How to Build a Built-In Bookcase

To determine your bookcase’s height, measure the height of the wall where you’ll install it. Measure from the floor to the base of the crown moulding. Take that number and subtract 1 inch for your bookcase height. Most functional built-in bookshelves average 72 to 80 inches tall.

Measure the width of the wall where the bookcase will go. If your bookcase will be on a wall that includes windows or doors, subtract the width of those windows or doors — including any trim — from your measurement. Subtract an additional 2 inches to accommodate the thickness of the side panels and trim that’ll be part of the bookcase.

Decide how deep the bookcase will be. Most are 12 inches deep, but you can customize this if you have large books. We’ll use the standard 12 inches in this example.

Measure the area of your room and then sketch a diagram that includes your bookshelf. Be sure to add your furniture to the sketch. Will the room feel cramped with the addition of a built-in bookcase? Can you open the door fully without hitting the bookcase? Will it block your view in any way? If so, now is the time to make adjustments.

Move furniture out of the way and lay down a drop cloth to protect your floor. Using a utility knife, cut the seal off the baseboards and moulding. Remove them carefully. Do the same with chair railing and wainscoting.

If the weather allows, cut the wood outdoors or in the garage to reduce sawdust inside. Using your saw horses and a circular saw, cut the plywood for the back of your built-in bookcase to your height and width measurements. Set aside.

Cut two pieces of 1-inch-by-12-inch lumber to the vertical measurements for your side panels. Next, cut the number of horizontal shelves you want from your 1-inch-by-12-inch lumber. Finally, cut two pieces of 1-inch-by-2-inch lumber to the vertical measurements for your vertical faceplates.

Subtract 1-1/2 inches from your horizontal measurements to create the faceplates for the shelves. Cut the number you need from the 1-inch-by-12-inch lumber.

Place vertical pieces side by side so you can mark them uniformly. Make a mark at the top that’s 1 inch below the height of the crown moulding. This is where the new crown moulding will rest on the side panels. Next, make a mark 1 inch above where the top of the baseboard will rest on the front edges.

Place a tape measure on the vertical boards and mark the placement of your shelves. Use a square to draw level lines across the front of the boards at each mark.

Align the bottom horizontal shelf with the bottom of a vertical side panel. Apply wood glue to one end of the shelf and press it against the inside face of the vertical piece. Use a nail gun to secure the shelf. Do the same with the other shelves, aligning them to the shelf marks on the vertical panel and securing them with wood glue and a nail gun. Repeat this on the other side with the other vertical sidepiece.

Ensuring the bookcase is facedown, apply wood glue to the edges of the shelves and vertical pieces on the backside of the bookcase. Place the cut piece of plywood on the back of the shelving unit.

Use a square and draw lines on the plywood identifying the horizontal shelves and a nail gun to secure the plywood to the horizontal and vertical pieces. Turn the bookcase over.

Using wood glue, attach the pieces of 1-inch-by-2-inch lumber to the front edges of the vertical sidepieces. Secure with a nail gun. In the same way, attach the faceplates to the horizontal shelves.

Using a stud finder, find and measure the studs on the wall where you’ll attach the bookcase. Lift the bookcase and slide it into place and then transfer the measurements for the studs to your bookcase. Secure the shelf to the wall studs with screws.

Reinstall the trim pieces so they blend in with the existing moulding and baseboard. You can also use new matching pieces of moulding. Secure with a nail gun and, if needed, secure a piece of 1-inch-by-2-inch lumber vertically to fit between the crown moulding, baseboard or wainscotting for a finished look.

Fill in screw holes and nail holes with wood putty. Let dry and sand before applying paint or stain.

Remove the drop cloth and return your furniture to the room.