Temporary wards are to be built at two hospitals in south Wales to help deal with pressures on beds.
The two wards, expected to cost more than £7m, will create up to 60 new beds at Morriston Hospital in Swansea and Bridgend's Princess of Wales Hospital.
Abertawe Bro Morgannwg University Health Board (ABMU) said the wards would be a "considerable help" to deal with winter pressures.
They will also be used to minimise disruption during improvement works.
Work is expected to begin later this year, with the temporary beds ready by 2018.
Sian Harrop-Griffiths, ABMU's director of strategy, said many of the wards at the two hospitals needed to be upgraded to "meet modern requirements", including better disabled access.
"It's difficult to do this work when the wards are in full use, so having an alternative ward for patients to go will be extremely helpful," she said.
"These new units will also be a considerable help at times of high pressure, as they will offer additional bed space when we need it most."
Plans for the unit at the Princess of Wales Hospital, which will see the demolition of the hospital's record building and loss of part of the car park, have been approved by Bridgend council.
Plans for the two-storey unit at Morriston and the creation of a 469-space temporary car park have been submitted to Swansea council.