I had the pleasure of staying in the UFO at the Thee Hotel over midsummer. Since the room is suspended between three pines there is no running water. Instead, there are shared showers in a separate building and an incineration toilet in the UFO.
The toilet faucet is quite a feat of ingenuity. It basically consist of a transparent plastic bottle without a bottom. It is mounted upside down and a simple lid is placed on top. The part facing downward is cone shaped and in the very bottom a loose smaller black cone rests. The small black cone stops the water from pouring out from the container. However, when I push the black cone upwards, water pours out around the black cone and onto my hands.
There is no sewer drain from the room so instead any water used for washing ones hands and brushing teeth is simply collected in a bucket under the basin. The water has to be carried, before and after use, up and down the small ladder … oups, I mean up and down the landing gear of the UFO :)
By making the container clear and the function so “primitive” the designer made me and my partner very aware of the amount of water we had at our disposal. This caused us to adjust our behaviour, which is a sign of very good interaction design!