Century 21 is one of the most recognizable real estate brands in the country. Yet compared with brokers like Long & Foster, the firm once known for its agents in mustard-yellow jackets has a small presence in the Washington area. The company’s local offices are franchises, independently owned and operated but supported by the New Jersey-based company. Last week, Century 21 Redwood Realty, a franchisee with offices in Ashburn and Arlington, celebrated a new office in Dupont Circle. I sat down with one of the founders of Redwood, Nicholas Pasquini, to find out why, in the middle of one of the worst periods in the housing industry, his company is expanding. Century 21 chief executive Rick Davidson was in town for the event and also to lobby Congress for changes to housing policy.