How to Replace Odd-Shaped Windows

When you want to replace custom or uniquely shaped windows, you have two practical options: Order custom replacement windows with modern efficiency features and operation, or re-frame the rough window opening to accommodate standard-sized and -shaped windows. Ordering custom windows may add to the cost, but the construction of a new frame coupled with the cost of the required interior and exterior patchwork re-framing requires may be just as costly. If you appreciate the uniquely shaped windows and they are a visible design statement in keeping with the exterior character of your home, they may be worth replicating.

Things You'll Need

• Tape measure
• Level
• Small crowbar
• Replacement window
• Treated timber for framing
• Wood shims
• Silicone caulk
• Expanding spray foam insulation & fiberglass insulation
• Saw
• Nails
• Hammer or nail gun

Instructions

Measure Your Windows

1. Take the measurements of the windows you wish to replace. Measure at the top, bottom and middle of the window for the both the width and the height. Note as well the depth of the frame and whether the frame is made of wood, vinyl or aluminum. Research replacement designs and size options, get quotes and order the replacement window. After it arrives, remove the old window and discard or recycle.

2. Saw into the old rough wood framing, lift with a crowbar and remove from the opening. Cut new lumber to build a rough frame to the specifications of the new size replacement window. Nail the rough frame together, place it in the opening and nail to the surrounding structure.

3. Run a bead of silicone caulk along the clean sill unless the manufacturer's specifications say otherwise. Set the new window into the rough frame, check for level and plumb, and add wood shims as necessary. Nail the mounting flange to the rough frame to secure the window. Again check for level and plumb.

4. Spray expanding foam insulation in any crevices between the wall structure and the rough frame and between the rough frame and the new window. For larger gaps, insert pieces of fiberglass insulation.

5. Patch any interior or exterior building finishes and install wood or vinyl window trim pieces to finish the installation.

References

• Custom vinyl windows in complex shapes
• Pella's signature and custom shaped windows.

Resources

• Purveyor of replacement windows several materials and shapes.