In Green Building, Climate is Everything

Aug 17 • Articles, Cityscape, Sustainability • 1713 Views • 1 Comment on In Green Building, Climate is Everything

Many people think that European architects are more forward thinking than their Canadian counterparts when it comes to energy conservation, but practitioners from the Great White North are the best in the world at designing buildings suitable for their climate.

By Deidre Miller…

 

Many North Americans and Europeans have crossed the Atlantic for a visit or two during the tourist season, but few are aware of the very dramatic difference in climate between the two continents. 

 

North American architects tend to be very impressed with the sustainable design trends in Europe. They sometimes assume that if European buildings use less energy than North American buildings, it’s because the Europeans are smarter and greener. If you’ve lived in both North America and Europe, it’s very clear that climate has as much – possibly more – to do with lower energy costs in Europe than any design-related consideration.  Particularly in Canada, buildings are carefully designed to mitigate extreme swings in temperature and humidity.

 

Extreme Temperature Swings

The mid-continental climate in southern Canada and the northern US is extremely variable.  There is nowhere in the world except north central China where the temperature swings are so great from season to season.

 

The chart below compares the average low temperatures for London, Rome, Stockholm and Montreal.  Montreal is far colder than any major European city during the winter, but in the summer, it’s hotter than anywhere in northern Europe. Only a southern European city like Rome is hotter.

 Graph

Of course, the average low temperature chart doesn’t tell the whole story. The average high temperatures matter, too. In midsummer, the average high in Rome is 32°C. Montreal’s average high temperature is around 27°C, and London and Stockholm’s are barely over 20°. Cities like Toronto and Montreal can get very hot in the summer due to the urban heat island effect, and the summer climate in the eastern half of the North American continent is humid, as well.

 

In the northern US and southern Canada, it’s hot enough to be uncomfortable in the summer. In the winter, it’s often cold enough to kill. Modern buildings are heated in the winter and cooled in the summer. The older buildings without air conditioning become dangerous during urban heat waves. For example, 750 people died over 5 days in the 1995 Chicago heat wave when the temperature exceeded 40°C. Toronto sometimes sees similar temperatures.

 

Building Design Challenges

In a city like Toronto or Montreal, the summer brings hot and humid outdoor conditions, while building interiors are drier and cooler. In the winter, the situation is reversed. The interiors are warm and humid and the weather outside is cold and dry. This seasonal reversal poses a real challenge in building design, and particularly in the design of building envelopes – walls and roofs – and heating and cooling systems. Roof and wall sections need to be able to weather a reversal in the movement of heat and moisture. That means that in order to design buildings that will perform well 12 months a year, architects must have a rational, detailed understanding of building science. Building science, sometimes called building physics, is the study of how buildings interact with heat and moisture, and Canada has been doing groundbreaking building science research for decades.

 

Canada’s Groundbreaking Building Science Research

The National Research Council’s Centre for Research in Construction wrote the rulebook for Building Science in Cold Climates starting in the 1970s, and it is still sponsoring valuable work. Their archives are a treasure trove of specific advice on building design. Natural Resources Canada another NRC – is also contributing to Canadian expertise in green building.

 

Many American architects and engineers already know about the NRC’s building science research and refer to their online resources regularly. However, most architects and engineers in the U.K. and on the European continent aren’t aware of what the Canadians have to offer in this very important area of design. Since the research took place starting decades ago, it was included in the training of the current generation of Canadian architects and engineers, and it greatly influences their work. Canadian building designers have an impressive level of sophistication when it comes to sustainable design.

 

To see Canadian expertise in building science at work, look at some of the zero-net energy buildings they’ve designed for Canada’s challenging climate:

– The Centre for Interactive Research on Sustainability (CIRS) on the UBC Vancouver campus.

– The Riverdale NetZero Project, a semi-detached house in Edmonton, Alberta.

– Del Ridge Corporate Centre in Markham, Ontario

– Zero net energy homes are even starting to be mass produced in southern Canada

 

To find out more about differences in climate throughout the world, take a look at the charts at Climate-Charts.com.

CityWalk: Ossington Avenue -- Toronto

Toronto’s Ossington Avenue after a light dusting of snow. This is the warmest major city in Canada.

 

Deidre Miller is an engineer with an architecture degree who has lived in the U.S., Canada and the U.K. and worked in building design, evaluation and regulation. 

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  • Joe Calarco

    A lucid vetting of some rarely discussed issues. The impact of global warming on zero-net energy building design would also be of some value, I believe.

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