A Highland hospital needs "considerable work" to bring it up to standard, according to the health board.
The backlog of maintenance required at Lawson Memorial Hospital in Golspie runs to £3.3m.
NHS Highland said £1.85m would have to be spent within the next five years at the 111-year-old hospital.
Flat roof buildings on the site were the cause for most concern for the board, which said any changes would not mean a reduction in beds or services.
The site provides inpatient and outreach rehabilitation services in the 20-year-old Cambusavie Unit building and a GP-led inpatient unit in the hospital.
Other services include a minor injuries service, x-ray, out-of-hours medical service, general outpatients, day case and day surgery.
Locality General Manager, Georgia Haire, said recent surveys of the site had shown that some buildings were in need of considerable work, much of which was associated with a number of flat roof areas.
She said: "The current backlog for maintenance at the Lawson is £3.3m, £1.85 million of which is likely to be needed within the next five years.
"We will be looking at options to improve the estate and the efficiency of our services whilst ensuring that all existing services on the site are maintained and enhanced where possible.
"We will be involving staff and the local community in the work."
The hospital was opened in 1900.
It hit the headlines in 1969 when it treated the Beatles' John Lennon.
The star, then at the height of his fame, was on holiday with his wife and their children when they had a car accident near Loch Eriboll.
Lennon received 17 stitches for facial injuries while Yoko Ono received 14 stitches in her forehead.
Following a five-day stay at the Lawson Memorial, Lennon told reporters: "If you're going to have a car crash, try to arrange for it to happen in the Highlands. The hospital there was just great."