Drilling into uPVC window frames?

veritree

Hey there, I am building an enclosed catio for my cats and I want to know if it is safe (and sturdy!) for me to drill and fix a wooden frame of the catio to my uPVC conservatory? I want to make sure that the structure is sturdy and escape proof- 2 of the 3 corners (it's triangular in shape) will be fixed to the masonry. 
Thanks in advance!

grumbler

I don't see how this can be unsafe.

How sturdy it is, depends on your skills. Generally, pretty thin plastic doesn't hold screws very well, but my old windows have locking handles fixed with screws. Many manufacturers used 'blind'/'pop' rivets instead.