單元(yuan)(yuan)式幕(mu)墻(qiang)是再工廠(chang)加工程度(du)最高的(de)一(yi)種類型幕(mu)墻(qiang)。在工廠(chang)不(bu)僅要(yao)加工豎框(kuang)、橫框(kuang)等(deng)元(yuan)(yuan)件(jian)(jian)，還要(yao)用這些元(yuan)(yuan)件(jian)(jian)拼裝成元(yuan)(yuan)件(jian)(jian)組(zu)(zu)(zu)(zu)(zu)件(jian)(jian)框(kuang)，并將幕(mu)墻(qiang)面板（玻璃(li)、鋁板、花崗石等(deng)）安(an)裝在單元(yuan)(yuan)組(zu)(zu)(zu)(zu)(zu)件(jian)(jian)框(kuang)的(de)相應位置上，形(xing)成單元(yuan)(yuan)組(zu)(zu)(zu)(zu)(zu)件(jian)(jian)。就一(yi)個單元(yuan)(yuan)組(zu)(zu)(zu)(zu)(zu)件(jian)(jian)來說，它已具備了(le)這個單元(yuan)(yuan)的(de)全(quan)部幕(mu)墻(qiang)功能和構造要(yao)求。單元(yuan)(yuan)組(zu)(zu)(zu)(zu)(zu)件(jian)(jian)的(de)高度(du)要(yao)等(deng)于或大(da)(da)于一(yi)個樓層，以便運往工地后直接固定(ding)在主體(ti)結(jie)構上。每個單元(yuan)(yuan)組(zu)(zu)(zu)(zu)(zu)件(jian)(jian)上、下框(kuang)（左、右框(kuang)）對插形(xing)成組(zu)(zu)(zu)(zu)(zu)合(he)桿，完成單元(yuan)(yuan)組(zu)(zu)(zu)(zu)(zu)件(jian)(jian)間接縫，最終形(xing)成整幅幕(mu)墻(qiang)。單元(yuan)(yuan)式幕(mu)墻(qiang)的(de)主要(yao)工作量是在工廠(chang)完成的(de)，這樣它可(ke)以進行工業(ye)化生產，大(da)(da)大(da)(da)提(ti)高勞動生產率和產品質量，這就決定(ding)了(le)單元(yuan)(yuan)式幕(mu)墻(qiang)具有一(yi)下特點：   
   （1） 單元式幕(mu)墻(qiang)(qiang)(qiang)(qiang)最大特點(dian)是工(gong)地(di)工(gong)期(qi)短(duan)，它包(bao)含(han)兩重意義上的(de)工(gong)期(qi)短(duan)。其一(yi)，因(yin)為(wei)(wei)(wei)它大部(bu)分(fen)工(gong)作(zuo)量(liang)是在工(gong)廠完(wan)成(cheng)的(de)，運(yun)往公司后僅為(wei)(wei)(wei)吊(diao)(diao)裝就位(wei)、固(gu)定的(de)工(gong)作(zuo)量(liang)，這(zhe)部(bu)分(fen)工(gong)作(zuo)量(liang)占全部(bu)幕(mu)墻(qiang)(qiang)(qiang)(qiang)工(gong)作(zuo)量(liang)的(de)份額很小。根據(ju)統計分(fen)析這(zhe)部(bu)分(fen)工(gong)作(zuo)量(liang)平均實(shi)際使(shi)用時間約為(wei)(wei)(wei)4min/m2，例(li)(li)如(ru)一(yi)個(ge)平面為(wei)(wei)(wei)50m*50m、層(ceng)(ceng)高(gao)為(wei)(wei)(wei)4m的(de)樓層(ceng)(ceng)，墻(qiang)(qiang)(qiang)(qiang)面積約為(wei)(wei)(wei)800m2，工(gong)地(di)工(gong)作(zuo)量(liang)為(wei)(wei)(wei)3200min（53.33h），即(ji)不到2天半即(ji)可(ke)完(wan)成(cheng)一(yi)個(ge)樓層(ceng)(ceng)；其二，幕(mu)墻(qiang)(qiang)(qiang)(qiang)吊(diao)(diao)裝可(ke)以和土建同步進行，使(shi)總工(gong)期(qi)縮(suo)短(duan)，例(li)(li)如(ru)上海金茂大廈（88層(ceng)(ceng)），當主(zhu)體(ti)結(jie)構(gou)(gou)完(wan)成(cheng)18層(ceng)(ceng)時，可(ke)是吊(diao)(diao)裝幕(mu)墻(qiang)(qiang)(qiang)(qiang)，1997年10月主(zhu)體(ti)結(jie)構(gou)(gou)封頂時，幕(mu)墻(qiang)(qiang)(qiang)(qiang)吊(diao)(diao)裝完(wan)70層(ceng)(ceng)，1998年4月（主(zhu)體(ti)結(jie)構(gou)(gou)封頂后6個(ge)月）完(wan)成(cheng)全部(bu)102700m2幕(mu)墻(qiang)(qiang)(qiang)(qiang)吊(diao)(diao)裝彌合（主(zhu)體(ti)結(jie)構(gou)(gou)完(wan)成(cheng)70層(ceng)(ceng)時，幕(mu)墻(qiang)(qiang)(qiang)(qiang)吊(diao)(diao)裝到50層(ceng)(ceng)，內部(bu)裝修開(kai)始，1998年8月底(di)全部(bu)竣工(gong)，交付使(shi)用單位(wei)）。   
    但工(gong)(gong)地工(gong)(gong)期短不會自然實現，要(yao)(yao)靠(kao)人認識單(dan)(dan)(dan)元(yuan)(yuan)式(shi)(shi)幕(mu)墻的(de)(de)(de)(de)特點，對施(shi)工(gong)(gong)組(zu)織作科(ke)學、合理的(de)(de)(de)(de)安排才能(neng)實現，如果部 掌握單(dan)(dan)(dan)元(yuan)(yuan)式(shi)(shi)幕(mu)墻的(de)(de)(de)(de)安裝(zhuang)規(gui)律，可能(neng)適得其反。單(dan)(dan)(dan)元(yuan)(yuan)式(shi)(shi)幕(mu)墻單(dan)(dan)(dan)元(yuan)(yuan)組(zu)件(jian)間(jian)靠(kao)對插完成接縫，因此它(ta)的(de)(de)(de)(de)安裝(zhuang)順序要(yao)(yao)求非(fei)常嚴格(ge)，即每一層一塊(kuai)接一塊(kuai)對插，安裝(zhuang)完一層再安裝(zhuang)上一層，中間(jian)不能(neng)空缺，這(zhe)樣就要(yao)(yao)求施(shi)工(gong)(gong)機(ji)具(ju)（塔(ta)吊、施(shi)工(gong)(gong)電梯(ti)）不能(neng)任意布(bu)(bu)(bu)置(zhi)，只(zhi)能(neng)布(bu)(bu)(bu)置(zhi)在單(dan)(dan)(dan)元(yuan)(yuan)式(shi)(shi)幕(mu)墻的(de)(de)(de)(de)收口部位(wei)。因此采用單(dan)(dan)(dan)元(yuan)(yuan)式(shi)(shi)幕(mu)墻的(de)(de)(de)(de)建(jian)筑的(de)(de)(de)(de)總承包(bao)單(dan)(dan)(dan)位(wei)要(yao)(yao)按(an)這(zhe)一要(yao)(yao)求來進(jin)行整個工(gong)(gong)程的(de)(de)(de)(de)總施(shi)工(gong)(gong)組(zu)織設計，特別是施(shi)工(gong)(gong)總平面圖設計，即施(shi)工(gong)(gong)機(ji)具(ju)（塔(ta)吊、施(shi)工(gong)(gong)電梯(ti)等）要(yao)(yao)按(an)照單(dan)(dan)(dan)元(yuan)(yuan)式(shi)(shi)幕(mu)墻的(de)(de)(de)(de)組(zu)裝(zhuang)規(gui)律來進(jin)行布(bu)(bu)(bu)置(zhi)，這(zhe)是實現工(gong)(gong)地工(gong)(gong)期短的(de)(de)(de)(de)關鍵(jian)。   
   （2）單元式(shi)幕墻(qiang)為建(jian)筑師發揮想(xiang)象力提供了廣(guang)闊(kuo)的(de)天地，由于(yu)在(zai)工廠(chang)組(zu)(zu)裝，可(ke)以用各(ge)種構圖來組(zu)(zu)合，拼裝成單元組(zu)(zu)件，運往工地吊裝就(jiu)位，而構件式(shi)幕墻(qiang)由于(yu)受在(zai)工地安裝條件的(de)限制，一般(ban)只(zhi)能采(cai)(cai)用簡(jian)單平面形式(shi)組(zu)(zu)合。這樣就(jiu)可(ke)以設計出各(ge)種不同風格(ge)的(de)異(yi)形幕墻(qiang)，使采(cai)(cai)用幕墻(qiang)的(de)建(jian)筑物發揮最佳(jia)藝(yi)術(shu)效果(guo)。   
   （3）單(dan)元(yuan)式(shi)(shi)幕(mu)(mu)(mu)墻(qiang)(qiang)(qiang)(qiang)融各(ge)種幕(mu)(mu)(mu)墻(qiang)(qiang)(qiang)(qiang)技術于(yu)一(yi)體（即可采(cai)(cai)用(yong)(yong)各(ge)種不同的(de)(de)金屬(shu)桿件(jian)，各(ge)種不同材質的(de)(de)面(mian)(mian)板(ban)(ban)，用(yong)(yong)各(ge)種方(fang)法(fa)固定面(mian)(mian)板(ban)(ban)）。單(dan)元(yuan)式(shi)(shi)幕(mu)(mu)(mu)墻(qiang)(qiang)(qiang)(qiang)由(you)于(yu)采(cai)(cai)用(yong)(yong)對插接縫(feng)，使幕(mu)(mu)(mu)墻(qiang)(qiang)(qiang)(qiang)對外界因素(su)的(de)(de)變形適應能(neng)力更好；為采(cai)(cai)用(yong)(yong)雨屏等壓原理進行構造設(she)計提供了最(zui)佳場合(he)，從而為提高(gao)(gao)整幅幕(mu)(mu)(mu)墻(qiang)(qiang)(qiang)(qiang)的(de)(de)水(shui)密(mi)(mi)(mi)性(xing)和氣密(mi)(mi)(mi)性(xing)構造了條件(jian)；單(dan)元(yuan)式(shi)(shi)幕(mu)(mu)(mu)墻(qiang)(qiang)(qiang)(qiang)的(de)(de)立面(mian)(mian)布置方(fang)式(shi)(shi)更靈活，為采(cai)(cai)用(yong)(yong)更合(he)理的(de)(de)桿件(jian)計算簡圖提供了條件(jian)，從而使桿件(jian)（豎框）用(yong)(yong)料更經濟；單(dan)元(yuan)式(shi)(shi)幕(mu)(mu)(mu)墻(qiang)(qiang)(qiang)(qiang)由(you)于(yu)在工廠組件(jian)，單(dan)元(yuan)組件(jian)本身的(de)(de)質量控(kong)制比(bi)工地優越(yue)。必(bi)(bi)須指(zhi)出這幾年國內已(yi)安(an)裝(zhuang)(zhuang)的(de)(de)幾個大型超高(gao)(gao)層建筑(zhu)(zhu)的(de)(de)單(dan)元(yuan)式(shi)(shi)幕(mu)(mu)(mu)墻(qiang)(qiang)(qiang)(qiang)接縫(feng)處理采(cai)(cai)用(yong)(yong)的(de)(de)是(shi)國外20實際(ji)七八十(shi)年代(dai)開(kai)發的(de)(de)型材，其水(shui)密(mi)(mi)(mi)性(xing)能(neng)不高(gao)(gao)已(yi)成其通病，縱觀這些建筑(zhu)(zhu)的(de)(de)單(dan)元(yuan)式(shi)(shi)幕(mu)(mu)(mu)墻(qiang)(qiang)(qiang)(qiang)三性(xing)測試報告，其水(shui)密(mi)(mi)(mi)性(xing)很(hen)少有達到1000Pa的(de)(de)，最(zui)低的(de)(de)僅(jin)為300Pa（上海市(shi)規定>＝1600Pa）的(de)(de)要求，同時(shi)這些已(yi)安(an)裝(zhuang)(zhuang)的(de)(de)單(dan)元(yuan)式(shi)(shi)幕(mu)(mu)(mu)墻(qiang)(qiang)(qiang)(qiang)更換(huan)面(mian)(mian)板(ban)(ban)很(hen)困(kun)難，安(an)裝(zhuang)(zhuang)過程(cheng)必(bi)(bi)須一(yi)一(yi)對插，因此(ci)開(kai)發高(gao)(gao)性(xing)能(neng)的(de)(de)單(dan)元(yuan)式(shi)(shi)幕(mu)(mu)(mu)墻(qiang)(qiang)(qiang)(qiang)的(de)(de)任務還很(hen)艱巨。