The country’s largest retail property firm announced plans to upgrade and expand its portfolio of shopping, dining and mixed-use destinations with a $1B investment in both 2017 and 2018.

Simon Property Group has invested more than $5B into developing its portfolio in the past five years, and the REIT plans to continue the upgrades by adding gathering places at its centers and doing interior upgrades. The REIT also plans to add restaurants, luxury retailers and hotels to its malls to fill space vacated by Sears and other anchors.

"Our primary focus continues to be investments in our physical product to enhance our guests' experience," said Simon Property Group chairman and CEO David Simon at the RECon Global Retail Real Estate Convention in Las Vegas. "Nothing is more important to us.”

Simon will finish renovating its world-famous Houston Galleria at the end of the year, and plans to open 35 new stores and restaurants in a former Saks Fifth Avenue space this fall.