Yes. Somebody must let the installer in the house, since she/he will make connections in your home electrical center. It would also be good that the person present is the future main user of the system. This is because the professional not only installs the system, but also gives you instructions how to use it.
Unfortunately, we have to charge also the unnecessary travel if it would happen that we agree on the date and time, but cannot carry out installation. The amount is specified in our online shop product description for the fixed price installation.