近年來全球暖化已經成為國際關注的焦點，因此建築外層如何降低能耗及隔絕戶外環境因子，成為重要的議題。如果可以從建築外層先做好構造與材料的選擇，不僅可以有效的降低建築物外殼耗能量ENVLOAD（Envelope Load(kWh/(㎡yr))，以下簡稱（ENVLOAD），還能對節能減碳有很大的貢獻。
透過文獻回顧了解建築物外殼耗能量（ENVLOAD）是我國重要建築物節能指標之一，並且運用在政府訂定「建築物節約能源設計技術規範」之中，由ENVLOAD指標之計算式可發現影響此數值高低的變數相當多。本研究主旨在於探討ENVLOAD算式中哪些與外層相關的變數是影響ENVLOAD值的關鍵因素。透過所蒐集到國內辦公建築案例，分析精算法和簡算法中與建築外層相關的變數，可以得知：開口面積(Ai)、熱傳導率(Ui)、玻璃日射透過率(ηi)、遮陽係數(ki)為建築外層主要影響ENVLOAD的因素。並運用統計學進行相關分析與迴歸分析並將結果圖表化呈現與說明，求出開口部各方位影響ENVLOAD的最主要因子，反饋了解建築外層使用的構造與材料，進而說明在開口部使用何種構造與材料能使ENVLOAD有效降低，以利做為建築外層設計的參考依據。
In recent years, global warming has become the focus of international attention. How to design buildings that require less energy consumption and that effectively insulate external environmental factors has also become an important topic of discussion. Selecting appropriate structures and materials for building exteriors can not only reduce the envelope energy load (ENVLOAD) but also contribute to significant carbon footprint reduction.
Through literature review, it became apparent that ENVLOAD is one of the fundamental energy consumption indices for buildings in Taiwan. According to the Design and Technical Directions for Energy Saving of Buildings promulgated by the government, there are a variety of factors that can affect ENVLOAD estimation. Therefore, the purpose of the present study is to explore the underlying factors of ENVLOAD estimation and determine which of the exterior-related factors contribute more significantly to the overall ENVLOAD. Through case studies of domestic office buildings, the author analyzed the relevant building exterior factors using the standard as well as the simplified method and identified the following key factors of ENVLOAD: areas of openings (Ai), thermal conductivity (Ui), shine-through rates of glass materials (ηi), and shading coefficients (ki). After running a multiple regression analysis, the author presents the statistical results in figures and tables in order to clearly identify and explain the key factors of ENVLOAD in every aspect of architectural openings. These factors will, in turn, inform the selection of suitable structures and materials for building exteriors that lower the overall ENVLOAD. It is the author’s wish that the findings of the present study can serve as a reference for future architectural designs of building exteriors.
