In this space-starved city, spare rooms are not easy to come by, and many New Yorkers (parents in particular) may find themselves considering an apartment with one windowless bedroom. Yet, for a room to legally be called a bedroom it must have a window, so oftentimes windowless "bedrooms" will show up in listings as "home offices." These home office situations are particularly common in apartment buildings that were once office towers (hence their prevalence in the Financial District).

As a rule, a windowless room is worth about half as much as a legal bedroom of the same size. Without a window, ventilation may be a problem, though an HVAC unit or a vent that's part of the building's fresh air exhaust/air exchange system can sometimes help. Also, technically, using one as a bedroom violates both building and fire codes. Though chances are you won't ever get caught, putting a bed or a crib in a room doesn't make it a bedroom in the eyes of future buyers.

For more, read "Is it okay to put a kid in a windowless 'bedroom'?"