Two Old Mill, An Award Winning Green Roof – Case Study

Condo Rooftop Transformed into Biodiverse Green Space

Download the PDF Case Study Two Old Mill, Toronto, Ontario

About Award of Excellence

Varied Landscape Creates an Urban Habitat

Green roofs provide an enjoyable green space for building residents as well as an urban habitat for insects and pollinators.  A biodiverse green roof offers greater conservation and environmental benefits, such as stormwater management, compared to conventional roofs.

Vibrant Palette

The extensive lightweight and “soilless” system used on Two Old Mill is 30 mm thick and is comprised of loose-laid base layers and a pre-vegetated mat. The mat includes 8-10 species of sedum and arrives mature with 80 per cent foliar coverage.  This extensive system is beautifully blended with a vibrant palette of perennials planted in an intensive green roof system.


Beautiful mix of Extensive and Intensive Vegetated Roof Systems

The intensive green spaces have up to 1200 mm of engineered growing medium that supports various species of grasses, shrubs, deciduous evergreens, perennials and vines. Over 50 per cent of the species selected for the project are native to the area.


Recipient of the Award of Excellence, Green Roof For Healthy Cities 2018

Janet Rosenberg & Studio led by landscape architect Greg Warren designed the green roof to meet the Toronto Green Development Standard Tier II.    Kirkor Architects designed the Tridel Condo to achieve LEED Gold Certification.

Enjoy more beautiful photos 

Variety of native plantings in extensive system combined with extensive sedum blanket




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Next Level Stormwater Management logo in bold blue with logo above in blue and greenNLSM has supplied more than 2.5 M SQFT coast to coast

NLSM is Canada’s leading supplier of pre-vegetated roofs such as LiteN’Less™, Xeroflor® and StormCap™ systems. We customize to local requirements. Offer warranty& maintenance support, provide ​stormwater calculations specific to location ​and building/roof type, stormwater test data & related innovative hydrologic modeling. Email or call (416) 637-5772 Ext 1.