WHEN MIKE and Linda McCarthy decided to enclose their side porch, they wanted a distinctive library -- a room off the living room that would have light, air and a certain flair, something that would give the room a personality and make it more than just an extension of the existing space.

The architects, Calvert Bowie and Bill Gridley, wanted to honor the 1905 architecture of the house, but at the same time they wanted to give it a 1980s touch. The solution was to enclose the exterior in the same patterned shingles as the rest of the house, but to build in a hint of the newness inside. Hence, at the corners of the addition, where the porch columns once stood alone, there are fixed-glass windows that butt against one another -- glass to glass -- so that the corners virtually disappear.

Inside, the ceiling soars a story and a half and is sculpted in a star- shaped pattern. The built-in mahogany shelves are set in the wall that is shared with the living room. Dramatic interior columns have been added to break up the space.

The flooring is stained dark in a rich herringbone pattern of mahogany and cherry. To give the room an old-fashioned final touch, the walls are papered deep green.