Rail Deck Park poses big structural challenges but the large green space proposed for downtown Toronto could become a reality with community features and retail along its edges, say two Carleton University architecture students.

The proposed park would essentially be a bridge with landscape on its deck, say David Anderson and Marisa Renaud, students at Carleton's Azrieli School of Architecture and Urbanism in Ottawa.

"It's definitely possible," Anderson, an undergraduate student, told Metro Morning on Monday.

"Projects like this have been done in other cities before and the opportunity of adding a large amount of green park space in the downtown core is definitely feasible from a structural point of view and an economic point of view. Yes, it's a big challenge but an exciting one."

Anderson and Renaud have been asked to explore concepts for the park as part of Carleton Studio, a six-week program developed by the design firm DIALOG. The firm, through its Toronto studio, is providing Carleton University students with industry experience and access to professional networks, and it chose Rail Deck Park as a learning opportunity.

David Anderson and Marisa Renaud, students at Carleton's Azrieli School of Architecture and Urbanism in Ottawa, talk to CBC's Matt Galloway on Metro Morning about Rail Deck Park. (CBC)

Last October, Toronto city council approved $2.4 million for design work on the park, which would span 8.4 hectares in the waterfront railway corridor. The park, as proposed by Toronto Mayor John Tory, would involve a deck built over the downtown rail corridor, with parkland created on top.

It has been estimated that the park would cost $1.05 billion.

Renaud, a master's student, said the main structural challenge comes from the "bridging" required to build the park.

"Usually, when you start a building, you dig a hole and build over the hole. This isn't anything really new for us to do," Renaud said.

"Essentially, we have been looking at this as a giant bridging project. For structure, we have been looking at all the different ways you can bridge across things and how much depth we need to that structure, if wanted to add things like trees. That sort of determines how deep we make the structure, what street conditions we have, whether you can access it at street level or you have to go up ramps," she said.

Rail Deck Park, as proposed by Mayor John Tory, would involve a deck built over the downtown rail corridor, on top of which would be created parkland. (Jennifer Keesmaat/Twitter)

"The big challenge for this project is we are trying to bridge over a space that was never meant to be connected. The rails were put there without really any intention of connecting the north to the south in that region."

Renaud said there are many factors to consider when designing the park, including the spaces needed for pedestrians, cyclists, commuters, tourists, residents and vehicles.

Anderson said the landscape would have to be created on the deck of the park. There will structural questions, such as where to put columns and how the deck will be supported. There are 10 to 12 rails underneath the deck.

"We're used to working with landscapes that already exist. Here we're kind of creating our own deck, which is our landscape that we are going to program," he said. "The structure and the program really have to be thought through together for this project."

He said the park needs a lot of green open space and community amenities, while Renaud wants a place that can be used in all seasons.

Renaud said one of the biggest challenges is not imaging how it could look like but "reeling that in." Ideas still need to be down to earth, she said.

"We can do anything," she said.