Water Harvesting: Simulating Rainwater Harvesting for Building Envelope Design

The foundation of this research is to provide awareness to the global issue of freshwater scarcity and how architecture, along with digital design, may assist in confronting the issue. Adaptations for desert environments and from desert biota provide influential parameters for water conservation and efficient use. Existing rainwater catchment systems provide knowledge in basic design parameters which may influence new design strategies. In response to the investigation, the project works towards the design of a building envelope implemented for rainwater harvesting in new and existing structures. The design of the envelope is configured to maximize water capture during the wet season and direct it to several retention cavities located within the envelope for future needs, such as during the dry seasons and droughts. Allocating stored water within the envelope may allow building occupants to directly track their daily and weekly water use and guide them towards efficient water use. The project pushes for water conservation strategies and for a decreased dependence on the water utilities. On-site water harvesting may help alleviate peak water demand affecting many developed and developing cities.
As global potable water, freshwater, resources rapidly dwindle, the envelopes of our built environment may be utilized as a solution to the issue presented. Research of arid environmental conditions was conducted to understand the challenges these locations experience with extreme temperatures and shortage of precipitation. It has been in many of these arid environments that strategies have been developed over six millennia which address the water scarcity issue by capturing rainwater in large cisterns, maximize water retention, reducing water use, and recycling wastewater. The environmental movement of the last century sparked new technologies and design strategies for water efficiency; for example grey water systems, drip irrigation, climate-based irrigation controllers, and water efficient fixtures. Morphological adaptations seen in nature, more specifically from integument functionality in desert flora and fauna adapted for arid conditions, provided much of the influence to establish design parameters for a building envelope system. Form, pattern, and skin material developed much of the functionality for rainwater harvesting; parameters used in designing a building envelope suited for rainwater harvesting. Although the research conducted turned out various parameters of events -- water capturing surfaces, drainage and filtering systems, storage cavities, water reuse systems, and hydronic thermal exchange channels -- the design research focuses on rainwater harvesting. The patterns on the envelope create aesthetic events during rainfall as water flows and is channeled for storage in specified cavities within the envelope. Iterations of studies on form and patterns provided discoveries of failure and successes. Simulation models are used to aid in the development of patterns that most successfully capture and store rainwater. Simulation performance of digital prototypes developed serve as guides for further research towards a holistic water conserving architectural envelope.

Embargo status: Restricted to TTU community only. To view, login with your eRaider (top right). Others may request the author grant access exception by clicking on the PDF link to the left.