There it is, right in front of you – how much of your one-liter water allocation is left can be clearly seen in the tube above the tap. Want to use more? Sorry, but you will have to watch it refill and start over again if you go over your rations.

Somewhere between a point-making conceptual design and real-life proposal, the 1LL by Yonggu Do, Dohyung Kim & Sewon Oh stores up a precise amount of water between uses, then pours it out on demand – a little like the self-stopping hand-drying blowers or click-and-stop sheets of paper towels found in public restrooms.

Most faucets can waste up to six liters of water in half of a minute if left unchecked – and we don’t notice how quickly it all drops through the sink and down the drain. From a functional perspective, though, this idea poses a number of practical problems. How does one keep the inside of the tank clean and clear without tricky washing techniques? And what about warm-versus-cold options? Perhaps room temperature is all that one needs in a commercial, civic or public situation, but that limits the potential applications if so.