I want to install an outdoor double socket for occasional use with the mower, power tools, patio heater, etc. rather than having the extension cord trailing out of the window. My intention was to have an RCD plug into an existing internal switched socket & from that run 2.5mm Arctic cable in a conduit through the external wall. The cable will exit high (2.3m) in the wall and run approx. 3 or 4m along an external block built wall before terminating at an IP66 rated 13A 2-Gang weatherproof outdoor switched socket. The cable run and socket are under the cover of a polycarbonate roof, so 'external' but not fully exposed to the elements. I plan to run the external portion of the cable through IP66 rated flexi conduit fixed near the top of the external block wall to further protect from UV & water.
The cable will be unplugged from the internal socket via the RCD plug when not in use, so what I'm looking for is essentially a 'fixed' extension cable for occasional use. Is there a requirement for an REC to carry out or to sign off on this kind of work? Any thoughts or comments?