It can be done, and it is the best way for certain situations to my mind:
1. Use one way glass film to prevent people seeing it.
2. People can still see it at night if a light is on inside the house, so use a black box sealed to the window to prevent this and to allow continuous vision to outside ( one way film would work in reverse at night). Anything truly opaque will work, even a plastic bag if it's thick enough. Irregular shapes are preferred in some respects.
3. Use a camera that meters through the lens, not through a hole in the body.
4. Infrared will not work if it is mounted on the camera as this will reflect as stated previously.
5. Black tape over a separately located IR light will disguise the lights but still allow light out. This will go through the glass to outside, but I'm not sure how much filters out if behind one way glass.
Good luck.
