Alternative ways to secure corridor window without installing grilles?

[MikeyBoy 0]

Hey guys, I stay in one of those flats facing the corridor. Unfortunately my family has voted against installing window grilles along the windows facing the corridor. Personally I feel like it is a necessary security measure but I am outnumbered on this matter.

Just wondering any ideas of how to secure sliding windows facing the corridor if installing grilles is not an option?

Thanks for your input!

Edited November 26, 2017 by MikeyBoy

[esc 0]

simple thing i did was i bought a couple of wood dowel (wooden rod) from ArtFriend.

Cut them to size. With the windows closed, leave it in the sliding window "groove", if i am away for a few days.

This will prevent anyone from sliding the window open because the rod will block any sliding movement.