Dozens of people attended a meeting about re-zoning for the new Civic campus of the Ottawa Hospital on Monday night, including several residents who say they're worried the full environmental impact of the project is still unknown.

The city hosted a public information session about the facility that will eventually be constructed at the former Sir John Carling Building near Dow's Lake.

"This is the first step in a long planning process for the new hospital," said Jean-Charles Renaud, a planner for the City of Ottawa.

Members of the public were invited to share their thoughts on the impact of this new hospital.

"One of the biggest concerns is losing our urban green space. It's a gem," Sharanne Paquette said.

With the environmental assessment yet to be carried out, some local residents worry about the project moving forward without knowing the full details.

This 20-hectare plot of land will eventually house the new Civic Campus of the Ottawa Hospital, but part of the area still needs to be re-zoned. (National Capital Commission)

"We need to know what the environmental implications will be up front, then we zone it to make it work, not the other way around," Rosalind Paciga said.

The city councillor for the area, Riley Brockington, said five hectares of the site has to be re-zoned, but the rest of the 20-hectare lot is currently zoned for a hospital.

"Building a new hospital doesn't happen that often, this is going to be a major project," he said. "It may not be the perfect site for all people, but at the end of the day this is where the hospital is going."

Designs for the hospital will be completed in five years, and construction will take another five years. Public consultation meetings will be held throughout the process.