A rising ETFE roof tops Canada’s “Leaf” Botanical Gardens
KPMB engineers are shaping a greenhouse garden in Winnipeg
A new botanical garden called The Leaf has taken root WinnipegAssiniboine Park Assiniboine Park invites visitors to immerse themselves in the world of plants and nature. Designed by KPMB Architects in collaboration with Architecture49, Blackwell Structural Engineers and HTFC Planning & Design, The Leaf brings 35 acres of sustainable architecture and lush gardens to Manitoba. With its mounting glass on the roofthe greenhouseThe styled project represents KPMB Architects’ first venture into the world of horticultural design, aiming to foster a deeper understanding of the natural world while setting an impressive precedent for future endeavors.
Photos © Emma peter | @emaphotography
New Assiniboine Park icon
A leaf This is an important addition to the Assiniboine Park Conservancy’s ambitious redevelopment plan, which has been breathing new life into this century-old park since 2009. Architects At KPMB she designed it as an extension of the park’s existing attractions, including the Assiniboine Park Zoo, to create a dynamic and engaging ecosystem that combines education and architecture.
At first glance, The Leaf celebrates the dialogue between architecture and nature, with its signature roof design inspired by the Fibonacci sequence, a mathematical phenomenon often found in sunflower spirals and nautilus shells. The complex cable network structure spreads gracefully around the building, reminiscent of a blooming flower. Lights and reflectors artfully placed inside the building mimic the atmospheric effects of natural moonlight, thunderstorms, and the northern lights. This beautifully curved organic form reflects the simplicity and complexity of the diverse plant species it houses.
The glass walls that envelop the structure open towards panoramic views
A center for botanical education and exploration
Comprised of four distinct biomes, The Leaf hosts over 12,000 trees, shrubs, flowers and 400 unique plant species. Visitors begin their journey at the Hartley and Heather Richardson Tropical Area, which features a winding trail and the tallest indoor waterfall in Canada. The Mediterranean region showcases a vibrant tapestry of colours, textures and fragrances from Greece, Italy, South Africa and Chile. The Babs Asper Display House dazzles with rotating floral displays, exploring seasonal and global themes, while the Shirley Richardson Butterfly Garden offers a covered walkway overlooking the Tropical Biome. The glass walls that envelop the building open to panoramic views, blurring the line between inside and outside, and allowing visitors to enjoy the surrounding landscape.
The intricate roof structure spreads around the building recalling a blooming flower
The Leaf is among the largest ethylene tetrafluoroethylene (ETFE) buildings in Canada, demonstrating the material’s superior thermal performance compared to traditional greenhouse materials. Winnipeg’s extreme temperature changes require robust solutions, and the ETFE roof provides exceptional transparency, ensuring enough sunlight reaches the interior biomes. Natural ventilation and an open geothermal system, supported by subsurface water flow, maintain ideal temperatures within the biomes, while mist fans provide cooling for both plants and visitors, ensuring a comfortable environment.
The park features a winding path and the tallest indoor waterfall in Canada
‘We Winnipeggers celebrate weather extremes, but even the hardiest of us appreciate a respite from the long, cold, dry winter.,’ Lee McCormick, Managing Director at Architecture49 Manitoba, writes. ‘The Leaf is an affordable and accessible urban oasis in the winter desert that transports one temporarily away and connects all people to the plants of distant lands. The facility is a fantastical technical achievement that lifts the spirit by amplifying natural systems to allow visitors to awaken their appreciation for the world of horticulture while the outside world slumbers..’
The project creates a new dynamic ecosystem with an educational and architectural character
