Use of a wood buck inside of the concrete opening allows for easier installation of exterior and interior trim and also ensures a square opening for the window installation.
How to install a window in a concrete block wall.
In a concrete wall without wood framing install the window framework by fastening it into the concrete wall with self tapping concrete screws.
For a block wall installation fasten with rust resistant screws using a toe nail method through the jambs into the head and sill boards at each corner.
How to install a window in a concrete wall.
Score the outside surface of the cinder blocks with a circular saw fitted with a masonry blade then knock the cinder blocks out of the window opening with a small sledgehammer.
Cut a hole in the cinder block wall if you are enlarging an existing wall or putting in a new window.
Some preparations to the window opening can make the job much easier and leave the window prepared for interior and exterior finishing.