The Civic is not the only hospital that needs more land.

     "The Ottawa Hospital (TOH) has developed a Master Plan, which provides options and scenarios for the future expansion and/or redevelopment of the Civic, General and Riverside Campuses." (Memo from Mr. Cameron Love, VP Facilities, Planning and Support Services-Land Planning Matrix, May 28, 2007---Google "Untitled Greenspace Alliance of Canada's Capital".)
The main reason why the Sir John Carling Site is the preferred location for a new Civic:
Future Expansion
"Flexibility for future expansion over and above what is currently planned."
Eight possible land options in the year 2007:
1.) NCC Options
(a)  Experimental Farm - Across from Existing Civic.
(b)  Experimental Farm - Across from Nepean Sportsplex.
(c)  Experimental Farm - Baseline and Fisher (Cross Road).
(d)  Experimental Farm - Sir John Carling Building.
(e)  Hurdman Station.
2.)  Bayview Yards - Adjacent to LeBreon Flats.
3.)  Woodroffe at Baseline - Beside Algonquin College.
4.)  Nortel Site - Carling at Moodie.
5.)  Confederation Heights - Riverside/Heron; Canada Post.
6.)  Tunney's Pasture.
7.)  Booth Street.
8.)  Hunt Club South Corner.

The Faircrest Heights Community Association in Alta Vista, Ottawa contacted local, provincial and federal politicians and prevented the sale of the National Defence Medical Centre property to developers.

NDMC - 1983.

NDMC - 2005.