An eave--a recessed niche carved into your wall--is the perfect location for a bookshelf. Eaves are designed for storing items, and bookshelves allow you to store more items in a confined space. By building a bookshelf within an eave, you can avoid having the bookshelf eat up valuable floor space, and you can keep your look classy by storing antique collector's books or decorative items on the shelves.
Check the eave for studs by either using a stud finder--a device available at hardware stores that indicates stud locations--or by tapping on the wall gently with your fist. You'll hear a different, deeper sound where the studs are located.
Only hang a shelf where studs are located, as the studs are necessary for holding the weight of the shelf and the items on it.
Measure the distance across the eave where you want the shelves to hang. Note that many eaves are not equally spaced in all parts. Some eaves narrow at the top, so measure the distance at each desired shelf location.
Mark a line where you want each shelf to sit. Check the line with a level to make sure it's even and flat. Ensure that you accurately mark the desired shelf position on the wall to correspond with the studs. The shelf itself will sit just on top of the stud, while the L bracket that holds the shelf in place (discussed in steps 9 and 10) will be screwed into the stud.
Mark the corresponding distances from steps 2 and 3 in pencil on wood planks. Add an additional 1/8 inch in width on both sides, which is the approximate amount of wood that will be lost when the saw blade makes the cut.
Wear safety goggles.
Cut the wood planks on the marked line with a circular saw.
Dry-fit the shelves into their desired locations by holding them and seeing if they fit. Make any additional cuts if necessary.
Paint the wood planks a desired colour, or brush them with wood stain if you prefer.
Screw L-brackets to the bottoms of the wood planks.
L-brackets can be bought at your local hardware store. They are intended to brace the shelves to the wall by holding the bottom of the shelf with one side of the "L" and attaching the other side of the "L" to the wall. It's easiest to screw the L-bracket to the wood plank first, then screw the other side of the "L" into the eave.
Place the shelves into the eave and secure them in place by screwing the other side of the "L" into the eave with a cordless drill. Ensure that the side of the "L" that you're screwing into the wall is driven directly into a stud.
Always use extreme caution when operating a saw and/or a drill. Never allow children near a saw or drill. Do not allow teenagers to use a saw unsupervised. Always wear appropriate safety equipment, and take proper safety precautions before, during and after working with sharp objects.