Issue link: http://digital.canadawide.com/i/607779
DECEMBER 2015 | 27 Green Building Design PHOTOGRAPHY CLIFTON LI/COURTESY RYERSON UNIVERSITY often done to address comfort issues and/or water penetration, improvements to building energy usage was also being realized, according to an RJC study that Rowe points to. "The owner was concerned about moisture. We wanted to evaluate the energy impact of a moisture-focused retrofit," Rowe says. One of the buildings was a hotel built in the 1970s. It included two guest towers, one 44 storeys, the other 13, with a total floor area of 850,000 square feet, exclud- ing parking areas. Guests had reported condensation and water leakage at the sin- gle-glazed window systems and were experiencing issues with thermal comfort, according to the RJC study. Single-glazed slider and fixed windows were replaced with a double-glazed fixed system, concrete cladding was repaired and building envelope sealants were replaced. One of the results of this project was a reduction in natural gas consump- tion. "In general, heating and cooling energy reductions were observed in the range of 10 to 20 per cent," according to RJC. Although the payback for envelope retrofits is long compared to that for replac- ing a boiler, Rowe expects more envelope retrofits are coming. He says that energy prices are likely to climb, there could be carbon tax breaks, and, with more retrofits, "There will be more opportunity to compare technologies with savings," says Rowe. A recent project for Zeidler Partnership Architects had to balance the owner's requirement for lots of glass cladding with thermal performance. It was a new 155,000-square-feet learning centre for students at Ryerson University. "Three walls are glass, triple glazed and high performance, and the north wall is concrete and about R-30," says Mike Smith, a senior associate at Zeidler. The roof is more than 50 per cent green and filters rainwater for bathrooms and provides irrigation for other green areas. The project is aiming for LEED Silver. "The high-efficiency curtain wall includes a baked-on frit coating. About 50 per cent of the glass is covered by frit. The fritted area is thermally reflected and also reduces glare in the interior, as well as cooling demand," Smith says. A The Student Learning Centre at Ryerson University.