Thanks for the kind comments people much appreciated. I've loads of pics of the build if that's of interest to people and I'm happy to share.
When I started I didnt really have any building skills of note but I've mates who I called upon who have and I worked with them on it and just learned as I went along. Was really enjoyable and probably took approx 12 months or so from start to finish.
All cables (water, electric, internet) come from the house and I dug a trench approx 1 foot deep (meant to be 2 foot + deep but I hit rocks and had a stinking hangover when I started that day so I thought fuck it
) and put lagging around it and put it all inside drain pipe then buried it again. Had no issues with it all.
With the toilet I knew next door had a waste pipe that ran behind the room I built so I offered to replace 6 fence panels on our shared boundary to tap into their waste pipe from my new toilet. Dug down and found it and although a messy job it was a lot easy that digging a waste pipe trench from the top of my garden to the drain at the other end.
YouTube is your help when it comes to stuff and just give it a go. Honestly if I can then anyone can!!!