Within a body of text, “guest rooms” and “suites” should be written in lowercase (unless at the beginning of a sentence), if referred to generally. If you’re writing about a particular type of accommodations, use title case. “Guest room” should always be written as two separate words. Never abbreviate either word.
Book elegant guest rooms and suites at Hilton San Francisco Union Square. Enjoy spectacular sunsets in a Skyline Bay View Room, or upgrade to a Skyline Bay View Suite for extra space and amenities.