Melbourne

Another suggestion that may help. Smear vaseline or similar all over the outside windowsill (if any). Anyone attempting to get in will not be able to get a grip on it to raise themselves up to that level. They'll have to bring a ladder or whatever which appears to be a level of forward planning that this nincompoop is not capable of. And bringing equipment makes noise. One very old trick is to attach a rattly thing or a small bell to the window at the top where it can't be seen from outside but will make noise if the window is opened unexpectedlike. Enough noise to alert you and get your phone up and recording if someone does break in. Like a shop bell - the old fashioned sort on a spring that tinkles when the door is opened.