I have aluminium windows that were installed in the 1990s. They have 9mm cockspur handles. The windows are still in good condition so I don't want to change them but I'd like to replace the handles and add a night vent keep.
The handles are easily replaced with the Securistyle W10 Virage which is a straight swap and I can use the existing screw holes: https://www.handlestore.com/w10-cockspur-window-locks#block-related
The night keep that goes with these handles is actually designed to be screwed into into upvc windows but it will fit my aluminium windows. It's installed as shown on this page: https://www.handlestore.com/night-vent-keep (see all 3 pictures)
The problem is that there aren't any pre-drilled screw holes for the night vent keep so I will need to drill new holes into the window frame for this and I'm worried that I may accidentally break the glazing. How far in can I drill?
Photos attached showing window from outside and inside with measurement.
The handles are easily replaced with the Securistyle W10 Virage which is a straight swap and I can use the existing screw holes: https://www.handlestore.com/w10-cockspur-window-locks#block-related
The night keep that goes with these handles is actually designed to be screwed into into upvc windows but it will fit my aluminium windows. It's installed as shown on this page: https://www.handlestore.com/night-vent-keep (see all 3 pictures)
The problem is that there aren't any pre-drilled screw holes for the night vent keep so I will need to drill new holes into the window frame for this and I'm worried that I may accidentally break the glazing. How far in can I drill?
Photos attached showing window from outside and inside with measurement.