The Renaissance Boston Waterfront Hotel, the first Renaissance property in downtown Boston, opens this week. The $165 million hotel project is the next chapter in the fast-paced development story of the South Boston Waterfront’s Seaport District. It has 471 guestrooms, including 21 suites, and features over 21,000 sq. ft. of flexible meeting space, with a 10,700-square-foot ballroom and a 4,400-square-foot junior ballroom that are conveniently located on the same floor.