By Brent Bellamy, Creative Director and Architect
Republished with permission courtesy of the Winnipeg Free Press.
Redevelopment gives city another must-visit site
You would be hard-pressed to find a North American city the size of Winnipeg blessed with a similar number of high-quality cultural organizations and amenities.The Canadian Museum for Human Rights and the zoo’s Journey to Churchill are the most recent major additions to the city’s cultural scene, but the development is not stopping there.
Image: The Butterfly House will be designed to give visitors to the Leaf the impression they are soaring above the rest of the building.
The Manitoba Museum recently began an expansion of Alloway Hall, and the Winnipeg Art Gallery is progressing on its mission to build the world’s premier centre of Inuit art.
In Assiniboine Park, designs are underway for a unique horticultural attraction that will be the final piece of the park’s modern redevelopment.
Located at the southeast corner, Canada’s Diversity Gardens will transform the area that is currently home to the Formal Gardens. With a strong visual presence along Corydon Avenue, this location will present a dramatic new face for the park in the community.
Designed by Winnipeg’s HTFC landscape architects, the outdoor gardens will feature a series of experiences representing Canada’s multicultural diversity. The Indigenous People’s Garden, designed with direction from First Nations advisers will celebrate aboriginal heritage and culture. A woodland area called the Grove, will frame the overall development to the north.
The current diagonally configured secondary entrance at the corner of the park will be closed to vehicles to create a formal pedestrian procession down the centre of the site through what will be the Cultural Mosaic Gardens, focusing on ornamental plantings of northern hemisphere nations.
At the culmination of the formal axis will stand the showpiece of Canada’s Diversity Gardens, the breathtaking Leaf structure, named for its resemblance to two overlapping autumn leaves that have fallen gently to the ground. This new building will replace the functions of the existing Conservatory and house the indoor, tropical and Mediterranean biomes of the garden.
The building’s design team, made up of Winnipeg’s Architecture 49, Toronto’s KPMB Architects and Germany’s Transsolar climate engineers, is the same group that created Portage Avenue’s Manitoba Hydro Place, recognized as one of the most environmentally sustainable buildings in the world. Many of the same environmental strategies will be incorporated in the new building at Assiniboine Park, which focuses on using as few mechanical components as possible, instead relying on natural and passive systems.
Image: Redevelopment of Assiniboine Park will give the area currently known as the Formal Gardens and entirely new look.
The orientation of the building was a critical first decision in achieving these goals. From the north, the visually solid end of the building that houses functional spaces such as a restaurant, meeting rooms and a banquet centre will rise out of the ground, protected by earth berms up to six metres high. These berms will create a thermal mass, retaining heat and sheltering the building from the prevailing winter winds. They will also cover an extensive geothermal-energy system to be incorporated into the building.
A unique series of concrete earth ducts will ventilate the interior space from underground, using the temperature of the Earth to naturally heat and cool the air in different seasons. This air will be naturally humidified by water features that are incorporated into the biome experience, including waterfalls that can be viewed from different vantage points as visitors progress through the spaces.
The botanical gardens will be housed on the south side of the building, positioned to maximize solar gain. A light steel diagrid frame tower will rise up through the centre of the space, standing almost 10 storeys high, a few metres taller than the iconic park pavilion. This central core will house the building’s vertical circulation and function mechanically in ways similar to the solar chimney on the Manitoba Hydro building, using convection to naturally pull air through the interior space, exhausting it in the summer and harvesting its heat in the winter.
The tower is also the centrepiece of a structural system that will make the Leaf unique in the world. Most conservatory-type buildings are made of glass supported with heavy steel structural frames. This can diminish the feeling of openness and transparency within the space.
The tower of the Leaf will replace the traditional column-and-beam configuration, acting structurally like the centre pole in an old canvas tent. A series of tensile cables will spiral dramatically outward from the tower beyond the perimeter of the building and then pegged to the ground, similar again to a tent structure. These elegant radiating cables will support a 90 per cent transparent ETFE roof system. ETFE stands for ethylene tetrafluoroethylene and is essentially a series of big Teflon-like pillows inflated with low-pressurized air to provide insulation and strength. Pillows on the Leaf will be up to 60 metres long, three metres wide and one metre thick. The system includes sensors that can automatically increase the air pressure in the pillows by up to six times, if greater strength is needed in case of heavy snowfall or other loading.
The dramatic versatility of ETFE was demonstrated on the Water Cube pool at the 2008 Beijing Olympics and is currently being used on the roof of the new Minnesota Vikings football stadium. Having less than one per cent the weight of a glass skylight system, the light, tensile-cable structure can be used on the Leaf to give the roof an organic, draped appearance, creating an elegant form that reflects the traditional image of shelter around the world.
The exterior walls will enhance the feeling of transparency, being constructed of full-height glass, also supported without heavy columns, but with cables and spider-shaped clips that replace traditional window mullions. This extreme lightness of structure and transparency of the building’s skin will create the transcendent experience of being immersed into a new world under an open sky, a powerful sensation in a harsh winter city.
The crescendo event in the Leaf will be a visit to the Butterfly House that from the moment of entry, will appear to soar above the rest of the building like a great tree branch extending from the centre. The procession through the building will be like climbing that tree, and when the top is reached, visitors will feel as though they are floating with the butterflies high over the tree canopy of the city, looking all the way to the downtown skyline.
Canada’s Diversity Gardens will be unique in the country and the Leaf will certainly not be your grandmother’s Conservatory. The design team travelled the globe, inspired by the Eden Project in England and structures as far away as Kazakhstan. The result, however, will be a piece of architecture that is like nothing found anywhere else in the world.
The optimistic goal is to have the project complete in autumn 2019. When it opens, it will be a place for tourists and residents alike to completely immerse themselves into a new world, taking its place alongside the city’s other cultural amenities and becoming a celebrated Winnipeg experience for decades to come.
Brent Bellamy is creative director at Number Ten Architectural Group.