The housing market is hot right now, and that includes Philadelphia and the suburbs. We wanted to find out where there's high demand and low demand, where the hottest places to buy and sell a house are right now, and even if there are any bubble concerns in the market - so we called Maria Quattrone, CEO and founder of Maria Quattrone & Associates at RE/MAX @ Home in Center City. Quattrone joins KYW Newsradio In Depth to break down what the Home Demand Index is and why some of the craziness in the housing market can be traced back to the Great Recession more than a decade ago.