Issue link: http://digital.canadawide.com/i/1295215
Mt. Boucherie Winery, West Kelowna, B.C. O C T O B E R 2 0 2 0 | 9 Building Envelope P H OTO G R A P H Y BY A M I E B E T H C A I R N S/ CO U RT E SY T R S B U I L D I N G EN V ELO P E Views of the building envelope are changing, and the experts are listening by ROBIN BRUNET Bridge The Gap T he outcome of many progressive initiatives is usually a domino effect, in that once a standard is identified and deemed important to meet, a better standard will eventually be identified as the next goal to achieve, and so on. That is especially true in the seemingly endless journey towards building energy efficiency. Whereas not too long ago initiatives such as LEED were viewed as the standard bearer of construction excellence, the once-niche Zero Carbon structures are rapidly becoming mainstream and spurring developers of other types of buildings to up their game. Hence, aside from an almost fanatical devotion to controlling thermal bridging and providing really good glass and window frames, developers are pay- ing special attention to building envelopes – to the degree that some experts think some popular sys- tems may soon become obsolete. Jeff Ker, senior technical advisor at Engineered Assemblies, says, "With regards to all the elements that go into creating a building envelope, a meth- odology of using products in the best possible way is sorely needed. Materials come with warranties that cover manufacturing defects, but very little atten- tion is paid to how to attain the longest serviceable lifespan – and this is important, because service- ability is a word being bandied about in building envelope circles, on the heels of words such as 'seismic integrity' and 'thermal performance' in ele- ments an envelope should achieve." In short, the emerging trend in building enve- lopes is to develop them to be serviceable, "and when looked at through that lens I would suggest that cur- tain wall's days are numbered, while materials that can be repaired or upgraded due to wear and tear will increasingly be specified in designs," says Ker. Ker is currently preparing a paper that addresses envelope issues on the premise that "detail draw- ings are finding their way to the installation trades but lack the most current advances in system per- formance." This is noteworthy given that Ker earlier this year released a paper on facades, Five Common Mistakes Made in the Facade Industry, which was met with considerable interest (for the record, the mis- takes are: inadequate ventilation; not designing for the co-efficient of expansion and contraction; substructure design omissions and installation shortcomings; poor deflection limit of substructure; and inadequate shop drawings). Terry Bergen, managing principal, and Kevin Pickwick, associate, both with RJC's Building Science and Restoration practice, believe the awareness of building enclosure performance is undergoing a transition similar to that experienced by the mechanical sector years ago, both driven by the goal of energy efficiency. The driver behind this transition towards a "building enclosure first" approach is occurring because evolving policies have shifted from relative to absolute metrics that require project specific calculations to support energy model inputs. Bergen says, "We agree that curtain walls as they are developed today will be relegated to the past, since less glass means better performing envelopes. (CPCQA) CANADIAN PRECAST CONCRETE QUALITY ASSURANCE CERTIFICATION PROGRAM PROGRAM (CPCQA) CANADIAN PRECAST CONCRETE QUALITY ASSURANCE CERTIFICATION PROGRAM (CPCQA) CANADIAN PRECAST CONCRETE QUALITY ASSURANCE CERTIFICATION PROGRAM