Please share your reasoning in the comments, especially how you would approach the issue from an existing-building / historical compliance perspective and which Code provisions you would rely on.
I’d be interested to see how different architects, engineers, code consultants, and building officials would approach this situation.
A 70 years old one-storey unsprinklered school building must be sprinklered under the current Code if its building area exceeds 2,400 m²
a) true
b) false