Hello from the States!
I am responding to the issue of drilling holes in rental property.
Solution:
1. Raise a window.
2. cut a 2x4 to the width of the window.
3. Drill how ever many holes you need to run your wires (and terminals/connectors)
4. Be sure to get two sizes of weather-proofing foam strip like for a door or a window or a window air conditioning unit. Get a real size and a small size. Weather strip the 2x4. DO NOT go cheap and avoid this step!!
5. regular caulk for the space around the wires in the 2x4.
It ain't gonna be pretty, but you are guaranteed not to have landlord issues when you move out.