EEA = European Economic Area, which is the previously 15, now 25 European Union countries plus a few other places which are not part of the EU, such as Norway.
In other words, you can follow BS7671/IEE Regs., or wire to French standards, German standards, or now even Latvian standards if you wish!
This is something which I queried a while back. If part P of the building regs. is going to be enforced by some local council inspector, is he really going to know 25+ sets of wiring rules, even though the national standards may have been moving closer together in recent years?
Besides, if the rules are going to allow standards as diverse as Greek and Estonian, then why not the American NEC, Australian, and a few others as well?
And I'm sorry to argue this point yet again, but as far as DIY work within an existing house is concerned, I don't think it will make a scrap of difference. Who really believes that any DIY homeowner who wants to add a light or a couple of sockets is going to notify their local council?