If you're planning to remodel your home or office building, or you want to find a job in interior design or architecture, you're going to have to know how to read floor plan symbols. The good thing is that once you know how to read one set, you know how to read them all. The bad thing is that they are not always intuitive, and floor plans do not always contain keys to what the symbols mean.
Look for the scale. All floor plans should have one. It denotes how the sizes on the diagram translate to sizes in real life. The scale is typically a long, slim rectangle with distances in feet noted above it, as on the legend of a map. The north arrow (large arrow with an N in it) lets you orient your floor plan.
Look for wall symbols. They're long, thin rectangles, and come in two types. The first, shaded in a solid colour, denotes a solid wall that extends floor to ceiling. A transparent rectangle denotes a wall that extends only partway to the ceiling, such as the bottom of a breakfast bar.
Look for symbols denoting doors and windows. Doors are represented with a half arc that extends in the direction in which the door opens. (See image). French doors are represented by two arcs next to each other. Bi-fold doors are represented with upside down V shapes instead of arcs to indicate that they fold at an angle. Windows are represented by a thin line between two wall rectangles.
Know the bathroom symbols. The symbols for sink, bathtub and toilet are easy. They look like those fixtures as viewed from above, complete with faucets, if applicable. The symbol for a shower is a little trickier: It's a box with an X across it. (See image).
Know the kitchen and laundry room symbols. Like bathroom symbols, these look like the items they represent. The kitchen sink, refrigerator and stove look like those appliances viewed from above. The same goes for the washer and the dryer.
Not all design firms use exactly the same symbols, but they should be similar enough so you'll get the idea.