The need for energy performance targets

For this project, a thermographic survey confirmed there are no apparent defective VIPs and they have significantly reduced heat loss recorded through the spandrel dual-sealed insulating glass (IG) units and seals. Images courtesy Dow Corning
For this project, a thermographic survey confirmed there are no apparent defective VIPs and they have significantly reduced heat loss recorded through the spandrel dual-sealed insulating glass (IG) units and seals.
Images courtesy Dow Corning
The new Halifax library will have a higher-performance building envelope system. Image courtesy Cedaridge Services Inc.
The new Halifax library will have a higher-performance building envelope system.
Image courtesy Cedaridge Services Inc.

VIP systems are being looked at in Canada for learning centres, such as the new Halifax Central Library (Figure 10). In landmark projects in Europe, slim VIPs of 40 mm (1.6 in.) have been used to achieve the higher energy efficiency needed for NZEB. These assemblies have reduced the wall thickness from 240 mm (9.4 in.), essentially giving back 200 mm (8 in.) of interior rentable/saleable real estate. Innovative landmark projects are being sought in North America, especially at universities where there are education opportunities.

As VIPs are relatively new to Canada and internationally, it is critical to assess their application at the pre-design phase of building commissioning so schedules are not adversely impacted and innovative financial initiatives (e.g. Ontario’s GreenFit program) and NRC technical support can be considered. Natural Resources Canada’s (NRCan’s) Canmet and CMHC have also looked at continuous VIP behind an exterior cladding with a rainscreen drainage cavity in wood-framed housing (Figure 11). There are great opportunities to improve the energy performance of housing if the exterior cladding generated solar power, especially in high-EUI multi-family dwellings. Wood mid-rise residential buildings (For a discussion on residential green buildings, see this author’s article, “What are Canada’s Next Green Leaps?” in the September 2011 issue of Construction Canada). with VIPs as an alternate to predominately all-glass structures could be an essential part of Canada’s goal of improved building energy efficiency and achieving cost savings.

As VIPs gain more market share, it is necessary to establish a standard for public safety and performance. At the aforementioned ISO meetings, SCC took a leadership role in assuming responsibility for development of a VIP standard.

Promising solar-power-generating glazing that could be made with different colours. It also provides shading. Image courtesy Cedaridge Services Inc.
Promising solar-power-generating glazing that could be made with different colours. It also provides shading.
Image courtesy Cedaridge Services Inc.
A sample detail of continuous VIPs behind an exterior cladding with a rainscreen drainage cavity in wood-framed housing. Image courtesy CanmetENERGY
A sample detail of continuous VIPs behind an exterior cladding with a rainscreen drainage cavity in wood-framed housing.
Image courtesy CanmetENERGY

After higher building energy efficiency is achieved, use of renewable energy-producing systems must be considered for NZEB. There are key global developments of renewable energy systems that can be integrated into the glass, spandrel, and other panels on the façades. These solar glass panels are an alternate to adding photovoltaic (PV) panels on the roof, which requires additional structural supports and penetrations of the roof or, worse, are installed on valuable land.

This author investigated a promising solar power glazing in the United Kingdom (Figure 12) that could be made with different colour shadings and the solar film between the glazing generates renewable solar energy. According to a study completed for the University of Oxford, in the case of a 213-m (700-ft) skyscraper in Texas (Climate Zone 2) with 60 per cent of the façade installed with solar glass panels, about 5.3 MWhr of renewable energy would be produced daily.

It is also critically important for financial institutes and real estate trusts to embrace a European style policy with LCC considered in building upgrades and valuations. Taking into account rising energy costs for a 30-year LCC period would enhance the value of real estate portfolios and reduce long-term building operating costs. The 30-year LCC is shorter than the EU-permitted estimated economic lifecycle for the system, which could be, for example, a half-century for curtain walls. It is best to connect the economics of the system with the financial lifetime.

Conclusion
With energy performance targets, lower-cost lifecycle opportunities include insulation products and renewable energy options that can be analyzed as part of the commissioning process; overall costs can be reduced. One must measure energy performance to a uniform consensus standard to be able to manage the EUI and reduce consumption.

It is smart to act now on energy performance targets to see how existing or planned buildings compare with the coming codes and standards. Cost-optimal levels of energy performance that reduce EUIs can be implemented. True sustainability is about reducing energy costs and moving our buildings toward near-zero energy.

Bob Marshall, P.Eng., BDS, LEED AP, sits on the National Research Council’s (NRC’s) Task Group on Energy Targets. He is Canada’s appointed expert on the International Organization for Standardization (ISO) TC 163-TC 205 WG4 on Energy Performance, and the voting member for TC 163/SC 2 on calculation methods. Marshall chaired the U.S. Green Building Council’s (USGBC’s) Greenbuild 2011 ‘Best of Canada’ stream of educational seminars, and is a member of the council’s education committees. The founder of Cedaridge Services, he also provides senior consultant services to Stephenson Engineering based in Toronto. Marshall can be contacted via e-mail at bmarshall@stephenson-eng.com.

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