Reliable Source: Penthouse designed by Library of Congress architect on the market

A Kalorama penthouse apartment is a posh piece of D.C. real estate.A Kalorama penthouse designed by one of D.C.'s most renowned architects is more attractive still.The two-bedroom condo at 2201 Mass. Ave, NW, part of a larger mansion called the "Argyle House" originally designed by the Library of Congress architect, Paul J. Pelz, went on the market Friday.