Electricity meter application for house construction: What happens next?

The electrician does not have calibrated meters in stock. They always have to be ordered from the supplier specifically for the exact project.
With Westnetz, the electrician has the option to have the meter sent to them and can then install it themselves. That works quite quickly. Other suppliers send out their own meter installers. That usually takes a bit longer.
After installation, it’s best to record the meter reading so that there are no problems with the billing later. That happens with construction site meters more often than one might think.