Full-Frame vs. Insert (Pocket) Window Replacement
What's the difference?
Insert (pocket) replacement keeps your existing frame and slides a new window into it. Full-frame replacement removes the window down to the rough opening, including the frame and sill.
Cost and when to use each
Inserts are faster and cheaper because less is removed and rebuilt. Full-frame costs more but is the right call when frames are rotted, when you're changing window size or style, or when you want to inspect and re-flash the opening.
Ask your installer
A good installer will inspect for water damage and tell you honestly whether your existing frames can support an insert. Improper installation can void the manufacturer warranty.