In my house I have a significant distance between my bathroom and water heater. Every time I'm taking a shower or need hot water, I have to keep the water running for quite some time before it gets hot.
So, I guess the most common approach would be to shorten the time until the water gets hot by installing circulation, smaller pipes etc.
But, I'm looking for advise on a different approach - how the cold hot-water can be saved in a smart way, instead of just flushing it down the drain. Maybe using some valves, temp sensors etc. The water can then be used for flushing the toilet, watering my garden or something.
I'm thinking both high-end and simple solutions are of interest. Anyone who has done anything like this and can share some ideas/experiences?