John Daugherty Jr. says there are plenty of positive signs that the luxury housing market is turning around. Inventory is low, new construction is on the rise, and the agents that work for his high-end realty firm have exceeded their sales goals almost every month for the last five. He’s now concerned that Houston will have a major shortage in new construction by the end of the year. As his company enters its 44th year, Daugherty spoke with Chron.com real estate reporter Nancy Sarnoff about what he thinks the future holds for Houston’s high-end housing market.