Choi center
University of British Columbia

Vancouver, BC, Canada

Building Waste Management: The Choi Building incorporates a comprehensive approach to management of building waste and surface water on site. Graywater is collected in the building and directed to an exterior subsurface graywater recycling area. The graywater recycling trench contains plant material and in turn, microbial plant life known for their capacity to neutralize bacteria in the graywater. The recycled graywater is then used for site irrigation. A subsurface holding tank is incorporated for storage of rainwater collected from the roof area. This water is used for summer irrigation of the site and to ensure that the plant life in the graywater trench is never left dry. This design results in no city service connection for graywater waste from the building and no use of city water for site irrigation. The addition of composting toilets to this system allows this building to be "off grid" for sanitary waste.

 Waste Management: Sanitary waste is eliminated through the use of the composting toilets. Waste from sinks is processed on site through a subsurface gray water recycling system and then used for irrigation. This combination eliminates the sanitary connection for this project. The significant amount of reused materials and products with recycled content in this building (60% of primary wood structure, 100% of exterior brick cladding) address waste management by diverting materials from landfills. In addition, a comprehensive waste management plan was implemented during construction. The site separated and recycled waste materials diverted more than one half of the waste generated on site from the landfill.

 Water Conservation: Significant water savings are realized through a series of features. Composting toilets installed in this project do not require water for flushing. City water is generally only required for the low flow lavatory faucets (spring loaded to further reduce waste) and kitchen sinks. Irrigation of site planting material is provided solely from collected rain water (stored in an 8,000 gallon subsurface cistern) and recycled gray water from the building. Projected water usage is approximately 300 gallons per day.