Located at 6677 Sea Harbor Dr., the 781-room resort lies directly across the street from SeaWorld's main theme park entrance.
The company filed a change determination request on Thursday with Orange County for the Development Plan to add 41,731 square feet of new meeting space on the southern end of the hotel, to cover what is now 72 surface parking spaces.
This would boost the hotel's available convention space from 106,020 square feet to 147,751 square feet, a total that would rank the Renaissance 11th among Orlando-area resorts in terms of available event space.
Officials with Sunstone did not respond to calls for comment on Friday.
Sunstone's investment in more meeting space is part of a trend for local hotel owners in recent years as they see the business "groups market" recover following the recession.
The Doubletree by Hilton Orlando at SeaWorld has had 30,000 square feet of new event space added over the past two years as part of a new owner's $30 million renovation investment.
"Hoteliers in Orlando like the group markets because their average spend per guest per day is higher than almost any other market segment," said Paul Sexton, vice president of HREC Investment Advisors, a national brokerage offering consulting, development and asset management services to the hotel industry.
"A lot of people view Orlando as a lower-rated market, and that is true for certain segments of the market," he continued. "But the real story is that because of our groups-oriented hotels, we also have one of the finest collections of luxury hotels of any market in the nation," noting the Ritz Carlton, Waldorf Astoria, Four Seasons, Hyatt Regency, Gaylord Palms, Loews properties, the Omni Orlando and more.
Sunstone owns 27 hotel assets around the country totaling more than 13,200 rooms, with the Renaissance Orlando its lone property in Florida, having paid more than $29.7 million in 2008.
Its Orlando hotel produces a 7.2 percent EBITDA (earnings before interest, taxes, depreciation and amortization), according to a Sunstone presentation to investors from late 2016.
The last significant investment in the property was a $35 million renovation that spanned 2006 to 2011, which included meeting space revitalization, 65 suite upgrades, an expansion of the pool area and an added 8,000-square-foot function lawn.
The hotel's DP was last amended in 1989, then known as the Stouffer Resort, when 4.15 acres were added in order to build 36,000 square feet of convention space and 70,020 square feet of support/operations space.