國內建築管理單位對於住宅違章增建，已從過往模糊性治理轉向考量現況之積極介入，而非正式都市論雖闡述包容違建住宅之都市治理意義，卻缺乏具體干預之分析。本文以都市永續性修補理論，結合環境可供性分析，建立針對國內違建治理之新分析架構，探討違建比例逼近最高之高雄市，如何策略性導入綠建築設計與立體綠化技術，將違章增建合法化，以兼顧永續發展與住宅宜居性。結合田野調查、個案研究與檔案分析，探究典型之屋頂、陽台與車庫違建，如何透過太陽光電設施、景觀陽台，及綠屋頂露臺之模式接軌都市發展目標與產業需求，分析兼具行為—自然雙重可供性之綠能或綠化設施如何替代或轉化原違建構造之領域性與機能，並發揮環境補償作用。上述分析取徑一方面解析以控制、改善為意向之都市違建治理之具體操作機制，使非正式性可持續化；另一方面透過高雄厝發展經驗，揭示違建之永續治理引發之住宅高價化現象，其潛在社會排除與不均地方發展效應，就此提出政策建議。

To upgrade urban imagery while pursuing post-industrial urban redevelopment, Taiwan municipal governments have geared towards proactive, sustainability-based approaches to governing increasing unlicensed built forms. This study explores the ways in which Kaohsiung City selectively incorporates sustainable architectural strategies as well as vertical greenery in order to transform three major extralegal built forms typically seen on rooftop areas, balconies, and on the grounds into formal parts of the existing and new housing complexes. This sustainability fix allows the city to cope with the dilemma of pursuing economy while keeping the city livable and sustainable. The theoretical framework in this study combines urban sustainability fix and environmental affordance to analyze field data. Research methods include field research, case study, and census data analysis to identify the political-economic context and actual functions of this shifting governance of urban informality. Through the lens of urban sustainability fix, this study explores ways for local states to include urban informality into the cities’ growth plans by transforming or upgrading extralegal built forms. It then shows the social effects of rising property prices caused by these new policy initiatives and suggests examples of further intervention for urban planners and public officials to address the issues of possible social exclusion and uneven geographical development.