ᐅ Rainwater storage tank in the garage?

We are currently planning our house and garage.
The garage will be a prefabricated garage from Kemmler.
I came across Kemmler’s rainwater storage solution for the garage by chance on their website. Sounds good, but unfortunately too expensive (2,000).

I like the idea because an outdoor rain barrel is unattractive, not frost-resistant, and we don’t have a water connection in the garage.

I’m considering routing the garage’s rainwater downspout through the garage and installing a rainwater tank myself.

Does anyone have experience with this or any suggestions?

What exactly do you want to achieve? Is having water in the garage important? Refilling the windshield washer fluid? Why do you need water in freezing conditions? For the garden? Are you looking for a complete rainwater harvesting system? Or just to collect water for garden irrigation? And what exactly do you get from Kemmler for 2000 euros?

Water is intended to be used for garden irrigation, cleaning (bicycles, cars, motorcycle, garden tools, etc.), paddling pools, and similar purposes.
I want a simple solution mainly for garden irrigation with a connection option for a hose (not a complete rainwater system).
2000 EUR from kernm23 for an internal downpipe, a 500-liter (130-gallon) tank with water connection and hose connection, overflow into a drain pipe.

Addition: The garage section has a door at the back leading to the garden and is not used for cars but as a garden shed (garden furniture, toys, etc.).

According to your intended use, you don’t need water during freezing conditions (unless you like washing your vehicles when it’s cold). This means the storage tank can be placed outside, eliminating the need for water pipes running indoors (which I suspect is a major cost factor). I would want those pipe entries to be installed professionally. If they are done poorly and end up leaking, repairs could easily cost around 2,000 euros.

Check hardware store catalogs to see how much 500-liter (130-gallon) tanks cost. Only you can decide how and if you want to make it look “nice” outside. Depending on your garden, 500 liters (130 gallons) might be insufficient; it might be better to invest in a larger capacity, which could also simplify the technical setup (for example, placing it outside the garage).

Why not simply drill a well? No water shortage in summer and manageable costs. It could also be done right in the garage.