Landscape Design

Team Chestnut from left to right: Man Lam Cheng, Zhiyuan Zhu, Todd Douglas, Behnaz Assadi, and Nima Javidi, along with Jury Chair Susan Speigel.

Applicant details were kept anonymous from the jury—using tree species as assigned pseudonyms for the teams—so that each submission could be evaluated on its own merits. In this way, competitions can be an excellent way for emerging professionals or innovative thinkers to find a platform for consideration. 

After careful review against the competition criteria, Team Chestnut was awarded the top prize of $20,000 and the project contract. The team—led by Architect Nima Javidi and landscape architect Behnaz Assadi of JA Architecture Studio, with landscape architect Todd Douglas of Janet Rosenberg & Studio and civil engineer Kayam Ramsewak of MTE Consultants—proposed an innovative and sustainable design.  

Titled, The Grounding Meadow  the jury favoured the elegant and minimalist intervention that invites the natural features of the Don Valley context onto the property to create a seamless relationship to the surrounding land. The design also echoes the existing building aesthetic while introducing discreet functional elements such as improved stormwater management features. Further details are available in the announcement press release and the Jury Report. 

The OAA is thrilled to have officially kicked off construction on the project on June 25, 2026, with an intimate groundbreaking ceremony at its headquarters. 

Ruth Cawker’s original design for the OAA Headquarters features large glass windows framing the sweeping views over the Don River Watershed context. Throughout its lifespan, the building has celebrated its natural surroundings, and this landscape design complements and enhances that ethos. 

For The Grounding Meadow, re-naturalization of the entire site has remained a crucial priority to reflect its location adjacent to the Don River watershed. All existing sod will be removed and replaced with plant materials specific to a native meadow landscape and the anticipated wet and dry areas of the site, inviting the valley right onto the property in a very direct and immediate way.

The OAA Headquarters is situated on the traditional territory of the Mississaugas of the Credit, as well as the Anishnabeg, the Chippewa, the Haudenosaunee, and the Wendat. The Grounding Meadow pays homage to Indigenous communities by including plants of cultural significance, including a diversity of perennials and grasses. This will consequently attract pollinators, wildlife, and birds, activating the surrounding landscape with its natural activity. Over the years, it will naturally continue to evolve into a majestic meadow. 

Rethinking the entry experience required considering both form and function to arrive at a design that makes everyone feel welcome and safe while creating connections to the surrounding Don Valley.

The Grounding Meadow promotes a powerful landscape gesture that complements the OAA Headquarters in a profound and extraordinary way. The entry walkway will be transformed into a bridge, allowing the Don River ecosystem to connect with the building. An upgrade from the current paved entry, the gentle slope from the public sidewalk along Moatfield will offer improved accessible access, leading visitors to the front door of the building with a view overlooking the lush meadow landscape below. The walkway will be elevated much like the Headquarters is elevated, providing a sense of continuity as a freestanding, floating structure sitting atop a hill.

New bollards will be both a design feature and barrier between the pedestrian deck and main driveway, with carefully considered lighting choices illuminating the way for pedestrians and motorists alike. 

Situated on the banks of the Don River watershed, the site offered an opportunity to rethink responsible relationships with water. The Grounding Meadow presents a theme of being light on the land as it works directly with the site in a minimalist way.

The design will allow water to freely run underneath the wild meadow, bringing a more natural ecology to the site and welcoming stormwater to support and sustain the habitat. The new onsite gardens are not only beautiful to behold, but also cleverly designed—they use bio-retention cells to capture storm water outfall from the entry drive and parking areas.

The existing driveway will be replaced with new pavers with a trench drain included to divert drainage to a new rainwater garden to the south. 

TEAM

Design Team 

Architect – JA Architecture Studio

Lead: Nima Javidi, Behnaz Assadi 

Landscape Architect – Janet Rosenberg & Studio 

Lead: Todd Douglas 

Structural Engineer – Faet Lab 

Lead: Shannon Hilchie 

Civil Engineer – MTE Consultants 

Lead: Joseph Asztalos 

Electrical Engineer – WSP

Lead: Rochelle Chong 

Accessibility Consultant – Level Playing Field

Lead: Darby Young

Lighting Designer – Gottesman Associates 

Lead: Deborah Gottesman 

Construction Manager/General Contractor 

Somerville Construction

Lead: Alexia Macleod, Tony Vizzini