Before shopping, determine if you need a full replacement or a simple repair. Check for: Drafts or air leaks. Condensation between glass panes (indicates seal failure). Difficulty opening or closing. Rotting or water damage on the frames. 2. Choose Your Window Style
Any you're leaning toward (modern, colonial, or farmhouse).
While DIY saves money, professional installation ensures the warranty remains valid. Get at least from local contractors.