DIY Rigid Foam Shutters

Measure the length and width of the inside of the window frame. Subtract three-quarters to 1 inch from the width depending on the size of the hinges you select.

Cut a piece of 3/4-inch rigid foam insulation to the dimensions from Step 1 using a utility knife. Mark the vertical center of the piece of foam and cut it into two pieces along that line to form the individual shutters.

Cut eight pieces of rabbeted narrow wood molding at a 45 degree angle the length of the shutters, using a miter saw. Cut eight pieces of molding to match the width.

Lay four pieces of molding face down on a table to form a rectangular shape. Run a bead of carpenter’s glue along the rabbeted portion on the back of the molding. Set a piece of foam board insulation inside the molding’s rabbeted edge. Apply carpenter’s glue to the rabbeted edge of the remaining pieces of molding. Set them in place, face up, around the perimeter of the insulation board. Clamp the wooden pieces with the insulation sandwiched between them together with wood clamps.

Attach the corners to each other with finishing nails. The nails should be long enough to penetrate through one piece of molding and into the other without protruding from the second piece of wood.

Place at least three finishing nails along all sides to connect the front pieces of molding with the back. The nails should not totally penetrate the back of the shutters.

Repeat Steps 4 to 6 to build the other shutter.

Paint the insulation shutters the color you desire. Allow the paint to dry before applying a second coat. Let it dry before proceeding.

Attach two hinges to the outside edges of each of the shutters using screws from the assembly kit. Predrill the holes to make it easier to attach the hinges to the wood.

Lay the shutters side by side on a flat surface with the top and bottom edges even and the top side facing up. Set the center latch and catch in place. Attach them with screws from their assembly kit.

Hold the shutters in the window so the two center edges match and are even on top and bottom. This step is easier to do with the help of an assistant. Mark where the hinges touch the window frame. Drill pilot holes into the window frame and attach the hinges with screws from their assembly kit.