Windows from derelict 10-storey tower blocks set for demolition are to be salvaged and used in the renovation of an old eastern European hospital.
The Hazel Court flats have been on Swansea's skyline since 1962
Normally builders would take just minutes to rip out each of the 100 UPV panes at Hazel Court in Swansea.
Instead they will be carefully removed and donated to Swansea-based charity To Russia With Love, which is building a rehabilitation centre in Belarus.
The flats, which have been empty for a year, will then be demolished.
The charity has been sending aid to Belarus for 10 years, and is setting up the rehabilitation centre for alcoholics with its sister church in the former Soviet republic.
The windows, worth £10,000, will make a big difference as by the time they get there temperatures could have dropped to around minus 10 degrees C.
The demolition work is being carried out by the Cuddy Group, whose managing director Mike Cuddy said the firm would cover the additional labour costs of removing the windows, adding about two weeks onto the job.
Carefully does it: the windows will be removed delicately
"It's rare for a demolition job to open up such an obvious opportunity for us to assist a worthy cause," he added.
Charity spokesman Mike Lewis said: "I am a regular at the local church in Sketty which is overlooked by Hazel Court flats.
"When I heard they were being torn down I jumped at the chance of getting hold of the windows.
"This will make a big difference to what we can achieve within our renovation budget."
Hazel Court was built in 1962 and run as a sheltered housing complex by Swansea Council, but the last residents left last year.
Once the windows have been removed the flats will be torn down using heavy machinery rather than explosives.