How to Replace French Doors With Windows

Remodeling an exterior wall to replace an outdated or seldom-used pair of French doors with new window units can improve the visual appeal of a room, as well as adding some usable wall space. The method used for 6-inch exterior wall framing can be adapted to any wall thickness by substituting the framing materials.

Things You'll Need

• Hammer
• Pry bar
• Nail set
• Reciprocating saw with metal cutting blade
• Hacksaw
• Screwdriver
• Stud finder (optional)
• Tape measure
• Hand square
• Circular saw
• 3½-by-5½-inch framing lumber
• Casement or double-hung window unit
• Wood shims
• Utility knife
• Handsaw
• 16d sinker or box nails
• 8d finish nails

Instructions

Removing The French Doors

1. Remove both doors by removing the hinge pins. The hinge pins can be loosened with a nail set or awl and hammer to tap upward on the bottom of the pin to raise it for removal.

2. Remove the interior door casing from the perimeter of the jamb. Remove any exterior door trim from the jamb.

3. Detach the door jamb frame by cutting through the shims and nails located between the jamb and adjacent framing around the perimeter of the door frame. Use a hacksaw or reciprocating saw with a metal cutting blade. Remove any screws or finish nails securing the door's sill.

4. Remove the door frame assembly from the opening by tilting the frame outward from the top.

Wall Framing For The New Windows

1. Cut one 3½-by-5½-inch board to the full-width dimension of the wall opening. Place on the floor of opening and flush with existing framing on each side. This will be the bottom plate of the fill-in framing and should fit snug at both sides.

2. Locate the nearest wall stud to the door opening that is not part of the opening’s framing and mark that stud's center at the base of wall. Continue the existing stud layout onto the bottom plate cut and placed in the opening in Step 1. This will keep the new wall studs in the opening on a layout consistent with the existing wall framing.

3. Mark the location and rough opening width of the new window unit on the bottom plate. Verify that the existing header height is consistent with existing windows in the house, as well as the window manufacturer’s specifications.

4. Cut a 3½-by-5½-inch board to the dimension from the new window’s right-hand rough opening mark to the right side of the wall opening. Place this piece on top of the bottom plate and flush with the right end. This will be the right side top plate of the fill-in wall framing. Repeat for the wall space to the left side of the new window's rough opening.

5. Transfer the wall stud layout lines onto the top plates cut previously, using a hand square.

6. Measure the distance between the bottom of the existing header and the top of the bottom plate minus 1½ inches. This will be the length of the fill-in wall studs. Cut 3½-by-5½-inch wall studs to this measurement. Cut one stud for each layout line, omitting those within the new window’s rough opening. Full-length studs are only used to the sides of the window location.

7. Lay the bottom plate and two top plate pieces on end and parallel, spaced sufficiently apart to install the wall studs cut previously between them. Install one wall stud at each layout line marked previously. Secure with two 16d nails through the plate into the end of each stud. Install each stud to the same side of the layout lines to ensure consistent spacing.

8. Measure the dimension of the new window’s rough opening height plus 1½ inches down from the top of the top plate and mark the wall studs on both sides of the window opening. Square this line across the edge and inside face of the studs. Verify that this mark is also the same distance from the bottom plate on both sides.

9. Cut two 3½-by-5½-inch boards to the width of the window’s rough opening. These are the new window’s sill plates. Install one sill plate below the mark determined previously. Secure with two 16d nails through the wall studs and into the end of the sill plate on both sides.

10. Measure the dimension between the top of the bottom plate and the bottom of the sill plate installed previously. Cut one 3½-by-5½-inch board to this dimension for each wall stud layout line within the window’s rough opening. These are called “cripple” studs.

11. Install the cripple studs cut previously and install one on each wall stud layout line below the window sill plate. Match the layout across the sill plate and secure the cripple studs at both ends with two 16d nails through the plate into the end of the cripple studs. With all the cripple studs nailed in place, install the second sill plate on top of the first sill plate and secure with 16d nails spaced 8 to 10 inches apart.

12. Stand the wall assembly upright and insert in wall opening. Align the top of the wall with the existing header and the bottom with the existing wall framing on both sides. Secure with 16d nails into the floor, header and sides as needed.

13. Complete installation of the new window unit according to the manufacturer's specifications and required flashing before proceeding.

14. Install wall insulation, interior and exterior wall finishes to match existing finishes.

References

• American Wood Council: Details of Wood Construction, See Pg. 8-9, Fig. 43