What methods can be used to make a dark colored window become opaque?

Question

Currently, I have some problem regarding some windows, which are dark-colored. During the day time, people outside the windows cannot see people inside the windows. However, during the night time, people outside the windows can see people inside the windows.

Some more, I cannot place bindings such as curtains as the owner of the house prohibit me from doing it. What methods I can use to prevent people outside the windows to view me?

Note: The room have these dark-colored windows and the room is at the first floor. The room is directly opposite of a 4 lane road and the room is rented.

Do let me know if further information are required.

Extra information: I search but can only manage to find the following picture that have similar characteristics as the windows that I am referring to:

Answer 1

You're not allowed to install blinds or curtains, are you allowed to apply anything to the glass?

In order of most realistic to least I would suggest

• Applying a reflective coating / thin film to the windows, such as is used in one way glass, I believe a consumer grade version of this can be purchased on a roll and may be made of mylar or some similar non-reactive plastic
• Place a decorative room divider such as these between the window and the line of sight you wish to block. You'll still get good light transfer during the day time but more privacy at night.
• Using masking tape, painter's tape or some other easily removed solution, tape either a lightweight fabric or decorative paper over the windows. It ruins your enjoyment of the window, but gives you the privacy you want

Barring any of these solutions ask the land lord for ideas, since they've likely dealt with it at this location before.

Answer 2

During the daytime, the daylight outside reflects in the window and drowns out the light that comes from inside. The darkening of the glass only reduces the light that comes out the window, and at night there is no reflection to drown out the light, so the light from the inside can still be seen although it's reduced.

At night you have lights on inside, which of course increases the light that comes out. Dimming the lights will reduce the amount of light that gets out.

So, there isn't much you can do, unless you install massive floodlights to light up the surroundings at night, to get the same effect as you have at daytime.

Answer 3

Perhaps the simplest method is to not mess with the windows at all.

Japanese Shoji Privacy Screen

If you set these up a foot or so inside the windows, they will still let light in during the day, but provide privacy at night. They could even be completely set aside diring the day if desired.

Answer 4

You can go for the following options:

1. reflective coating
2. masking tape
3. simply use curtains on a glassed window