Rainwater from the cistern also for laundry and toilet flushing?

In the future in Germany, you will need the 15k cistern for your garden to keep plants and lawn alive

But only in summer. During the time when it rains a lot and the cistern is full, you don't need it for the garden.

It is true that the water might not always be sufficient in summer. However, modern domestic waterworks are equipped with a potable water replenishment system with separation RW / TW. This way, you can still flush your toilet even during drought periods.

I find WC use sensible alongside garden irrigation. If there is no very hard water prevailing in the region, I personally prefer TW for laundry. But I can only justify this emotionally.

Toilet deposits can form, but this depends strongly on the filters, the intake device (floating extraction), and the overflow siphon, as well as the quality of the discharged water. Impermeable surfaces and green roofs (high humin content) definitely should not be discharged.

Although we have the insulated Silentio domestic waterwork, ultimately it is still a pump that you can hear. Since the technical room is in the basement, it doesn’t bother us. But in the ground floor with adjacent living rooms, you should also consider the additional noise and vibrations beforehand.

Under no circumstances do it. You will only get problems with dirty filters and dirty toilets. I hardly know anyone who would do it again or is satisfied.

That is also the reason why we didn’t do it.

There is no reason to do it. It is neither ecological nor economical. It is the easiest decision in house construction. One should rather invest their energy in ventilation, heating, windows, lights, laundry chute and so on....

Usually, the cistern is not even enough for garden irrigation if it doesn't rain for two weeks... Because of the deposits, the double pipes, etc., it doesn't make sense. See

So we did it without a washing machine. And we would do it again anytime, and it works great if you consider a few small things. For us, the water does not smell, there are no deposits (I don't know what it looks like in the toilet or the cistern). And you can actually bridge a small period of time. I can see how little fresh water we use by looking at our water softener compared to my brother's, how rarely we have to refill salt. Conclusion. Financially, it never pays off for us. We also put in an extremely large amount of technology. But it works great because of that.