Friend services not allowed
If the electrical system fails, it can be tempting to ask an electrician for a friend's favor to save a few bucks. However, this is not a good idea. In order for work for others to be legal, the work must be done and documented by a registered electrical company. The electrician you know may be employed there, but it is the company itself that must take on the job.
Request Declaration of Conformity
As the owner and user of a home or holiday home, you must therefore use a registered electrical company for all changes and updates to the electrical system. This is to ensure you as a consumer, both in relation to electrical and fire safety - and legally, should damage and problems arise afterwards. All work on the electrical installation must be documented with a declaration of conformity, and this can only be issued by a registered electrical company.
Electrician in your own home
If you are a trained electrician and have three years of relevant experience from the construction and maintenance of low-voltage electrical systems in buildings (after passing the trade test), you can do work on the electrical system yourself in your own home and in your own cabin. "Own home" means where you live permanently/are registered in the National Population Register.
Important documentation
The work must be documented in accordance with the requirements of the relevant regulations, in the same way as a registered electrical company is required. Sign the documentation with your own name. This documentation must accompany the electrical system. If you are going to sell the house, it is a good idea to attach a copy of your trade certificate and documentation of relevant practice. Thus, the new owner receives documentation that you met the requirement to be able to have the professional responsibility for the job you did.