Local real estate developer Peter Allen laid out a vision for the future of downtown Ann Arbor today — not specifically what he thinks should be built, but how the city and the Downtown Development Authority might go about creating the vibrant setting they desire. Allen talked at length about possibilities for the Library Block, an area bounded by Liberty, William, Fifth and Division. He thinks it's easily capable of welcoming 500,000 square feet of new development, and possibly as much as 1 million square feet — whether that's retail, office, residential or something else. "We're talking about thousands of residential units potentially," he said. "We're talking about hundreds of thousands of square feet of office potentially." Read the story.