Another pint about the "gas jubilee clips" they are for LOW PRSSURE hose. If you have an auto changeover system it is normally high pressure hoses, that are normally bought ready made. This is something like what I will use, regulator, automatic changeover, over prerssure shut off, emergency isolator, pressure test point and ready made hoses all in onne complete kit. https://www.bes.co.uk/700h-two-pack-automatic-changeover-kit-with-opso-en-13786 What could be simpler, screw it to the wall and connect the gas pipe to it.
Our water, electricity and telephone all had to come from the other side of the road. As luck would have it, Scottish water gave the cheapest price to make the road crossing, and I was only having (and paying for) the road up once.
Now that was handy, because water goes deepest, 900mm down up here. So when the sub sub contractors (SW contracted it out and they subcontracted it to someone else) had the trench open for the water, while they were connecting it, I back filled the trench partially and laid in ducts for the telephone and mains cables. In fact I had the phone cable so I pulled that one through the duct and just left a draw string in place for the electricity supply later.
The vertical separation from the water to the electricity was enough, and by putting telephone one side of the trench and mains supply the other, achieved enough separation between those.
All done in a couple of hours, trench closed and everyone happy.
I won't tell you how all 3 in my present house came to be in one 65mm duct under the road!!!
Ducting is your friend assuming you've got the usual electric, water and 'phone going in...
From the previous discussions, dig it 750mm deep x 300mm wide and lob the water duct in. Back fill to 450mm and chuck power on the left and telco on the right and back fill the trench.
Job done, and Robert's your granddads son...