Highrises put city in the shade
Richard White For The Calgary Herald Saturday, December 02, 2006
Designing buildings and public spaces in winter cities like Calgary is very different from cities like Barcelona or Vancouver. In his 1995 book, Northern Cityscapes: Linking Design to Climate, Norman Pressman illustrates how too often, designers and architects have a perpetual state of summer in mind when they design public spaces (the spaces work well when it is warm outside, but expose people to chilling winds and cold shadows in the winter).
Calgary's Plus-15 system is our most obvious adaptation to winter.
It allows downtown workers and their clients to move from offices to hotels, retail shops and parkades without having to deal with the harsh winter climate. People who criticize the Plus 15 system for destroying the vitality of city streets don't appreciate how the Plus 15s add vitality by allowing people from the edges of downtown to get to places like Bankers Hall or Stephen Avenue when the weather is poor. It is common knowledge that when the weather is nice, people walk outside; when it isn't, they walk inside.
Nobody ever says Montreal's underground system destroys the street life on St. Catherine's Street. The creation of Calgary's Devonian Gardens in 1977, as a wonderful tropical oasis, is another adaptation in Calgary to our winter climate. It created a wonderful year-round park space for all Calgarians to enjoy. Our indoor water slides and our wonderful recreation centres are also examples of adapting to winter.
Not all adaptation needs to bring people inside. Calgary is fortunate to have plenty of sunshine in the winter that can turn a cold day into a very pleasant one. To do so, we design buildings that allow the sun to shine on our sidewalks, pathways or plazas in the winter months. While we have taken some steps to protect and capitalize on our sunshine, we can do better.
Building heights in the downtown are restricted to allow more light on the Bow River pathway, Stephen Avenue and Olympic Plaza. But there is pressure to allow for exemptions as the demand for more and taller office buildings increases. The sun along 8th Avenue in the winter will be less when Bankers Court, Penny Lane and the Homburg developments along 9th Avenue are completed. Bright sunshine currently warms up the skating rink at Olympic Plaza in the middle of winter, but what happens if tall buildings are built on the neighbouring blocks?
As Calgary builds more highrises, the amount of sun that will reach the sidewalks and public spaces of our city centre will be less and less. James Short Park -- already in shade most of the time due to the TransCanada PipeLines, Petro Canada and Sun Life towers -- will be totally engulfed in shade when Encana's new building is constructed. The courthouse park will be in shadow due to the new courthouse complex, Penny Lane and the proposed new ESSO tower.
Calgary needs to rethink if taller is better. Probably the best example of poor winter design is the First Canadian Centre. For some reason, the developer oriented the building to the northwest and not the southwest.
As a result, there is no plaza on the sunny southwest corner, while the northwest plaza is in shade almost year-round. Bankers Hall has a multi-million-dollar plaza on its southwest corner that is always empty because it is in shade all the time. What a waste.
The importance of sun can be seen along 17th or 11th avenues, where the majority of the shops are located on the north side of the street. Why? Because pedestrians love to walk in the winter sun. The Ship and Anchor patio is used year-round. Why? Because it gets sun in the winter.
We have to let the sun shine down on our urban sidewalks, plazas and parks. What we also need are more pocket parks and plazas -- small spaces that get lots of sun and need only 10 to 20 people to animate them.
The best example is the indentation next to the Roasterie on the east side of 10th Street N.W. It is full of people year-round. There are no special banners, benches, decorative bricks or other enhancements, just coffee and sunshine. Creating large parks and plazas becomes problematic in winter cities because they need hundreds, if not thousands, of people to make them animated. This just isn't going to happen for six months of the year.
For years, Calgary has given developers a density bonus (additional floors) if they build arcades (covered walks) like the one at The Bay on Stephen Avenue. In warmer climates, such areas work great and are often used as patio areas, allowing people to get out of the summer sun. In Calgary, they are always cold and gloomy places. They often become shelters for the homeless and panhandlers, and the pillars in the middle of the sidewalk make walking more difficult.
Why are we still giving a bonus for creating negative urban spaces? Even the planting of trees and types of trees needs to be carefully planned in a winter city. A row of large pine trees planted too close to the sidewalk can cast a shadow on the sidewalk or a pathway for several months in the winter, creating cold icy conditions that nobody wants to use. While a row of elms creates a canopy that is inviting to walk under, it still allows the sun to shine on the sidewalk in the winter.
The positioning of buildings, gaps between buildings, and building shapes must be taken into account to avoid the creation of wind tunnels. The Nexen building, placed at an angle to Calgary's predominately west winds, creates a wind tunnel that sometimes is so bad, the wind actually creates a whistling sound. Good design that is appropriate for Calgary's climate, and sensitive to the site, is critical to creating good urban places where people want to work, live and play. It doesn't require innovation, but it does require insight and investigation.
Richard White is the director of operations and communications at Riddell Kurczaba Architecture.
Some ideas for winter city design:
- Ensure sun shines on sidewalk and plaza areas;
- Avoid creating wind tunnels;
- Create more pocket parks and plazas;
- Avoid arcades;
- Plant trees carefully.