Sherway Gardens (officially CF Sherway Gardens) is a large retail shopping mall in Toronto, Ontario, Canada which opened in 1971. Torontonians are most familiar with Sherway’s distinctive white-canopied roof, visible from the junction of the Gardiner, QEW, and Highway 427. Having undergone several renovations, Phase 1 of its latest expansion project opened in September, 2015 and is now home to a mix of luxury brand stores and high-end restaurants.

“This redevelopment engages shoppers in an urban experience with a public face to the exterior of the shopping centre, with places to gather and interact inside and outside. The tone of Sherway’s public realm is set with the sense of arrival at the the new main entrance. As you explore the space, the disappearing curve of the extension’s hallway continuously reveals new retail, creating an inviting shopping experience.” ~ DIALOG

Sherway Gardens: Greening the Grey

Part of a $550 million Canadian dollar project with DIALOG as the Project Architect for the expansion of Sherway Gardens Shopping Centre, the LEED certified 210,000 square foot addition added 50 new stores to the mall including Nordstrom and Saks Fifth Avenue as new anchor stores; a new second level food court that can seat more than 1,000; greatly expanded multi-level parking for 1,200 more vehicles; and more:

Sherway Gardens Shopping Centre’s 9,500 m2 (102,000 sf) pre-vegetated lightweight sedum roof is the largest green roof on a free-standing commercial structure in the GTA (Greater Toronto Area) and makes the shopping mall an example of sustainable development.

The green roof was designed as part of the Stormwater Management Program for the Sherway Gardens Expansion and underground storage cisterns in the parking field were initially required to control stormwater quantity as an additional element. The green roof is visible from the condominium towers at Sherway Gardens Road, and this not only improves the views of the roof of the building to the neighbours in the surrounding community, but the size and storage volume capacity of the green roof offered an opportunity for the required underground cisterns to be reduced in size from the original requirement. (DIALOG).

“We chose the XF301 green roof system as part of the Sherway Gardens expansion because of the key benefits it offers. Our new 102,000 square foot green roof will help slow stormwater runoff from the roof, benefiting both the city and the environment. The green roof also played a role in ensuring that our expansion was LEED certified.” ~ Andy Traynor, General Manager at Sherway Gardens

There are a number of additional benefits to having a green roof such as lower cooling costs, extending the lifespan of the roof membrane, and reducing the city “heat island” effect in the summer. But most important factor for municipalities is often stormwater management.

“Stormwater management is the biggest motivator in some of the oldest cities in North America. They were never prepared for the growth they have experienced so their infrastructure simply cannot manage. In Toronto, for example, it is skyscraper after skyscraper and the infrastructure can barely keep up. We are seeing this across Canada.

The big benefit of green roofs – at least from the perspective of municipal engineers – is that it slows the release of water into a city’s sewer system.” ~ Sasha Aguilera, Next Level Stormwater Management’s Design Ambassador

In the case of the Sherway Gardens installation, the lightweight green roof can retain 33.9 L/M2 or 1.3 inches of rainfall fully saturated. The system is one of the lightest green roof systems available weighing 12 pounds per square foot, fully saturated.

“Sherway is definitely among the largest but there are a lot of green roofs out there. Most are out of sight and therefore out of mind. Many of us have no idea how our cities are teeming with green roofs,” says Aguilera.

According to industry studies, green roofs have been consistently experiencing double-digit growth over the past decade. Many municipalities in North America are recognizing green roofs as part of their stormwater management strategy and are encouraging their implementation through dedicated policies, bylaws and incentive programs.

One impetus for Toronto becoming greener is the successful partnership between the City and building owners. In addition to the city’s Green Roof Bylaw, the Eco Roof Incentive Program offers grants to install a green roof. To qualify, among the things often required, is an engineering report to ensure the building can sustain the additional weight and that the green roof meets construction requirements, specifically, wind uplift.

With wind uplift and fire resistance testing and certificates, Next Level Stormwater Management’s systems have the stamp of approval of engineers and municipal officials alike — and has helped green more than 2 million square feet of rooftops across Canada.

The XF301 Sedum Standard is one of the lightest green roof systems available with a high “water retention-to-weight ratio.” The XF301 Sedum Standard system comprises a root barrier, a drainage mat, two layers of recycled polymeric water retention fleeces and a pre-cultivated sedum mat on a conventional roofing assembly (see 3D above). At a total profile of 63 mm (2.5”), the system weighs 57 kg/m2 (12 lbs/sf) at saturation with a maximum water storage of 33.9 l/m2 (0.81 gal/sf).

The Sherway Gardens green roof has no permanent irrigation as the Next Level Stormwater Management maintenance guidelines still recommend irrigation during periods of drought (note: the living roof has not been irrigated at all in the past 3 years from 2018-2021).

Cadillac Fairview, Sherway Gardens comments, “We are immensely proud of our Sherway Gardens green roof, an exciting extension of Cadillac Fairview’s “Green at Work” program. In fact, this new green roof is the largest green roof on a commercial structure in the GTA. Sustainability is a key principle that drives our success and innovation, and with this new addition to the North Expansion we continue to deliver an environmentally friendly experience for our customers.”

Various bird species have nested and made Sherway their home in a very industrial part of the city.

Cadillac Fairview celebrated the latest phase of CF Sherway Gardens’ $550 million redevelopment and expansion of its new 250,000-square-foot south wing, completed in August 2017. Currently, Cadillac Fairview is building the Sherway Gardens Redevelopment Master-Planned Community which will have eight mixed-use residential towers that will surround the Sherway Gardens Mall.

Sherway joins a long list of notable projects worldwide that have used the Xeroflor system over the past four decades. This technology debuted in North America first when Detroit’s Ford Motor Co. decided to retrofit their existing 10.4-acre truck assembly plant with a green roof. Ford did a comprehensive cost-benefit analysis and searched world-wide for a high performing green roof system that could be installed without costly reinforcement of the factory rooftop. Ford’s architect William McDonough used Xeroflor and has called it “the Holy Grail” of green roofs for its exceptional performance and lightweight features.

Invented in Germany, the patented pre-grown vegetated mat system has been put to various wind, fire and root penetration tests and won many prestigious accolades such as the Product Innovation Award (PIA) from Architectural Products Magazine. Xeroflor is also Cradle to Cradle (C2C) certified for environmental sustainability.

Greening opportunities Canada-wide

Retrofits offer new opportunities for greater sustainability. With Canada’s building stock being relatively old, there is much to be done. “According to Statistics Canada (2000), about 70% of the country’s commercial and institutional buildings were constructed before 1980,” says Karen Liu, Green Roof Specialist for Next Level Stormwater Management.

Retrofitting them with more efficient, green technologies can have significant impact on the building sector’s overall environmental footprint in terms of energy efficiency and stormwater management. Most often, though, structural capacity has been the issue of greatest concern. With the availability of lightweight green roof systems, such as the one Sherway uses can turn almost any rooftop into a green oasis and achieve greater sustainability

Besides Sherway Gardens other notable Next Level Stormwater Management green roofs include the Coquitlam and McLoughlin Water Treatment Facilities, the Canadian Forces Seaforth Armoury as well as many high end residential and several commercial buildings such as GTA’s IKEA.