Water counting for outdoor area (deduction meter)

hello

we have the following in our bylaws:

The deduction meter must be permanently installed in the water line or pipe to the external water tap.

if you now look at the DIN/VDI regulations regarding branch lines, the water tap must be located directly on a ring main (otherwise there is a risk of contamination). Consequently, theoretically a water meter cannot be installed in this line as they envision.

now my idea: I attach the water meter (frost-proof version) to the frost-proof pipe section from the wall (it is actually the external water tap) and screw another water tap behind the meter and declare this as the external water tap. furthermore, the whole thing is enclosed in a large wooden box.

do you think this could work? according to the authorities, nobody wants to check anyway, I just have to report the meter reading every year. the water association, which reads the normal meter, has nothing to do with the authorities.

The ring main will presumably lie within the building envelope under the screed, the external water meter on the outer wall, conveniently between knee and hip height.

So enough space to install an internal water meter before it goes outside.

The ring main goes up directly to the water tap, which goes completely through the wall. Everything else is theoretically not allowed either, as it is a branch line without long-term consumption. Furthermore, the line is in the living room and would probably look really great if a meter were sticking out next to the cabinet. I have now attached the meter outside and am registering it as such. The meter is frost-proof and therefore tamper-proof. Of course, anyone can steal it. According to the authorities, no one comes to inspect; in the end, it is allowed in many other districts as well (because theoretically it would not be allowed according to VDI/DIN/guideline - branch line...).

Why actually not allowed? My plumber installed a second outdoor water tap on the south terrace and connected it with a branch line from the sink. Only cold water. Where is the problem? Karsten

I am aware of two possibilities. The better one is to include the outdoor faucet in the ring/main line. The connection is made via a T-piece to the ring, followed by a meter, then the faucet. However, this should have been planned, which was probably neglected in this case. A branch is possible afaik, but then no longer as a drinking water extraction point. Those who are strict then hang a sign on the faucet outside. And keep the line as short as possible.

Then just let the first ten liters run off, after that you can drink it too. In the Congo, they drink something completely different.