Designing an adaptive building envelope for warm-humid climate with bamboo veneer as a hygroscopically active material

Abstract

To address climate responsiveness, most of the envelope strategies experimented by architects so far has incorporated automated high-tech systems, electronic sensors and actuators, increasing our energy consumption. As our climate continues to change concomitant to our reliance on non-renewable energy sources, low-tech passive fagade systems require a more thorough investigation to adapt them for large-scale application. This includes an in-depth focus on sustainable building materials to generate a technologically independent, carbon-neutral building fagade. Materials such as bamboo, due to its hygroscopic nature, undergo constant expansion and contraction with changing levels of atmospheric humidity. From a crafting and construction perspective, this spontaneous dimensional change is seen as an inherent drawback of working with bamboo, with attempts being made to control, or mitigate, the change. But in order to develop a passive system of responsive architecture, it is time we look at the hygroscopic movement intrinsic to bamboo as an opportunity, rather than a challenge, and integrate it within the material performance of architecture itself. This paper looks into bamboo veneer as an adaptive material to help rethink building facades as organic, breathable skins rather than a mechanized barrier between human and nature. The methodology incorporates a series of physical experiments to study the deformation of a bilayer bamboo composite consisting of a bamboo veneer bonded with a clear cellulose film. The film, being non-reactive to climate, amplifies the curving motion of bamboo, along with its return to the initial position. The module was then used to explore different fagade patterns to study the opening and closing mechanism that could potentially generate maximum ventilation. The outcome of the research will consist of a working, demonstrable prototype for a no- tech adaptive fagade pattern that, while undergoing a bio-mechanical response, will perform particular functions including shading and/or ventilation, leading to a truly material-integrated architecture.