"An Act to amend the National Capital Act (buildings or works of national significance)" will stop a hospital from occupying the Farm.

Senator Serge Joyal recently introduced the Bill to the Senate:
     "It would apply to both building and demolition within several hundred metres of the Hill and other national historic sites." (From: Senator wants NCC to have power to limit development near Parliament" by Tom Spears, Ottawa Citizen, December 13, 2019.)
Bill S-203 could be amended to include all of the endangered heritage buildings and landscapes in the National Capital. Right now the bill applies to the Parliamentary Precinct:
     "The objective of the bill is to "prevent demolition, restoration, addition, and destruction that would change the immediate vicinity of Parliament Hill." (December  2019 comment by Senator Serge Joyal to CBC News.)
The Central Experimental Farm is a National Historic Site and the hospital will be located metres away from the Dominion Observatory campus and the William Saunders Building.
The Dominion Astrophysical Observatory, South Azimuth and Photo Equatorial buildings are Classified Federal Heritage Buildings.
The William Saunders building is a Recognized Federal Heritage Building.

The National Capital Commission, Agriculture Canada and Public Services and Procurement Canada gave the health care facility all of the land within the purple lines. This photo of the CEF is from the Ottawa Citizen.

The bill was created in response to an attempt to construct a modern addition to the Chateau Laurier Hotel, which is located in the Parliamentary Precinct.
SENATE OF CANADA BILLS - 203
An Act to amend the National Capital Act (buildings or works of national significance.)
  First Reading December 10, 2019.
(1)  Section 2 of the National Capital Act is amended by adding the following in alphabetical order:
building or work of national significance means
...
...
(j) any place that has been commemorated as a historic place under paragraph 3(a) of the Historic Sites and Monuments Act.
(k) a national historic site as defined in subsection 2 (1) of the Parks Canada Agency Act;
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An amended Bill S-203 will stop any redevelopment of the Sir John Carling Site (except by Agriculture Canada officials who want to create a visitor's centre and a museum in the Sir John Carling Building cafeteria annex.)
 An amended  bill will also veto construction of condominiums on a nearby park and a parking lot. The Rideau Canal is a UNESCO World Heritage Site and a National Historic Site and bill specifies that a 500 metre buffer zone will separate new developments from Parks Canada designated properties.

The map is from Google Maps.

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In the year 1998 the Central Experimental Farm located at 960 Carling Avenue in Ottawa, Ontario (River Ward) became a National Historic Site of Canada, designated by the Historic Sites and Monuments Board: