Every Spanish cave house that undergoes renovation needs complete rewiring and an upgraded power supply. Many old Spanish cave houses have nothing more than a 125 volt supply and a few light sockets, with not one power point in sight. Even more modern cave houses have a pretty feeble 240 volt supply with a 16 amp breaker protecting the circuits. Totally inadequate for modern lifestyles.
New electrical regulations introduced at the beginning of 2004 have brought Spain into line with the rest of Europe. The regulations call for improved earthing and insulation plus earth leakage and thermal overload protection to protect circuits and users alike.
Unless you are fully familiar with low voltage circuitry it would be prudent to employ a qualified electrician to design and install the circuitry. If you want to save on this you could do the work associated with channeling the electrical conduit and placing sockets and junction boxes and leave the electrician to do the wiring connection and testing.