St George's Hospital Trust Board have agreed plans to develop a private patients' wing.
A panel of trustees made the decision during a meeting last month, with plans to create 40 beds, two operating theatres and an outpatients department.
The private patients wing would be located next to the Atkinson Morley Wing in an area currently used for parking.
Consultants Ernst and Young said the trust must "revisit assumptions for private patient growth."
Ingleby House, currently used for staff accommodation, is being proposed to be used as a patient hotel.
The meeting also heard the number of complaints at the hospital is up by seven per cent, while the vacancy rate is at 10 per cent.
Minutes from the meeting show there were breaches of the four hour turnaround in the Accident and Emergency department in November and December, with the target figure of 95 per cent not being met.