An Analysis of Building Exterior Walls Renovation

本研究旨在探討老舊建物外牆劣化的整建更新時機與模式，本研究透過台灣政府（包括：台北市政府、內政部營建署）與民間外牆整修廠商的實地調查及專訪、案例資料分析、專家訪談、相關理論與國內外文獻回顧等研究方式，研擬出老舊建築物外牆劣化專業整修的1.工法、2.制度3.成本等面向。「工法」部分以：（1）場鑄敲除工法、（2）場鑄不敲除工法、（3）預鑄現場組裝工法等定性施作方式來比較其優缺點；「制度」部分以：（1）法令制度（2）申請流程（3）施行計畫等執行現況來進行探討；「成本」部分以：（1）單位造價、（2）施工材料、（3）施工工期等實務操作來量化分析其差異與效益。 本研究共蒐集44件外牆整建案作為研究案例（公有部分：台北市政府補助計畫13件、內政部營建署補助計畫17件；私有部分：自行籌措整建14件），研究內容包括：1.以（1）民眾、（2）廠商、（3）政府等不同觀點，歸納出影響外牆劣化整建更新的限制、誘因與關鍵因素；2.以研究案例區分為（1）建築類型、（2）使用型式（3）施作工法與流程、（4）施工材料、（5）施工金額、（6）施工面積及（7）施工工期等，透過基本統計分析其施工成本（NTD/m2）、施工效率（m2/日）與標準差，並以迴歸方程式與散佈圖分析各式工法於不同工程規模下，成本、工期與工程規模間的變化性、關聯性、適用性及共通特性。 研究結果顯示，本研究彙整出1.外牆整建進行前所需考量的5個主要誘因與6個限制，以及民眾、廠商、政府等不同觀點共16點看法。2.工法方面，經由案例基本統計分析，瞭解（1）敲除式工法施作費用最低，施工效率最慢，且成本與施工效率變化程度大、（2）不敲除工法費用及施工效率則皆居中且變化穩定、（3）預鑄式工法費用最高，施工效率最快且成本與施工效率變化穩定。The study aims to explore the optimal timing and model for Renovation of old building external wall. Through data analysis, literature review, theory review field survey, and expert interview, information analysis of the governments (i.e. Taipei City Government; Construction and Planning Agency Ministry of Interior) and subcontractors for external wall Renovation were made to propose a professional renovation of old building external wall considering the construction method, system and cost: For the construction methods, comparison of (1) Cast-in-place and dismantle method; (2) Cast-in-place method; and (3) Pre-cast field assembly method were made. For the systems, (1) government regulations; (2) application procedure, and(3) execution plan and status were probed into. For the cost, (1) Unit price, (2) Material cost, and(3) Construction duration for quantitative result of difference and benefits were analyzed. The study made 44 case studies (13 Taipei city government subsidy programs, 17 Construction and Planning Agency Ministry of Interior subsidy programs and 14 self founded renovations) on Refurbishment for old building external wall. The objectives of those studies includes: (1) Conclude the concerns for the limitation, incentive and key factor of renovation for building external wall. (2) Make statistic analysis of construction cost (NTD/m2), efficiency （m2/day）and standard deviation according to respective building type, application, construction method, material, cost, area and duration. Discover the variability, relevance and common feature between costs, duration and project size through regression study and Scatter plot analysis of various methods under different project sizes. There are two major results in this research.First, five incentives and six constraints before the renovation of building external wall were gathered, and the 16 views from people, construction companies, and government were concluded. Second, for the construction methods, (1) Cast-in-place and dismantle method for the lowest cost, construction efficiency of the slowest, and the cost and construction efficiency is the degree of change large; (2) Cast-in-place method cost and efficiency of construction is center and the changes are stable; (3) Pre-cast field assembly method for the maximum cost, construction of the fastest, and construction efficiency and cost effectiveness change and stability