A submission paper presented to the government in July last year, obtained by the the Canberra Liberals through freedom of information, said about $109 million over five years was needed to avoid further deterioration of ailing assets.

The submission was created by senator elect Katy Gallagher - when she was working for Calvary last year - and Dr John Merchant.

The Opposition's spokeswoman for health Vicki Dunne said the documents showed the government's pledge for Calvary Hospital was a fraction of what was needed.

Health Minister Meegan Fitzharris on Wednesday announced $40 million over four years in funding for Calvary, in a pre-budget announcement.

The funding would increase the number of operating theatres and expand the capacity of the emergency department.

It would allow for 81 new staff members over two years, including 46 staff in the new expanded emergency department once complete.

Ms Fitzharris said the funding would expand Calvary's capacity to perform elective surgery and allow more urology services to be completed.

But according to the submission paper, Calvary's strategic asset management plan indicates $109 million in combined recurrent and capital investment over five years was required to address condition and functionality performance gaps and avoid further deterioration of the buildings.

It said three quarters of critical and high priority buildings at Calvary public had condition ratings below the target rating.

"What I take out of this announcement today is that this is a band-aid," Mrs Dunne said.

"It looks like they're doing something for Calvary but they haven't looked at the underlying important issues about the quality of the infrastructure and the life expectancy of the infrastructure at Calvary."

Ms Fitzharris said she was aware of the need to continue to upgrade hospital facilities across the territory.

She said the $40 million in next week's budget came on top of the $15 million for capital upgrades in last year's budget.

"In addition, in May 2018 I announced with the Chair of Little Company of Mary, John Watkins that ACT Health and Calvary Public Hospital had begun planning for a shared future that ensures health care services on the northside are modern, integrated and meeting the needs of our growing community," Ms Fitzharris said.

"We know Canberra's north is rapidly growing, so to future-proof our healthcare system we are looking at how we can better deliver health services so Canberrans receive high quality healthcare where and when they need it.

"This is in stark contrast to the Canberra Liberals who have no new plans or ideas to improve the healthcare of Canberrans."