In many cases a geyser is installed in each office toilet that only supplies hot water to the hand basins and no-where else. In those cases, you should consider switching that gesyer off permanently. The reason for this is that when washing their hands after going to the toilet, most people will not wait long enough for the hot water from the geyser to reach the taps, so hot water flows out of the geyser and along the pipes, but very little, if any, actually gets to the user. But at the same time, quite a large amount of cold water flows into the geyser and cools down the water inside which eventually results in the electric element switching on. This is a large waste of energy for very little benefit because it takes quite a lot of energy to heat water.
Most people will not be overly concerned if hot water is not available in the rest rooms, but if it is available many will use it as described above.
In addition, very little hot water is withdrawn from these geysers during any particular day which results in heat loss through the geyser walls being the primary consumption of energy in each geyser. So energy is steadily being consumed again for very little benefit.
Switching off the geyser is a simple action that costs nothing but will contribute to your energy efficiency drive.
One should also ensure that flow restrictors are screwed into all taps in the rest room. These are standard fittings available for most taps which slow down the flow out of the tap while adding air bubbles. This makes the water flow feel very pleasant for users. But more importantly, significant amounts of water are saved because people tend to wash their hands for a specific amount of time regardless of the water flow rate.