In September 2006, Toronto Botanical Garden officially reopened after a $7.2 million revitalization project and is proud to feature The George and Kathy Dembroski Centre for Horticulture, which showcases environmental sustainability and architectural beauty. The building exhibits an impressive 8,100 ft2 glass pavilion that houses offices, event and educational spaces, a library and garden shop. One of the most striking features of the pavilion is its sloping green roof. Half of the roof area is planted with drought-resistant sedums and the other half with native wildflowers. The green roof minimizes heat gain through the building's roof and reduces the urban heat island effect. Stormwater runoff from the roof is collected in a cistern and fed into the garden's irrigation system.
Landscaping materials around the pavilion were chosen for high reflectivity, further reducing the build up of heat. In addition, absorbent landscaping surfaces were used to soak up rainwater where it falls. The combination of the green roof, two 30 m3 rainwater cisterns, and soft landscaping surfaces results in a remarkable 37% reduction in stormwater runoff. Indoor air quality was made a priority by specifying building products and finishes that do not off-gas volatile organic compounds. Natural beauty comes indoors, as the design of the building allows for exceptional daylighting. All interior spaces are drenched with filtered natural light and have a line of sight to the outdoor landscapes and the vast sky above. Potable water use within the building has been reduced by 21%. This is achieved through the use of low-flow plumbing fixtures, a waterless urinal, and low-flow lavatories.
Approximately 90% of the demolition materials were diverted from landfill sites. The architect was able to salvage and reuse most of the existing material and much of the unused portions were taken offsite to be recycled. The new addition and the existing building combined use 30% less energy than a building built to current energy standards. The building shell is well insulated and new windows are high performance (argon-filled double glazed low-e glazing). The mechanical system consists of high-efficiency mechanical equipment, including an energy recovery ventilator. Both building ventilation and lighting are automatically controlled by occupancy sensors: fans and lights are activated only when interior spaces are in use.
2007 Water Conservation Award, Landscape Ontario, 2006 Landscape Architecture Design Award (The Design Exchange), 2006 Green Toronto Award for Green Design