Disclaimer – all these stats and the relevant goals set in the app are approximations, and proper research and statistics would need to be gathered by Crowne Plaza in order to determine what a saving limit would be. For design purposes, I’ve placed a numbered goal on these rough calculations.
The UN say that a human being needs 50 litres of water per day in order to prepare meals and to have enough for personal hygiene. 50 litres of water per day are necessary in order to avoid diseases and to retain efficiency.
In Germany, the water consumption per person amounts to 121 litres water per day. About 1/3 is for toilet-flushing, 1/3 for body hygiene and another third for laundering, washing the dishes, cooking and drinking. For cooking and drinking, we need about 5 litres per day.
Therefore – considering guests will not need to cook / do laundry / wash dishes, and will only be using water in the bathroom, a maximum of 80 litres per person per day is needed.
The average household uses roughly 20 kw per day, which is the maximum I’ve set per day.