Using rainwater for the house?!

Hello, from an ecological point of view, there is actually nothing against such a system. But if you want to save money with it, in the end not much comes out of it. First, you have to calculate the costs for the whole system. If you build without a basement, the cistern has to be buried outside. That also means that everything must be frost-proof or only used during the frost-free period. Then there is the fee for the second water meter. You have to have it because the wastewater charges are calculated based on it. Besides, there are also electricity costs for the pump. Then you certainly also have to consider how many people live in the house and how long they are present during the day.
Regards, Thommi

I guess that someone planning something like this cares less about the costs and more about the environmental benefits.
Hellboy

when I think of our many summers in which there is more rain than sun, then I can easily imagine that it will eventually pay off financially.

I think it's great when someone puts that much thought into something. I am sure that there are more such good technologies that are unfortunately far too little known.

Best regards Pudel

In a country where it rains so often, it is actually strange that people did not come up with such technology much earlier.
I would like to have that too.
Best regards, Bauzaun

Hello friend of the rainy wet,

Using rainwater is a fine thing that, in my opinion, has more advantages, even if financially it is not really worthwhile.

You only save the amount for the portion of drinking water consumption that is replaced by rainwater. The wastewater fees remain the same except for the portion used and infiltrated in the garden.
On the other hand, there are a number of additional costs, starting with the purchase, additional costs for piping with absolute separation from drinking water including refill device, additional electricity costs (although minor), additional water meters (purchase costs for 2 pieces), etc.

However, many municipalities offer financial subsidies for the installation and use of such a rainwater utilization system. But certain conditions must be met, so inquire beforehand at the building authority of the municipality/city. The amount of these subsidies varies regionally.

We ourselves use such a system for toilet flushing, the washing machine, of course for garden irrigation, and to fill our small swimming pool (10,000 l capacity).
Naturally, rainwater is not as pure as drinking water and occasionally the filters must be cleaned. The cistern should also be cleaned every few years, preferably at the end of a longer dry period.
Sometimes slight grayish marks can be seen in the toilet, which disappear by themselves and do not bother me at all. But here you do not waste any precious drinking water.
Since rainwater practically contains no lime, less detergent is needed, no fabric softener, and the machine cannot calcify.

However, the cistern should be large enough. The required size depends on the number of residents and the garden size to be irrigated, whereby the plants and especially the lawn can also be pampered (too little root formation with too much watering).
Ours has a capacity of just under 13,000 l, but our garden is also almost 3,000 m² in size. Even after 8 weeks of drought there was still a residue of about 2,000 l left. This was the right time for cleaning.
For a normal single-family house (4 people) and a common property size, a cistern with about 6,000 to 8,000 l should be completely sufficient.
Cisterns made of precast concrete parts, which look like a huge bucket with a lid and an entrance on top, are probably the most inexpensive solution.

Overall, I am very glad to have made the decision for rainwater utilization at that time.

Best regards
Danton

Engineering and Planning Office
Dipl.-Ing. Thomas Brandenburg
Consulting Engineer and Building Expert
Insurance Specialist (Construction Contract)

How much does a rainwater system cost?