台灣長期以來，居住者以自行增建方式改變了原有住宅規劃與建築設計，以滿足其對生活定住的想法與需求，住宅空間增建雖是現行建築法制外的脫序行為，不可諱言，卻已是一種眾所周知的建築現象。為了清楚掌握住宅增建的情形，本論文以住宅為研究對象，調查台灣本島各縣市住宅空間增建率與增建原因及其營建形式，並以數據化方式具體呈現台灣住宅空間的增建現象。研究方法以問卷調查法、分析方式進行，研究結果發現：1.台灣本島住宅增建率高達65.9％；2居住者之居住地與相關屬性高低並不影響其增建率；3.居住者之住宅在可自主運用的前提下有較高的增建率；4.增建空間的構成特性為營建成一層樓的鐵皮屋居多；5.增建空間機能多作為曬衣間、儲藏室與雨庇空間之用；6.居住者普遍對住宅增建後觀感持正面評價多過於負面評價。以上研究結果與研究相關數據將有助於理解長久以來住宅增建行為的生成原因與空間形式，並提供其他相關學者作為後續研究參考依據。

For a long time, Taiwan residents extended housing spaces in order to suffice their living demands and provide an ideal living space which they imaged. For understanding the state of housing space extending phenomenon in Taiwan, the task of this study is investigating the formats and reasons of housing space extending by the questionnaire and analysis. The results of this study indicated: 1. The rate of housing space extending in Taiwan is 65.9%. 2. There is no significant relation between location characters and housing space extending. 3. Private properties have higher rate of housing space extending. 4. Most extended housing spaces were made by metal. 5. The main functions of the extended housing spaces are balcony for clothe sun-drying, storeroom or rainproof. 6. Most residents have the positive evaluation of the appearance of extended housing spaces. The results above not only can help us to understand the phenomenon of housing space extending, but also can provide the references for other related researchers to do the deep studies in the future.