Comment by niobe

Agreed, if anything an electrician was needed, not a professional PC builder.

The picture shows two power supplies. Powering what is effectively one appliance from different circuits is a definite no-no, and I can't think of any circumstance where it wouldn't be in a home.

If his mains supply was sufficient to run the server and the house in the first place then the simplest solution would be to simply upgrade one of the MCBs/RCBOs on one of the circuits to the required capacity. I am not sure a landlord would even notice something like that, and if the house is wired correctly in the first place, it's unlikely to be dangerous. So going from say, 6A to 12A, on a 20A mains supply is generally fine if the gauge of wiring is correct.