The blaze broke out at the premises in the Whitecross area of Raphoe sometime after 8pm.
A number of units of the Fire Service from both Donegal and Derry battled the fire for a number of hours before it was finally brought under control.
Fortunately, there are no reports of injuries.
The cause of the fire has yet to be established.
Gardaí confirmed they were in attendance and that the fire was extinguished by local fire services.
“No injuries were reported and no offences were disclosed,” a garda spokesperson said.