Efficient WC´s, taps and showers?
There exist many different tap models which have integrated water-saving functions. Hostel 7 Brasilia installed taps with a button function that only release a certain amount of water before you need to push it again. They also installed this system for their urinals. If you are not planning on renewing your taps it is also possible to install water filters on your current taps which will reduce the water pressure significantly.
The newest shower heads and systems on the market are more water and energy efficient than older models. It is possible to insert a water filter on some of the older models which will reduce water consumption by spreading it out better, not effecting the quality of the wash for the guest. If you have good shower heads with high water pressure, it is possible to reduce the water intake and also the electricity necessary to heat the water. This can be a significant saving on your energy and water bill.
Some water systems use a lot of time to heat up the water coming out of the shower heads. This can result in a lot of wasted water as guests wait to enter the shower until the water is warm enough. Look for possible solutions if this is the case for your property. These changes may seem expensive and time consuming right away, but in the long run everybody wins.
Different countries have different standards on the size of the WC´s water tank. But to implement a two-button system reduces the amount of water used per flush remarkably. A tip is also to put a filled plastic bottle inside the water tank as shown on the photo to the left. This will evidently reduce the size of the tank by restricting the amount of water being filled after each flush. Experiment how big a plastic bottle you need, just make sure it is sufficient water in the tank to flush what is necessary to flush;)