Choose the guide that matches your installation: pocket or retrofit, full-frame brickmould, block frame, or jamb depth. Each guide explains where to place the tape, how to check the opening, and what dimensions to record before ordering.
A pocket — or retrofit — replacement fits your new window inside the existing frame. Your interior trim, exterior finish, and siding stay untouched, so it's the fastest, least invasive way to replace a window that still has a solid, square frame.
A brickmould replacement removes the old window right back to the brick, and the new unit arrives with brickmould already attached — it fills the masonry opening in one piece. It's the standard full-frame replacement for brick and stone homes.
A block frame window has no nailing fin and no attached brickmould — a clean square frame that slides straight through the opening. It's the full tear-out option: everything comes out back to the rough or masonry opening, and trim is finished after the install.
Jamb depth is the front-to-back thickness of your wall where the window or door sits — from the interior finished surface to the exterior face. It decides the frame depth you order and whether extension jambs are needed to meet your drywall cleanly. It takes one minute and it's the most-forgotten number in window ordering.