For over 50 years the Duell family has owned and managed buildings all over Manhattan. Additionally they manage other owner's buildings as well. Much of their portfolio of managed buildings are either rent-stabilized units or relatively small buildings, however, they are all taken care of extremely well and meticulously. Concentrating mostly on the downtown market, this 57th Street based real estate firm is a prime example of an entrenched New York City landlord with no plans of selling any time soon. This landlord's website is updated daily.