室(shi)(shi)內(nei)空(kong)間是(shi)(shi)由地面(mian)(mian)、墻(qiang)面(mian)(mian)、頂(ding)面(mian)(mian)的(de)圍合(he)限(xian)定(ding)而成，從而確定(ding)了(le)室(shi)(shi)內(nei)空(kong)間的(de)大小(xiao)和形狀(zhuang)。進行室(shi)(shi)內(nei)裝飾的(de)目的(de)是(shi)(shi)創(chuang)造適用、美觀的(de)室(shi)(shi)內(nei)環(huan)境，室(shi)(shi)內(nei)空(kong)間的(de)地面(mian)(mian)和墻(qiang)面(mian)(mian)是(shi)(shi)襯托人(ren)和家(jia)具、陳(chen)設的(de)背景，而頂(ding)面(mian)(mian)的(de)差異使(shi)室(shi)(shi)內(nei)空(kong)間更富有變化。