install movable insulation

6 shutterstock_65418634

initial requirements:

  • Windows already are well sealed and homeowner is willing to operate shutters

materials needed:

  • 1 1/2-inch rigid extruded polystyrene insulation (you can use three 1/2-inch pieces)
  • 2” x 2” fir lumber
  • Masonite
  • Construction adhesive
  • Corrugated fasteners
  • Weatherstripping
  • Handles
  • 3/4-inch drywall screws
  • Latches and hinges (for hinged shutter)
  • Exterior white paint
  • Paint thinner for clean-up

tools needed:

  • Utility knife
  • Cloth shears
  • Carpenter’s square
  • Paint brush
  • Electric drill
  • Carpenter’s tool belt


  • Mitre saw or circular saw

required skills:

  • Basic carpentry for pop-in shutters
  • Skilled carpentry for hinged shutters

annual energy savings: $.19 to $.32/sq ft of window

average time required: 1 to 5 hours/window

project steps:


  1. Measure the height and the width of the interior window frame.
  2. Cut 2” x 2” lumber for the frame as shown.
  3. Assemble the frame, keeping all corners at right angles and using corrugated fasteners.
  4. Cut the masonite to fit over the top and the bottom of the frame.
  5. Cut the insulation to fit inside the frame.
  6. Apply glue to the bottom side of the frame and nail one piece of masonite in place.
  7. Set insulation in the frame and attach the top piece of masonite.
  8. If you wish, apply the decorative fabric or adhesive paper to the interior surface of the shutter.
  9. Paint the outside of the shutter white.
  10. Install handles for easy removal.
  11. Install weatherstripping all around the shutter so that it fits tightly in the window.


  1. Measure the dimensions of the window frame and cut 2” x 2” lumber for the frame.
  2. Follow steps 3 through 9 for pop-in shutters to assemble the shutter.
  3. Attach hinges and a latch to the shutter and the window.
  4. Install weatherstripping all around so no air can leak around the shutter when latched.