The classic 1,400-square-foot apartment at the top of a 1920s building on leafy Pierrepont Street had never been renovated in its long life. The thick plaster walls had panel molding typical of its day, and the floors were herringbone parquet. It had four exposures and, consequently, plenty of light. Sounds good on paper? Perhaps, but those walls defined rooms too small for today's tastes and for the needs of the new homeowners' growing family, leading to a total gut renovation of the space.