Vistra’s Las Colinas campus is up for grabs Energy company headquarters is listed for sale by New York landlord. Vistra's Irving headquarters fronts on Bush Turnpike.(JLL) A Las Colinas headquarters is up for grabs. The Irving office campus houses the headquarters for utility firm Vistra Corp. The almost 250,000-square-foot office property at 6555 Sierra Drive was built in 1999 and is owned by a joint venture that includes New York-based Lexington Realty Trust. The building, which faces the Bush Turnpike, is fully leased to Vistra through 2035. Commercial property firm JLL’s Jack Crews, Coler Yoakam and Maggie Hood are marketing the building for sale.