Please take care if following the initial reply as it contains numerous inaccuracies.
The current French regs are NFC 15-100 from 2002: do a search on this site and there was a link to a translation some years back.
If this is a re-wire and the property currently has a power-supply, you do not require any type of inspection nor carry out any notification: you can give your customer whatever you would in the UK. Strangely, for a country known for its bureaucracy, building and related trades are almost all self-certifying. There is nothing except self-preservation and action from the insurance company if it goes up in flames, that stops any person in France re-wiring their home.
The regs themself are comprehensive but not unreasonable: you could, if you wished, fit the house with British sockets as the regs do not specify that "French" sockets are used, only that sockets must incorporate an earth and a "shield" ( i.e. are child-safe ).
You can use T+E if you wish, but practice is single-core as T+E would fill the conduit used.
RJ45 needed in every "habitable" room i.e. not WC, laundry-room, although the kitchen is a "habitable" room.
I would be careful about taking anything from Promotelec at face-value as it is a marketing body set up by the electrical equipment producers and aims to increase the size of the installation " for your increased comfort ". For example, I remember one leaflet from them that recommended a maximum of 5 plugs per circuit whereas the legal maximum is 8 (with 2.5 mm2 ).
Good luck.