One of the powerline adapters would go in a power plug near your main router, and be connected to the router via ethernet.

So would i be right, that i would need to still need add a wireless router to the powerline adaptor so i can get wifi outside the house? I had a quick look and noticed the wireless extenders? Are they not the same? runs over powerline but instead of ethernet out, it has wireless out? or are they not recommended If they don't work you always have the option of taking an actual ethernet cable between the two buildings (I'm assuming this could be buried, but would it need trunking?). Will powerline adapters usually work between a main building and an external dwelling? I'm assuming it'll depend on how the wiring to the external dwelling is done (eg, I'm assuming it won't work if the second dwelling has a a separate board with its own meters?). Just be mindful powerline adapters come with different capabilities regarding maximum speed, with the cheapest typically relatively slow. or alternatively just buy a pair of powerline adapters s/h off TM if they work, you've saved money over buying new, but if they don't work for you you'll not lose much at all selling them on.

There are plenty of threads about powerline that can recommend brands. It doesn't work well in all houses so buy from somewhere with a good return policy. For the sleepout you should consider powerline networking and a cheap access point.

Goodsync 9.9.15