The term "substantial room" is a correct and usable phrase in written English.
It is usually used to describe a significant amount of space or capacity for something, either physical or figurative. For example: "The project budget provides substantial room for negotiation."
"There is substantial room for improvement".
It was surely Corbyn's best big performance to date, but there is substantial room for improvement.
It still has substantial room for error and a lot of room to grow.
But Mr. DeMeo and others said that wind energy had substantial room to grow before storage became necessary.
Each floor had one substantial room, together with a sort of closet at the back and a linking staircase.
All told, the system leaves "substantial room for human error, as well as possible willful misrepresentation," according to the audit.
Dr. James J. Mongan, the chief executive of Partners HealthCare System, a big medical network in Boston, agrees that "there's substantial room for improvement".
He is very happy with his implants, he says, "but I think there is substantial room for improvement that has not yet been fully realised".
One of the show's largest pieces, "Divine Violence," by Daniel Joseph Martinez, fills a substantial room with hundreds of gilded plaques carrying the names of what Mr. Martinez labels terrorist organizations, from Al Qaeda to tiny nationalist and religious groups.
There is substantial room for interpretation, legal experts said, between Common Article 3's strict prohibition of, for instance, humiliating treatment and the McCain amendment's ban only on conduct that "shocks the conscience".
And liberal delegates who signed onto the deal noted that the guidelines were broad enough to leave substantial room for debate over just what Islamic law should require in the context of modern Egypt.
