The person carrying out the installation should be well qualified to do so. Persons who are not competent should not be allowed to carry out any electrical work.
This qualification should be documented and the installer should have a proven experience in the work of carrying out electrical installations and a proven knowledge of the rules and regulations of the applicable standard.
Follow-up trainings should be provided to make sure that the installer maintains his skills.
If a homeowner is allowed to undertake the wiring of the electrical installation of his own home, a third party like the Authorities or the Network Distributor, should test to see if he has sufficient knowledge to do so.