"Is it our room?"
Translation:Est-ce notre chambre ?
No, the rule: [he/she/it + is + modified noun = c'est un/une + noun] is also valid in the interrogative and negative modes:
it is our room = c'est notre chambre
is it our room? = est-ce notre chambre ?
it is not room = ce n'est pas notre chambre
is it not our room? = n'est-ce pas notre chambre ?
You may have noticed how Duo can be binary. So, every translation should be back-translatable to the original sentence, in meaning of course, but also in style, register of speech, etc.
"the room, is it ours?" is what you get when you back translate your version, and it is another (more emphatic) way of asking the question.
However, in real life, what you suggest works, although it would be better with "cette" instead of "la". There is a kind of incompatibility between something specific and unique "la chambre" and a possessive pronoun. With "la chambre", you can identify it as "elle est à nous".