Central Scotland Police said the thieves got away with kit worth thousands during the audacious raid on a yard used by Stirling Council.
The locked site on the A81 Glasgow-Aberfoyle Road in Dumgoyne is used mainly during the winter months by the council’s roads department to allow them to carry out highways maintenance.
Police said the secure gates had been broken and units taken which would have required a large vehicle with a mounted crane to lift and remove.
The stolen items were a portable toilet and a metal site hut measuring 20 foot long, 10 foot wide and 8 foot tall.
It is made by Sibcas, is white with blue legs, has steel shutters on doors and windows, and contained office equipment
Constable Mark Harvey said; “Although in a quiet area, a large ‘Hiab’ style vehicle would have been required to lift these items and we feel certain that people would have seen them being removed.”