solar

Green from the outside-in

Innovative exterior building products
Monday, September 17, 2012
By Rodney Wilts

There has been an incredible explosion of products and services available to those looking to create environmentally advanced buildings.

Here is an update on innovative green products for the building exterior.

Windows
R3.5 used to be considered a good window, however, there are now mass market alternatives claiming R10 and better.

SeriousWindows is likely the best known company for manufacturing high-performance windows, which are now available in Canada. The company offers windows ranging from R7 to R20, with options available to optimize solar heat gain and good visible transmittance.

Closer to home, Thermotech has foregone the race to claim the most inflated R-value. Instead, it has focused on climate and orientation-specific windows, with the aim of making each window a net energy positive contributor to the building.

Furthering the window revolution is an emerging trend of “smart” windows. These windows automatically adjust the amount of solar heat gain depending on the needs of the building.

Similar to glasses that darken when the sun comes out, electrochromic and gasochromic windows alter the visible transmittance and solar heat gain of a window depending on the environmental conditions.

Electrochromic windows enable building operators to allow sunlight (and heat) to penetrate into a building when desirable but limit solar heat gain when the sun is out and the building is in cooling mode.

While far from commonplace, switchable glazing is now slowly making inroads in the market with great promise for further energy savings.

Cladding
Once a rarity sourced at a considerable premium, Forest Stewardship Council (FSC) certified wood options are now widely available across the country and often at no or a negligible added cost.

Higher levels of recycled content are now available with a variety of metal siding options.

Exterior green walls like those offered by Elevated Living Technologies  can make a dramatic statement about sustainability, while improving the thermal performance of the wall system.

Two additional cladding options are torrefied wood and EcoClad.

Torrefied wood comes from a centuries old Japanese tradition called shou-sugi ban where cedar wood was charred. The charring of the wood made it unattractive to insects, less susceptible to rot and made for a dramatic appearance. Several North American manufacturers are now offering an updated version of this ancient practice.

Torrefaction of wood is a non-chemical treatment characterized by subjecting the wood to very high temperatures. Torrefied wood has practically no internal moisture, which makes it very resistant to shrinking, warping, biodegradation and insect pests. USD is a Canadian manufacturer offering FSC certified torrefied wood products.

EcoClad is an innovative new cladding product offered by the same company (Klippert Technologies) that brought the industry Paperstone. EcoClad is a bio-composite panel that combines post-consumer recycled paper with rapidly renewable bamboo fibres. Even the binders used are environmentally sound, sourced primarily from corn and cashews.

Another innovation in cladding is the emerging trend of building integrated photovoltaics (PV). Recognizing a massive solar array perched atop a building is not everyone’s idea of great architecture, photovoltaic manufacturers are now looking at ways to better integrate PV into the roof and façade of the building. Dow’s Power Shingles are just one example of a subtle use of PV technology intended to be integrated into the architecture of a building. If the Solar Decathlon is an indicator of future trends in green architecture, the industry will surely see an increase in use of PV doing double-duty as power producers and exterior cladding.

Landscaping
Emerging trends point to landscaping for wildlife habitat and to grow food.

LEED (Leadership in Energy and Environmental Design) credits for elimination of irrigation systems and promotion of native and adaptive species have encouraged landscape architects to focus on butterfly gardens and other targeted habitats.

Food growing is now becoming increasingly used as an ornamental feature as well as a sustainability statement. With 25 per cent of the typical Canadian’s ecological footprint related to the food eaten, bringing food production to the ultimate local level makes good sense. Two prominent Canadian examples of food growing as landscaping include the Cirque du Soleil headquarters in Montreal, and Enermodal Engineering’s headquarters in Kitchener, Ont. Even condominium developments have gotten into the trend. Cathedral Hill, a Windmill Development project in Ottawa, which is targeting LEED platinum certification, plans to have rooftop vegetable growing plots available for residents.

Rodney Wilts is a partner at Guild Green Solutions in Ottawa.

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