Johns Manville inked a lease deal for 118,865 square feet of office space at 717 17th St. and will remain as the anchor for the plaza which bears its name. Johns Manville which is owned by Warren Buffet’s Berkshire Hathaway will continue to operate its 325,000 square foot technical center in southwest Denver.  Crescent, owns the 29-story, 737,431 square foot office building which was built in 1978 is currently undergoing major renovations to lobby and other improvements to the plaza.