The Houston Galleria plans to add a 30-story tower housing a luxury hotel and 75 to 100 condos. The mammoth mixed-use center already has two Westin hotels.

“There is significant demand for a luxury hotel,” said David Contis, president of Simon malls and executive vice president of Simon Property Group. “It’s a differentiator. Hotels in the area are good, but this will be luxury or ultraluxury.”

The company hasn’t selected the architect or hotel operator but aims to break ground in mid-2017 and open the project roughly two years later.

Long the city’s dominant mall, the Galleria recorded $1.2 billion in sales last year, Contis said. Growth may be hampered this year by numerous bankruptcies and thousands of layoffs in the oil business.

“Houston has been hit a little, but the Galleria has been relatively stable,” Contis asserted. “Sales are probably flat to up slightly, but it’s early in the year, so who knows?”

The mall is in the midst of a renovation and expansion that includes a newly constructed 200,000-square-foot Saks flagship set to open on April 27. Construction will begin in May to convert the existing Saks store into 40 or 50 boutiques by next spring, Contis explained.

In addition, The Webster debuted Jan. 1 in a new freestanding building, and Christian Louboutin, Céline and Yauatcha dim sum teahouse are due to open this year.

Renovation of the luxury wing between Neiman Marcus and Saks is well under way with the installation of white marble, porcelain and black granite floors, LED lighting and soft seating areas. It will be completed by October, Contis said.

Simon officials previously said the renovation and retail expansion represented a $250 million investment, but Contis declined to comment on that figure.