My wife wanted somewhere to store her spices so they wouldn't be all piled up in a cabinet. Since I'm fond of "secret compartments", I decided to build some shelves in a cavity of the kitchen wall and build a door that would double as a picture frame. The shallow depth of the wall cavity helps keep everything in front where it can be easily seen.
**Before you finalize a location, determine if there will be any electric lines, plumbing, heater ducts, or any other obstruction that may pass through the wall cavity that you'll be working in. This cabinet will fill the entire depth of the wall cavity.
There's no set way to do this. It will vary from house to house. Here's a couple guidelines to help determine if its a safe location.
Some of the commercial stud finders also have a non-contact voltage detector built into them. You can also look lower on the wall to see if there are any outlets close by. Wires typically run horizontally through the studs from one outlet to the next, but sometimes the wires will be fastened to the studs to run vertically either up to the attic, down to the basement, or even over doorways.
Ductwork will always run parallel between the studs (or between floor joists). If ductwork runs perpendicular to the studs or floor joists, it will be outside the studs or under the joists. Look for any heat registers nearby. They can be in the wall, ceiling, or floor. In a multi-story home, you also need to be aware of any vents that may be in the same general location on the floor above you.
Again, be aware of your location. If you're in a family room and don't have a bathroom or kitchen in close proximity you're probably safe. If there's a sink directly above you up stairs, you may want to investigate some more.
Step 1: General Info
There are a few things to consider before starting this project.
First: You'll need to locate the wall studs. There are commercially available stud finders, but I decided to use a strong magnet and a string. The magnet will stick to the nails (or screws) that hold the drywall (or other wall covering) to the studs. The nails are typically spaced ~18" apart (going up and down the stud). I tape a string to the magnet and dangle the magnet so it is touching the wall. I'll drag the magnet side to side until it sticks to a nail. From that point, you can easily pinpoint the rest of the studs. Typical stud spacing is 16" from the center of one stud to the center of the next stud. Use a tape measure to get approximate stud locations and verify with the magnet. Once you find the studs, you can determine how high you want the cabinet and how tall you want the cabinet. Since the 16" O.C. (on-center) is a standard for most buildings, the width of the cabinet is limited to ~14.5".
Another thing to consider is whether you want a door covering the cabinet shelves. If not, you can build this a little bit deeper and build a face frame on the outside of the wall. Of course, if your house is built with 2x6 studs, then your cabinet can be made even deeper.