While still the Chairman of Glazer Steel Corporation, Guilford entered the real estate development business in Knoxville. The first building that Glazer developed was Shelbourne Towers near the University of Tennessee campus in Knoxville, described as Knoxville's "first high-rise apartment building". His entry into the real estate development business occurred in 1951, when the U.S. Atomic Energy Commission selected a company headed by Glazer to build a shopping center in Oak Ridge, Tennessee. A shortage of steel resulting from the Korean War delayed construction, but the center opened in 1955. In 1960, Glazer moved to the Los Angeles metropolitan area, where in the 1970s he developed the Del Amo Fashion Center, which was at one time the world's largest shopping mall. His company was also involved in shopping center development throughout the United States. He later sold off most of his real estate holdings. The Del Amo Fashion Center was sold to the Mills Corporation in 2003.