Window Frame Types

What is a Nail-On Frame Window?
Nail-On frame windows are used when building a brand new home or room addition where the window will be installed prior to the completion of the exterior wall surface (Usually stucco or masonry).
What is a flush fin frame window?
Flush fin (also known as Z-Bar) frames are designed to replace aluminum frame windows while preventing damage to stucco and interior dry wall. It consists of a vinyl fin that surrounds the perimeter of the window frame and is flush with the exterior frame of the existing window. This is the most commonly used replacement window type.

Before and after using flush fin replacement vinyl windows

Before and after using block frame replacement windows
What is a Block Frame window?
It is a non-finned frame that can be used as new or retrofit installation in a block (concrete) wall application or as an existing wood window replacement frame.