Issue link: http://digital.canadawide.com/i/147234
NetZero Hero Code changes, technological advancements and increasing demand are boosting the energy efficiency of the building envelope A A project of Habitat for Humanity (HFH) that featured by Godfrey Budd in a previous issue of Award (April 2012) may signal that the widespread application of low-energy consumption and NetZero building concepts could be just around the corner. Along with HFH, Lafarge Canada Inc. and Stantec Inc. were primary partners in the construction of the NetZero duplex in Edmonton, which was finally completed last winter. "Energy bills will be greatly reduced, targeting zero on an annual basis as the ultimate achievement in the case of this project," according to a submission to the Precast/Prestressed Concrete Institute (PCI) in May from Kassian Dyck & Associates on behalf of the project team. In fact, the project made such an impact that it is now being considered for a sustainability award from PCI. This project demonstrates that the energy-efficient design of a building starts with the envelope, and clearly, more than a few designers and other consulting experts see concrete's potential in this area. When it comes to concrete, its intrinsic characteristics could ensure its use in many future low-energy consumption and NetZero projects. "The role of precast concrete in NetZero could be huge," says Don Zakariasen, director of marketing at Lafarge. "Its capacity for thermal storage could really help reduce heat and cooling demand at peak times. It's several solutions rolled into one product that meets many needs – for thermal mass, R-value for the outer wall and structural strength." With re-tooling and the use of modern technologies, including robotics applied to the manufacture of precast components, "NetZero becomes feasible on a cost-competitive basis," he says. West LRT project in Calgary. Photos courtesy of Flynn Canada Ltd. Lafarge, which was a key sponsor for the Edmonton NetZero project, will look at the data from the duplex after it has been operating for a year and use it to help develop a business model for bringing low-energy consumption and NetZero building products to market. A June 2013 workshop in Toronto, hosted by Rethink Sustainability Initiatives, provided Zakariasen, who was a featured speaker, an opportunity to tell an audience of experts about the NetZero duplex. "The discussion there showed that collaboration between partners, stakeholders, engineers, suppliers and manufacturers can really bring things forward," he says. Besides energy performance, other qualities associated with precast envelopes include rain penetration resistance, airtightness and durability. A recent paper from Building Science Corporation, entitled High Performance Precast Concrete Building Enclosures: Rain Control, stated that, "To achieve the best control of rain penetration, precast concrete august 2013 p12-21Envelope.indd 13 /13 13-07-12 2:19 PM