With a stem-wall height of approximately 3-feet, the rough frames for the south facing windows are essentially just above the wall height. See photo to left (before shot).
Anchor bolts were cemented into the top of the stone wall to secure the rough window frames to the wall. I decided that instead of simply cobbing under the windows and plastering (a potential future maintenance hassle), that I would just continue the stone masonry up to the bottom of the window frame, creating a attractive and maintenance-free surface.
I use old bicycle tire tubes stapled to the bottom of the window frames (not shown) to create a 'seal' between the stone and the frame. This keeps water from leaking in from the sill.
The photo above shows completion of the first sill (inside looking out). The sill on the outside will slope slightly down in order to keep rain from pooling and working its way under the sill.
Smaller flat rocks were collected for this phase of the building project. I initially thought this part of the stone work would be a real pain; but seeing how the sills add a finished look to the stonework and the creative aspects of fitting stone, is making this task quite rewarding.
(Note: Click on any photo in this blog to enlarge)