Sustainable Building Envelopes: Designing the Outer Skin of the Integrated Double Envelope

Abstract

The great 18th century French philosopher, Voltaire said "Men Argue, Nature Acts". Since 1970s, when global warming and climate change phenomena were identified to be impacting the Earth, almost three decades have been spent conducting scientific debates and talks. The general population at large is still ignorant towards implementing prevention strategies due to trivial reasons like expensive installation and maintenance. Meanwhile, the Earth's atmosphere is quickly reaching towards a point-of-noreturn. A predicted increase in global temperature by even 8°C may not affect the comfort with which humans can exist. The problem lies deeper, global warming would trigger extreme catastrophic events that would change the world as we know it. The common impacts discussed range from extinction of wildlife and climate change to decrease in habitable land and threat to human existence. The architectural profession can actively contribute by providing sustainable design innovations. The prevailing conditions demand all buildings- new and existing, to have low energy consumption. However, it is impossible to re- construct all existing buildings, yet possible to renovate their exteriors such that they perform better. This paper researches the integrated double skin envelope as an appropriate sustainable solution, and its impact if implemented on existing structures. The thesis begins with exploring the relation between a sustainable envelope design, especially the twin skin system, and global warming. The literature section investigates the various classifications and designs of advanced building external skins that can be added onto existing envelopes. To understand the importance given to designing sustainable envelopes in actual practice, the literature investigates various Green building rating systems. The parameters derived from here are further elucidated with design methods. Case-studies from around the world have been presented to understand the performance of integrated double envelope systems. The last section aims to implement design solutions derived from literature and case-study analysis on existing Auckland region buildings. The objective is to demonstrate the actual impact of constructing a second skin over the existing envelope. The result is a model that is not only sustainable but can withstand the test of time and climate change.