である。また、図６、図８、図１１は軸組図、図７、図９、図１２は外観図であり、それぞれ（ａ）は側面図、（ｂ）は正面図である。また、図１０（ａ）は２階床梁伏図、（ｂ）は２階上部に増設された空間の床梁伏図であり、図１３（ａ）は側面断面図、（ｂ）は正面断面図であり、図１４（ａ）は１階平面図、（ｂ）は２階平面図であり、図１５（ａ）は２階上部に増設された空間の平面図、（ｂ）は屋上の平面図である。
【００１４】
先ず、図６に示す如く、既存住宅（１）の基礎（２）の外側又は内側の近傍に新たな基礎（３）を設ける。尚、この新規基礎（３）は既存基礎（２）と独立して設けることが好ましいが、場合によっては既存基礎（２）と一体化してもよい。尚、新規基礎（３）は既存基礎（２）の外側に設けることが好ましく、図示例では外側に設けた場合が示されている。
これらの新規基礎（３）のうち、既存住宅（１）の一方側（図６（ｂ）では右側）に設ける新規基礎（３ａ）については、他の新規基礎よりも大きくて重量がある鉄筋コンクリート造の地下構造体とする。
この地下構造体は、既存住宅（１）に沿ってその前後方向又は左右方向（図示例では前後方向）に一体的に連続して形成され、その一部に雨水の貯水槽となる空洞部（４）が設けられる。
【００１５】
この地下構造体（３ａ）は、構造体自体と内部の貯水が地震の際に転倒モーメントで生じる基礎の引き抜き力に対抗する錘として作用するため、構築後の建築物の耐震力を大きく向上させることができるとともに、既存住宅（１）に沿って一体的に連続して形成されることで、建物全体のバランスも非常に安定する。
また、地下構造体（３ａ）の底部を、既存基礎（２）の底部より深い位置とすることによって、下方に位置する部分が、地震によって横揺れするときの建物の地中部分が支持地盤に及ぼす横方向の圧縮応力に対する受動面を提供し、既存住宅の横揺れが軽減されて耐震補強が図られる。
さらに、既存住宅（１）に近接する位置に地下構造体（３ａ）が設置されることにより、建物を支持する地盤の剛性を実質的に高めることができる。そのため、地震発生に伴って生じる地盤の歪みが小さくなり、建物の揺れが小さく抑えられ、実質的に既存住宅の耐震補強が図られる。
【００１６】
地下構造体（３ａ）に形成された貯水槽に溜まった水は、トイレの洗浄水や散水用に使用することができるので、資源を有効に再利用することが可能となる。また、従来、貯水用のタンクは建物の近傍外側に設置するのが通例であったため、建物と敷地境界線との間に余裕がない場合には貯水タンクの設置はできなかったが、本発明によれば地下構造体（３ａ）が基礎を兼ねる構造であることから、建物の内側に位置し、これにより既存住宅周囲の敷地に余裕がない場合でも比較的大容量の貯水を可能とする空間を確保することができる。
【００１７】
次いで、図７に示すように、既存住宅（１）の外壁から突出している軒先や屋根の一部（図中破線円で示す）を切除してから、新規基礎（３）の上に既存住宅（１）の周囲を囲うように支持部材（５）を立設する。既存住宅（１）の周囲を包囲する支持部材（５）は強度の面から重量鉄骨で構築することが好ましいが、軽量鉄骨、集成材、木質パネル、在来木造等により包囲・構築してもよい。
さらに、支持部材（５）同士を鉄骨等からなる梁（６）で連結し、支持部材（５）の頂部に既存住宅（１）の屋根の上方に位置する新規屋根（７）を形成する。尚、図示例では、新規屋根（７）を陸屋根とした場合を示しているが、切妻、寄棟、アール等の他の形状としてもよい。
重量鉄骨で架構する場合、ブレースを設置して万一地震時に既存住宅がもたれかかるような場合に、倒壊を未然に防ぐようにするとよい。尚、ブレースは窓の位置を考慮して設置する。
支持部材（５）の立設時においては、図示の如く、新規基礎（３ａ）の貯水槽（４）上部に立設する支持部材（５）は他の部分の支持部材（５）よりも高く形成し、貯水槽上部にエレベーターを設置できる構造とし、新規基礎（３ａ）がエレベーターピットを兼ねるようにする。
【００１８】
既存住宅（１）の屋根の上方に位置する新規屋根（７）を形成した後、図８に示すように、既存住宅（１）の小屋組を含む屋根（９）を撤去する。このとき、撤去される屋根（９）の上部にベランダ（２１）が設けられている場合には、ベランダ（２１）も合わせて撤去する。さらに、新規基礎（３ａ）の貯水槽（４）上部に存在する既存住宅の骨組みも合わせて撤去し、貯水槽（４）の上部にエレベーターを設置するための空間を確保する。
木造住宅における屋根は重い瓦屋根である場合が多く、建物上層部に重量物があるため、地震や台風等による建物の揺れに対してモーメントが大きくなり、柱の白蟻等の侵食による根腐れ等が重なると倒壊の危険を伴い、また、建物全体の重量が増し、既存の躯体に負担がかかり、強度的に弱いため、地震や台風等で屋根が脱落したり、屋根下地、躯体の破損、建物の崩壊等の被害が発生することもあるが、本発明では既存屋根を撤去することで、建物が軽量化され、地震や台風に対する強度を高めることができる。
【００１９】
そして、既存屋根（９）の屋根を撤去した部位に新たな床部材（１０）を設けることによって新規屋根（７）との間に高さ１，４００ｍｍ以下の小屋裏空間（１１）を形成する（図８参照）。この新たに形成された小屋裏空間（１１）は、ロフト、収納空間、吹き抜け等として使用することができる。
次いで、支持部材（５）に向けて既存住宅（１）の上層階（図示例では２階）の床を延設するとともに、支持部材（５）の外側に新たな壁（１２）を装着することにより、該上層階に新たな居住空間となる空間（１３）を形成する。尚、新たな壁（１２）と既存住宅（１）を隔てる部分の既存壁については、全て撤去してもよいし、一部開口してドア等を設置してもよい。また、新たな居住空間（１３）のうち、既存住宅のベランダ（２１）が設けられていた部分については、面積が拡張された新たなベランダ（２２）（図１３及び図１４参照）として使用することができる。
この新たな壁（１２）の装着によって、既存住宅の部分は既存壁との二重壁構造となり、空気層の存在による断熱性・遮音性が向上し、増築後の建物は省エネルギーで閑静な住宅となり、また意匠性にも優れた住宅となる。尚、新たな壁（１２）は、既存住宅（１）の周囲全体を囲うように装着してもよいが、例えば図１２に示すように既存住宅の１階部分を露出させて装着してもよい。
また、新たな壁（１２）の装着に際して、既存住宅の窓をペアガラスに取り替える場合には入窓に、新たな壁に新設窓を設置する場合には出窓になる。
【００２０】
また、新規屋根（７）の上部、即ち屋上部には、図９に示すように、手摺の機能をもった構造体（８）を新規屋根の外周を囲うように構築する。尚、この構造体（８）の構築は、新たな壁（１２）を装着する前に行う。
この構造体（８）は、屋上と平行に手摺として機能するように、好ましくは１，１００ｍｍ以上の上方に上材（８ａ）が位置するように設けられたラチス梁、トラス梁、帯板梁等の梁から形成される。梁の鉛直材（８ｂ）が１１０ｍｍ以上の空間を形成する場合、安全のために手摺内側には板や布等の面状部材が取り付けられる。
【００２１】
このような構造体（８）は、従来の構造と異なり逆梁構造となり、通常の梁に比べて構造体としての一体的な高さが確保でき、従来の線的な構造から面的な構造となり、平面における２次元的な変形に対して強度を確保することが可能となるので、耐震性に優れた建築物が得られる。
また、従来より構造部材を細くすることができるため、内部空間に突出していた梁型を小さくすることが可能となり、内観的に優れたものとなる。
さらに、比較的軽量且つ大スパンの架構を可能とするため、構造体の内側空間における平面設計の自由度が増す。例えば、屋上梁と２階床梁との間に位置する梁を小さくすることができるので、デザイン面、コスト面において制約が少なくなる。
【００２２】
そして、図１０及び図１１に示すように、既存住宅（１）の骨組みに対して架構の柱と梁の接合部を斜めに連結する方杖（１４）及び梁同士を斜めに連結する火打梁（１５）を新たに設ける。尚、図１０において、二点鎖線の×印の部分が既存住宅の部分である。
これら方杖（１４）及び火打梁（１５）によって、既存住宅（１）の骨組み構造体が強固に補強され、地震時の揺れとその増幅を抑制することが可能となり、耐震性が向上して建物の倒壊を防ぐことができる。尚、小屋組み撤去時は、振れ止め又は既存天井を解体せずに方杖を残存軸組みの天井懐内に設置する。
【００２３】
また、２階から小屋裏空間（１１）に続く階段（１９）及び小屋裏空間（１１）から屋上に続く階段（２０）を構築するとともに、新規基礎（３ａ）の貯水槽（４）上部に増築後の住宅の屋上まで達するようにエレベーター（１６）を設置して、既存住宅部分から増築部分への移動を可能とする。
既存住宅（１）が旧耐震設計であった場合、エレベーターの設置が不可能であったが、本発明の方法によれば既存住宅を囲んで新規建物を構築することでホームエレベーター（１６）の設置が可能となる。
【００２４】
最後に、屋上に植栽部（屋上庭園）（１７）と、ソーラーパネル（１８）を備えた発電装置もしくは蓄熱装置を設けることによって増築が完了する。
屋上庭園（１７）を設けることによって、建物の緑被率が大きくなり、ヒートアイランド現象の発生を抑制することができるとともに、ＣＯ_２の増加を抑制して地球温暖化の防止にも貢献することができる。さらに、ソーラーパネル（１８）を備えた発電装置もしくは蓄熱装置を設けることによって、住宅内で消費する電力や熱を補うことができ、エネルギーを節約することが可能となる。
【００２５】
本発明においては、既存建物とこれを包囲するように構築される新規建物の境界を連結せずに縁が切れた状態としてもよいが、エキスパンションジョイントやエネルギー吸収部材で連結することも可能である。
エネルギー吸収部材としては、粘弾性ダンパー、弾塑性ダンパー、オイルダンパー、摩擦ダンパー等を例示することができ、このようなエネルギー吸収部材により既存建物と新規建物を連結することによって、平面二次元方向の変形に対してエネルギー吸収機能が発揮され、耐震性を高めることが可能となる。
【００２６】
以上のように増築された建築物は、施工前の状態を示す図４（ｂ）と施工完了後の状態を示す図１４（ｂ）を比較して明らかなように、増築前の既存住宅に比べて上層階（２階）の居住空間が大きく広がり、さらに図１３及び図１５（ａ）に示すように収納空間等に利用できる小屋裏空間が新たに形成された住宅となり、様々な制約により上方や横方への増築ができない場合でも、住居内の空間を拡大することが可能となり、居住性を高めることができる。
また、本発明の方法は、居住者が居住したままの状態にて増築することが可能であるため、引越しの手間や費用がかからないという大きなメリットもある。
【００２７】
図１６は本発明の適用対象となる既存住宅の例を示しており、（ａ）〜（ｄ）は平面図、（ｅ）〜（ｈ）は側面図である。
（ａ）は上層階の建築面積が下層階の建築面積よりも小さいことによって下層階の上部に存在する空間（以下、外部空間（１９）という）が、上層階の側方１面側のみに形成されている場合、（ｂ）は外部空間（１９）が上層階の側方２面に亘って形成されている場合、（ｃ）は外部空間（１９）が上層階の側方３面に亘って形成されている場合、（ｄ）は外部空間（１９）が上層階の側方４面に亘って形成されている場合をそれぞれ示す。
また、（ｅ）は既存住宅が２階建てであって外部空間（１９）が上層階の側方１面側のみに形成されている場合、（ｆ）は既存住宅が２階建てであって外部空間（１９）が上層階の側方２面に形成されている場合、（ｇ）は既存住宅が３階建てであって外部空間（１９）が上層階（２階と３階）の側方１面側に形成されている場合、（ｈ）は既存住宅が３階建てであって外部空間（１９）が上層階（３階）の１面側に形成されている場合をそれぞれ示す。
既存の戸建て住宅の多くは上記したいずれかの形態を有しているから、本発明は非常に適用範囲が広い利用価値の高い発明であるということができる。
【００２８】
【発明の効果】
以上説明したように、本発明に係る住宅の耐震補強増築方法及びこの方法により増築された建築物によれば、敷地に余裕がないために横方への増築ができず、しかも法的な規制等のため上方への増築もできない場合であっても、増築によって居住空間を増やすことが可能となり、特に既存の戸建て住宅の主流である２階建て住宅の大部分に対して好適に適用することができ、同時に既存住宅の耐震性を大幅に向上させることが可能となり、長期間にわたって安全で快適に居住できる住居を得ることができる。
【図面の簡単な説明】
【図１】本発明に係る方法の施工前の状態を示す図であって、（ａ）は外観側面図、（ｂ）は外観正面図である。
【図２】本発明に係る方法の施工前の状態を示す図であって、（ａ）は側面断面図、（ｂ）は正面断面図である。
【図３】本発明に係る方法の施工前の状態を示す図であって、（ａ）は軸組側面図、（ｂ）は軸組正面図である。
【図４】本発明に係る方法の施工前の状態を示す図であって、（ａ）は１階平面図、（ｂ）は２階平面図、（ｃ）は屋根伏図である。
【図５】本発明に係る方法の施工前の状態を示す図であって、（ａ）は２階床組図、（ｂ）は小屋組図である。
【図６】本発明に係る方法の施工途中の状態を示す図であって、（ａ）は軸組側面図、（ｂ）は軸組正面図である。
【図７】本発明に係る方法の施工途中の状態を示す図であって、（ａ）は外観側面図、（ｂ）は外観正面図である。
【図８】本発明に係る方法の施工途中の状態を示す図であって、（ａ）は軸組側面図、（ｂ）は軸組正面図である。
【図９】本発明に係る方法の施工途中の状態を示す図であって、（ａ）は外観側面図、（ｂ）は外観正面図である。
【図１０】本発明に係る方法の施工完了後の建築物を示す図であって、（ａ）は２階床梁伏図、（ｂ）は２階上部に増設された空間の床梁伏図である。
【図１１】本発明に係る方法の施工完了後の建築物を示す図であって、（ａ）は軸組側面図、（ｂ）は軸組正面図である。
【図１２】本発明に係る方法の施工完了後の建築物を示す図であって、（ａ）は外観側面図、（ｂ）は外観正面図である。
【図１３】本発明に係る方法の施工完了後の建築物を示す図であって、（ａ）は側面断面図、（ｂ）は正面断面図である。
【図１４】本発明に係る方法の施工完了後の建築物を示す図であって、（ａ）は１階平面図、（ｂ）は２階平面図である。
【図１５】本発明に係る方法の施工完了後の建築物を示す図であって、（ａ）は２階上部に増設された空間の平面図、（ｂ）は屋上の平面図である。
【図１６】本発明の適用対象となる既存住宅の例を示す図である。
【符号の説明】
１既存住宅
２既存住宅の基礎
３新規基礎
３ａ新規基礎（地下構造体）
４貯水槽（空洞部）
５支持部材
６梁
７新規屋根
８構造体
８ａ構造体の梁
８ｂ鉛直材
９既存住宅の屋根
１０新たな床部材
１１小屋裏空間
１２新たな壁
１３新たな居住空間
１４方杖
１５火打梁
１６エレベーター
１７植栽部（屋上庭園）
１８ソーラーパネル
１９階段
２０階段
２１既存住宅のベランダ
２２新設のベランダ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a seismic retrofitting extension method of a house and a building added by this method, and more particularly, even if extension to the side or upward is restricted, it is possible to increase the living space of an existing house, At the same time, the present invention relates to a seismic retrofitting extension method for a house capable of improving its seismic resistance and a building extended by this method.
[0002]
[Prior art]
Conventionally, for example, when trying to expand a two-story house, it is possible to expand using a vacant site if there is enough room, but it is possible to expand if there is not enough room. Did not.
However, due to recent amendments to the Building Standards Law and deregulation, construction of three-story buildings has been allowed even in areas where only two-story buildings have been conventionally approved. This has made it possible to add a two-story building to a three-story building, even if there is no room on the site.
[0003]
However, conventionally, for example, in order to convert a two-story building to a three-story building, a new three-story part is constructed on the upper part of the second floor due to the strength of columns, walls, beams, and the like. There was no alternative but to remove all existing two-story buildings first and build a three-story building on the site, but such conventional methods are uneconomical. Not only that, it caused an increase in industrial waste, and residents had to move out until new buildings were completed.
[0004]
In view of such circumstances, the inventor of the present application has utilized an existing building, and has developed a building method and a building that can be expanded vertically upward without occupants temporarily relocating. It has been proposed (see Patent Document 1).
[0005]
[Patent Document 1]
JP 2000-282696 A
[Problems to be solved by the invention]
Although the invention described in Patent Document 1 is a technically excellent invention, there are many cases in which it cannot be applied due to legal regulations, economic constraints, living conditions, and the like. That was the fact.
Specifically, for example, the building agreement (Article 69 of the Building Standards Act) sets all the residents (land owners) to be able to build up to two stories by agreement, (Article 56 etc.) if you are legally restricted to building up to a height of only two stories, if you do not have enough funds to expand to three stories, or if you have three stories, In some cases, it is not necessary to increase the living area, and in such a case, the above invention could not be applied.
Therefore, if there is no room on the site and it is not possible to expand the building upward, the building cannot be expanded, and there has been no technology that makes this possible.
[0007]
Further, according to the above invention, there is an effect that the life of the existing building can be extended by constructing the new building so as to surround the periphery of the existing building, but the portion of the existing building surrounded by the new building is old. Since it was a wooden house, its seismic resistance was low, and there was a risk of collapse due to an earthquake.
[0008]
The present invention has been made in view of such a problem, and in the case where it is impossible to expand the building laterally because there is no room on the site, and it is not possible to expand the building upward due to legal regulations and the like. An object of the present invention is to provide a seismic retrofitting extension method for a house, which can be applied at the same time as improving the seismic resistance at the same time, and a building extended by this method.
[0009]
[Means for Solving the Problems]
The invention according to claim 1 is a seismic retrofit expansion method for a house in which the building area of the upper floor is smaller than the building area of the lower floor, wherein a new foundation is provided at a position near the outside or inside of the foundation of the existing house. A support member is erected on a new foundation, and a new roof located above the roof of the existing house is provided at the top of the support member. A new floor member is provided to form a backstory space between the new roof and the new roof, and an upper floor of an existing house is extended toward the support member, and a new wall is attached to the support member. By this, a new living space is formed on the upper floor, and a stake that connects the columns and beams of the frame to the framework of the existing house and a fire beam that connects the beams are provided. It relates to the method of seismic reinforcement and extension. The invention according to claim 2 is characterized in that, when the new foundation is provided, a part of the new foundation is an underground structure having a cavity for storing water, and an elevator is installed above the underground structure. The present invention relates to a method for adding seismic reinforcement of a house according to claim 1.
The invention according to claim 3 provides a structure having a handrail function by providing beams such as lattice beams, truss beams, and strip beams in parallel on the roof formed by the new roof. The method according to claim 1 or 2, wherein the roof space is surrounded by a body.
[0010]
The invention according to claim 4 is a building obtained by expanding a house in which the building area of the upper floor is smaller than the building area of the lower floor, and is provided near the outside or inside of the foundation of the existing house. A support member is erected on the new foundation, a new roof is provided on the top of the support member above the roof of the existing house, and a new floor is provided at a site where the roof including the hut of the existing house has been removed. A member is provided, a hut space is formed between the new roof and the new roof, a floor of an upper floor of an existing house is extended toward the support member, and a new wall is attached to the support member. A new living space is formed on the upper floor, and a brace for connecting columns and beams of the frame and a fire beam for connecting the beams to the framework of the existing house are provided. Concerning buildings.
The invention according to claim 5 is characterized in that a part of the new foundation is an underground structure having a cavity for storing water, and an elevator is installed above the underground structure. Related to the building.
The invention according to claim 6 is characterized in that a structure having a handrail function is provided on a roof formed by the new roof so as to surround a roof space, and the structure is provided with a lattice beam, a truss beam parallel to the roof. The building according to claim 4 or 5, wherein the building is formed by providing a beam such as a strip beam.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a seismic retrofit extension method for a house according to the present invention and a building extended by the method will be described below with reference to the drawings.
1 to 5 are views showing a state before construction of the method according to the present invention.
1A is an external side view, FIG. 2B is an external front view, FIG. 2A is a side cross-sectional view, FIG. 2B is a front cross-sectional view, and FIG. , (B) is a front view of the frame, FIG. 4 (a) is a plan view of the first floor, (b) is a plan view of the second floor, (c) is a roof plan, and FIG. FIG. 3B is a floor assembly drawing, and FIG.
[0012]
The present invention is applied to a house where the building area of the upper floor as shown is smaller than the building area of the lower floor, and is mainly applied to a wooden two-story detached house. It also covers two-story detached houses and three-story detached houses.
However, in this specification, only a wooden two-story detached house, which is a typical application example of the present invention, is described with reference to drawings.
[0013]
FIGS. 6 to 15 are diagrams sequentially showing the procedure of construction of the method according to the present invention, and the seismic retrofitting extension method of a house according to the present invention will be described based on these drawings.
6 to 9 are views showing a state during construction, and FIGS. 10 to 16 are views showing a state at the time of completion, that is, a view showing a building according to the present invention. FIGS. 6, 8, and 11 are shaft assembly diagrams, FIGS. 7, 9, and 12 are external views, in which (a) is a side view and (b) is a front view. 10 (a) is a floor beam floor plan of the second floor, (b) is a floor beam floor plan of a space added to the upper part of the second floor, FIG. 13 (a) is a side sectional view, and (b) is a front view. 14 (a) is a plan view of the first floor, FIG. 14 (b) is a plan view of the second floor, FIG. 15 (a) is a plan view of a space added to the upper part of the second floor, and FIG. FIG.
[0014]
First, as shown in FIG. 6, a new foundation (3) is provided near the outside or inside of the foundation (2) of the existing house (1). The new foundation (3) is preferably provided independently of the existing foundation (2), but may be integrated with the existing foundation (2) in some cases. It is preferable that the new foundation (3) is provided outside the existing foundation (2). In the illustrated example, the case where the new foundation is provided outside is shown.
Among these new foundations (3), the new foundation (3a) provided on one side (the right side in FIG. 6 (b)) of the existing house (1) has a reinforced concrete structure which is larger and heavier than the other new foundations. Underground structure.
The underground structure is formed integrally and continuously along the existing house (1) in the front-rear direction or the left-right direction (in the illustrated example, the front-rear direction), and a part of the cavity ( 4) is provided.
[0015]
In the underground structure (3a), the structure itself and the internal water storage function as a weight against the pull-out force of the foundation caused by the overturning moment in the event of an earthquake. In addition to being able to be formed integrally and continuously along the existing house (1), the balance of the whole building is very stable.
In addition, by making the bottom of the underground structure (3a) deeper than the bottom of the existing foundation (2), the part located below the underground part of the building when the building rolls due to the earthquake becomes the supporting ground. It provides a passive surface against the compressive stress in the horizontal direction, reduces the roll of existing houses, and provides seismic reinforcement.
Further, by installing the underground structure (3a) at a position close to the existing house (1), the rigidity of the ground supporting the building can be substantially increased. As a result, the distortion of the ground caused by the occurrence of the earthquake is reduced, the shaking of the building is suppressed, and the seismic reinforcement of the existing house is substantially achieved.
[0016]
The water collected in the water storage tank formed in the underground structure (3a) can be used for flushing and watering the toilet, so that resources can be effectively reused. Conventionally, the water storage tank was conventionally installed outside the vicinity of the building. Therefore, if there is no room between the building and the site boundary, the water storage tank cannot be installed. According to the above, since the underground structure (3a) also serves as a foundation, it is located inside the building, thereby enabling a relatively large-capacity water storage even when there is no room at the site around the existing house. Can be secured.
[0017]
Next, as shown in FIG. 7, after cutting off the eaves and a part of the roof (indicated by a broken-line circle in the figure) protruding from the outer wall of the existing house (1), the existing house is placed on the new foundation (3). A support member (5) is erected so as to surround the periphery of (1). The supporting member (5) surrounding the existing house (1) is preferably constructed of heavy steel from the viewpoint of strength. However, even if the supporting member (5) is surrounded and constructed of lightweight steel, glulam, wood panel, conventional wooden structure, or the like. Good.
Further, the support members (5) are connected to each other by a beam (6) made of steel or the like, and a new roof (7) located above the roof of the existing house (1) is formed on the top of the support member (5). In the illustrated example, the case where the new roof (7) is a land roof is shown, but another shape such as a gable, a ridge, or a radius may be used.
If the frame is made of heavy steel, a brace should be installed to prevent the collapse of the existing house in case the existing house leans in the event of an earthquake. The brace is installed in consideration of the position of the window.
When the support member (5) is erected, as shown, the support member (5) erected above the water tank (4) of the new foundation (3a) is higher than the support members (5) of the other parts. The new foundation (3a) also serves as an elevator pit.
[0018]
After forming the new roof (7) located above the roof of the existing house (1), the roof (9) including the hut combination of the existing house (1) is removed as shown in FIG. At this time, if a veranda (21) is provided above the roof (9) to be removed, the veranda (21) is also removed. In addition, the framework of the existing house existing above the water storage tank (4) of the new foundation (3a) will also be removed, and a space for installing an elevator will be secured above the water storage tank (4).
Roofs in wooden houses are often heavy tiled roofs, and because there is a heavy object in the upper layer of the building, the moment increases due to the shaking of the building due to an earthquake or a typhoon, etc. If they overlap, there is a danger of collapse, and the weight of the entire building increases, placing a burden on the existing skeleton and weak in strength, so the roof may fall off due to an earthquake or typhoon, etc. Although damage such as collapse of the building may occur, in the present invention, by removing the existing roof, the building is reduced in weight and the strength against earthquakes and typhoons can be increased.
[0019]
Then, a new floor member (10) is provided at a site where the roof of the existing roof (9) has been removed to form a cabin space (11) having a height of 1,400 mm or less between the new roof (7) and the new roof member (7). (See FIG. 8). The newly formed cabin back space (11) can be used as a loft, a storage space, a stairwell or the like.
Next, the floor of the upper floor (the second floor in the illustrated example) of the existing house (1) is extended toward the support member (5), and a new wall (12) is mounted outside the support member (5). Thus, a space (13) serving as a new living space is formed on the upper floor. It should be noted that the existing wall at a portion separating the new wall (12) and the existing house (1) may be entirely removed, or a part of the wall may be opened and a door or the like may be installed. In addition, in the new living space (13), a portion where the veranda (21) of the existing house was provided is used as a new veranda (22) having an expanded area (see FIGS. 13 and 14). be able to.
By installing this new wall (12), the existing house part becomes a double wall structure with the existing wall, the heat insulation and sound insulation properties are improved due to the presence of the air layer, and the building after expansion is an energy-saving and quiet house It will also be a house with excellent design. The new wall (12) may be installed so as to surround the entire circumference of the existing house (1), but may be installed by exposing the first floor portion of the existing house as shown in FIG. Good.
In addition, when installing a new wall (12), the window of an existing house is replaced with a pair of glass, and the window becomes an entrance window. When a new window is installed on a new wall, the window becomes a bay window.
[0020]
As shown in FIG. 9, a structure (8) having a handrail function is constructed on the upper part of the new roof (7), that is, on the roof so as to surround the outer periphery of the new roof. The construction of the structure (8) is performed before a new wall (12) is mounted.
The structure (8) is provided with a lattice beam, a truss beam, and a strip beam provided so as to function as a handrail in parallel with the roof, and preferably to have the upper member (8a) positioned above 1,100 mm or more. And the like. When the vertical member (8b) of the beam forms a space of 110 mm or more, a planar member such as a plate or cloth is attached inside the handrail for safety.
[0021]
Unlike the conventional structure, such a structure (8) has an inverted beam structure, can secure an integral height as a structure as compared with a normal beam, and has a planar structure instead of a conventional linear structure. Thus, it is possible to secure strength against two-dimensional deformation in a plane, so that a building excellent in earthquake resistance can be obtained.
Further, since the structural member can be made thinner than before, the beam shape projecting into the internal space can be made smaller, and the inner appearance becomes excellent.
Furthermore, since a relatively lightweight and large-span frame is made possible, the degree of freedom in planar design in the space inside the structure increases. For example, the size of the beam located between the roof beam and the second floor beam can be reduced, so that restrictions on design and cost are reduced.
[0022]
Then, as shown in FIGS. 10 and 11, a brace (14) for connecting the joints of the frame columns and beams diagonally to the framework of the existing house (1) and a fire strut for connecting the beams diagonally. (15) is newly provided. In FIG. 10, a portion indicated by a cross in a two-dot chain line is a portion of an existing house.
With the brace (14) and the striking beam (15), the frame structure of the existing house (1) is strongly reinforced, and it is possible to suppress the shaking during the earthquake and its amplification, thereby improving the earthquake resistance. The building can be prevented from collapsing. In addition, when removing the hut assembly, the studs will be installed in the ceiling of the remaining framing without removing the steady rest or dismantling the existing ceiling.
[0023]
In addition, the stairs (19) leading from the second floor to the attic space (11) and the stairs (20) leading from the attic space (11) to the roof are constructed, and at the top of the water tank (4) of the new foundation (3a). An elevator (16) is installed so as to reach the roof of the house after the extension, so that it is possible to move from the existing house to the extension.
When the existing house (1) had the old seismic design, it was impossible to install an elevator. However, according to the method of the present invention, a new building is constructed around the existing house to construct the home elevator (16). Installation becomes possible.
[0024]
Finally, the extension is completed by providing a power plant or a heat storage device having a planting section (roof garden) (17) and a solar panel (18) on the roof.
By providing the roof garden (17), the green coverage of the building increases, the occurrence of the heat island phenomenon can be suppressed, and the increase in CO ₂ can be suppressed to contribute to the prevention of global warming. it can. Further, by providing a power generation device or a heat storage device provided with the solar panel (18), it is possible to supplement the power and heat consumed in the house, and to save energy.
[0025]
In the present invention, the boundary between the existing building and the new building constructed so as to surround it may be cut off without connecting the boundary, but it is also possible to connect with an expansion joint or an energy absorbing member. .
Examples of the energy absorbing member include a viscoelastic damper, an elasto-plastic damper, an oil damper, a friction damper, and the like. By connecting an existing building and a new building with such an energy absorbing member, a two-dimensional plane can be used. An energy absorbing function is exhibited against deformation, and seismic resistance can be improved.
[0026]
As is clear from the comparison between FIG. 4 (b) showing the state before the construction and FIG. 14 (b) showing the state after the completion of the construction, the building added as described above is the same as the existing house before the extension. In comparison, the living space on the upper floor (the second floor) greatly expands, and as shown in FIG. 13 and FIG. 15 (a), a hut back space that can be used as a storage space becomes a newly formed house. Even when it is not possible to extend the building upward or sideways, it is possible to enlarge the space in the house, and it is possible to enhance the livability.
In addition, the method of the present invention has a great advantage in that it is possible to expand the building while the resident is resident, so that the moving time and labor are not required.
[0027]
FIG. 16 shows an example of an existing house to which the present invention is applied. (A) to (d) are plan views, and (e) to (h) are side views.
(A) shows that the upper floor has a smaller building area than the lower floor, so that a space existing above the lower floor (hereinafter referred to as an external space (19)) is located only on one side of the upper floor. In the case where the outer space (19) is formed, the outer space (19) is formed over the two side surfaces of the upper floor, and the outer space (19) is formed in the three side surfaces of the upper floor. (D) shows a case where the external space (19) is formed over four side surfaces of the upper floor, respectively.
(E) is a case where the existing house is a two-story building and the external space (19) is formed only on one side of the upper floor, and (f) is a case where the existing house is a two-story building. When the external space (19) is formed on two sides of the upper floor, (g) shows that the existing house has three floors and the external space (19) is on the upper floor (the second and third floors). (H) shows a case where the existing house has three floors and the external space (19) is formed on one side of the upper floor (third floor), respectively.
Since many existing detached houses have any of the above-described forms, the present invention can be said to be an invention having a very wide range of applications and a high use value.
[0028]
【The invention's effect】
As described above, according to the seismic retrofitting extension method for a house according to the present invention and the building added by this method, the site cannot be expanded laterally because there is no room on the site, and legal regulations Even if it is not possible to expand the building upwards due to factors such as the expansion, it is possible to increase the living space by expanding the building, and it is particularly suitable for most of the two-story houses that are the mainstream of existing detached houses. At the same time, it is possible to greatly improve the seismic resistance of the existing house, and to obtain a house that can be safely and comfortably lived for a long period of time.
[Brief description of the drawings]
FIG. 1 is a diagram showing a state before construction of a method according to the present invention, wherein (a) is an external side view and (b) is an external front view.
FIGS. 2A and 2B are views showing a state before construction of the method according to the present invention, wherein FIG. 2A is a side sectional view and FIG.
FIGS. 3A and 3B are views showing a state before construction of the method according to the present invention, wherein FIG. 3A is a side view of a shaft assembly, and FIG.
FIGS. 4A and 4B are views showing a state before construction of the method according to the present invention, wherein FIG. 4A is a plan view of the first floor, FIG. 4B is a plan view of the second floor, and FIG.
FIGS. 5A and 5B are diagrams showing a state before construction of the method according to the present invention, in which FIG. 5A is a two-story floor assembly diagram, and FIG.
6A and 6B are views showing a state in the middle of construction of the method according to the present invention, wherein FIG. 6A is a side view of a shaft assembly, and FIG.
FIGS. 7A and 7B are views showing a state in the middle of construction of the method according to the present invention, wherein FIG. 7A is an external side view and FIG. 7B is an external front view.
8A and 8B are views showing a state in the middle of construction of the method according to the present invention, wherein FIG. 8A is a side view of a shaft assembly, and FIG.
9A and 9B are views showing a state in the middle of construction of the method according to the present invention, wherein FIG. 9A is an external side view, and FIG. 9B is an external front view.
10A and 10B are diagrams showing a building after the completion of the method according to the present invention, wherein FIG. 10A is a floor-girder floor plan of the second floor, and FIG. 10B is a floor-girder floor of a space added to the upper part of the second floor. FIG.
FIGS. 11A and 11B are views showing a building after the completion of the method according to the present invention, wherein FIG. 11A is a side view of a frame, and FIG. 11B is a front view of the frame.
FIGS. 12A and 12B are diagrams showing a building after the completion of the method according to the present invention, wherein FIG. 12A is an external side view and FIG. 12B is an external front view.
FIG. 13 is a view showing a building after the completion of the method according to the present invention, wherein (a) is a side sectional view and (b) is a front sectional view.
FIGS. 14A and 14B are views showing a building after the completion of the method according to the present invention, wherein FIG. 14A is a plan view of the first floor, and FIG.
FIGS. 15A and 15B are views showing a building after the completion of the method according to the present invention, wherein FIG. 15A is a plan view of a space added to the upper part of the second floor, and FIG.
FIG. 16 is a diagram showing an example of an existing house to which the present invention is applied.
[Explanation of symbols]
1 Existing House 2 Existing House Foundation 3 New Foundation 3a New Foundation (Underground Structure)
4 water storage tank (cavity)
5 Support member 6 Beam 7 New roof 8 Structure 8a Structural beam 8b Vertical member 9 Roof of existing house 10 New floor member 11 Back cabin space 12 New wall 13 New living space 14 Cross beam 15 Fire strut 16 Elevator 17 Planting Department (Roof Garden)
18 Solar panel 19 Stairs 20 Stairs 21 Veranda of existing house 22 New veranda

Claims

A seismic retrofit expansion method for a house in which the building area of an upper floor is smaller than the building area of a lower floor, wherein a new foundation is provided near the outside or inside of a foundation of an existing house, and a supporting member is provided on the new foundation. After standing, providing a new roof located above the roof of the existing house on the top of the support member, removing the roof including the hut of the existing house, providing a new floor member at the removal site, By forming a cabin back space between the new roof and the upper floor of the existing house extending toward the support member and installing a new wall on the support member, a new wall is formed on the upper floor. A method of adding seismic reinforcement to a house, which comprises forming a living space and providing a brace for connecting columns and beams of the frame and a fire beam for connecting the beams to the frame of the existing house.

2. The house according to claim 1, wherein when the new foundation is provided, a part of the new foundation is an underground structure having a cavity for storing water, and an elevator is installed above the underground structure. How to add seismic reinforcement.

By providing beams such as lattice beams, truss beams, and strip beams parallel to the roof formed by the new roof, a structure having a handrail function is constructed, and the roof space is surrounded by the structures. The seismic retrofitting extension method for a house according to claim 1 or 2, wherein:

A building obtained by expanding a house where the building area of the upper floor is smaller than the building area of the lower floor, where the support member is on a new foundation provided near the outside or inside of the foundation of the existing house A new roof is provided upright on the top of the support member and located above the roof of the existing house, and a new floor member is provided at a site where the roof including the hut of the existing house has been removed and the new roof is provided. A space behind the hut is formed, and a floor of the upper floor of the existing house is extended toward the support member, and a new wall is attached to the support member, so that a new living space is provided on the upper floor. A building, characterized by being provided with a brace for connecting columns and beams of a frame to a frame of an existing house and a fire beam for connecting beams to each other.

The building according to claim 4, wherein a part of the new foundation is an underground structure having a cavity for storing water, and an elevator is installed above the underground structure.

A structure having a handrail function is provided on the roof formed by the new roof so as to surround the roof space, and the structure is provided with beams such as lattice beams, truss beams, and strip beams parallel to the roof. The building according to claim 4, wherein the building is formed by: