"To raise the ceiling" means to increase the maximum limit or threshold, often referring to an upper boundary or restriction that is being lifted or expanded. Full definition
This is the first time in nearly thirty years that researchers have raised the ceiling on yields of rice, the grain that feeds half the world's population. (newscientist.com)
By raising the ceiling height, the team created enough vertical space to carve out an overhead loft that can sleep up to four more people. (coastalliving.com)
In a standard height room, this will help raise the ceiling in your room, providing you with added drama and a professional decorating touch! (devinedecoratingresults.com)