For me its a no brainer - dig a trench, put in the electric cable on one side of the trench and the water pipe on the other. If there is main gas to the property then I would consider putting in a gas pipe as well, capped off at both ends as a bit of (cheap) future proofing. If the ground has stones then put the pipe in land drain plastic pipe or similar (and if SWA cable is not used then put that in as well)

Boss needs to work out likely loading before doing anything! Theres no point in running a 2.5 SWA for some LED lighting and then decide he wants to use a welder in the barn. Alternatively lay a duct with a draw wire in it and he can pull in whatever cable he wants when the time comes. If its running across a field make sure its laid deep enough toclear any future ploughing/groundwork

No need to go lower than 750mm at all. Need to get a grip on potential electrical loading and what is possible from the house supply. Realistically if youbare going to want to do anything sensible you will be looking at 6mm minimum.

In the UK, water needs to be 750 mm. There needs to be 375 mm cover over everything.

Work out what the power loads might be (especially kettles and heaters etc) then ask the electrician who will connect, test and certify it what size cable is needed and what earthing is required.

EASYGRID-10000- Offgrid system in powder coated steel enclosure (1513 x 824 x 1051 mm WxDxH) - includes 41 kWh of 14,517.37 1.00 14,517.37 LA-41KWH gel 2 volt batteries (48V), 10000VA inverter/charger, control panel with remote data logging, 6.8kW solar
charge controller and genset auto start connection.

002 EASYGRID-SOLAR- 5 string solar array kit - Comprises of 25 x 275W Canadian Solar Polycrystalline panels - each panel 3,695.80 1.00 3,695.80 250V-6.8KW dim 1650x992mmx40mm - includes string combiner box (up to 5 strings) and PV cables. Does NOT
include roof or ground mounting components.

003 PVC-STRING-COM- Breakout junction box for solar PV connection into Easygrid units - utilises the Harting connection into 157.69 1.00 157.69 BREAKOUT-1 the Easygrid. Accomodates 1x 3core SWA cable connection from PV Combiner via SWA gland (SWA
cable and PV Combiner not included in this part number).

004 GEN-JCB-G017QX- JCB G17QX Generator - Canopy Set - Prime Power 13.2kVA / Standby 14.2kVA - 1500rpm - Single 8,168.67 1.00 8,168.67 1PH-230V Phase - 230v (765 KG)

005 GEN-BATT- GEN BATTERY CHARGER UPGRADE. 71.40 1.00 71.40 CHARGER Connection point to supply power to internal battey charger within generator 230v 6a
UPGRADE

006 EASYGRID-OPT-63A EASYGRID OPTION: 63A Plug and Coupler set for Easygrid 5000 and 10000 units (supplied loose, 106.00 1.00 106.00 -PLG/COUP does not include cable, cable to be quoted seperately)

A bit hard to copy and paste but the above was the quote they've received for £32,000 including VAT

<blockquote><cite>Posted By: Victorianeco</cite>The boss has a small holding and wants to run electric up to his new barn he's building.</blockquote>

I dont really understand why batteries and generators are being quoted?? 100 metres of 6mm SWA is a couple of hundred pounds. Add a small consumer unit, glands and a spark to connect up and your looking at £500 if he trenches the cable himself.

I would just put in a 32amp cable. If your main supply is not up to that load then you can always fit a 16A breaker for now. It's probably 10mm cable. I have about 50m supply in 6mm cable and I wish I had put 10mm in now as it drops a bit when charging EV at 32amp.
Find a local independent (but decent, up to spec) electrical contractor and check spec for requirements.
Dig the trench yourself(it's across a field, it's easy, just hire a digger for the day or two.
Put electrical cable and water in trench (diff depths, tape etc... check with electrician).
Bring up tails at each end in appropriate place and let plumber and electrician deal with them.

You can also put the cable in the duct before you bury it. The duct we used was supplied with a thin draw string. First thing we did was pull through 3/8" or 10mm polypropylene rope. Then the cable, then buried it. We pulled a second draw rope through with the cable so there would be one left in it just in case.

Perhaps also run a network cable to the barn? Probably needs to be a screened cable if in same trench as the mains cable.

Check the supply to the house cope with another significant load?

Posted By: CWattersYou can also put the cable in the duct before you bury it.

That's fine for the first time, but doesn't help if you want to replace the cable or pull through an additional one. And if you're not considering such things, why not run the armoured cable directly in the ground?

The duct we used was supplied with a thin draw string. First thing we did was pull through 3/8" or 10mm polypropylene rope. Then the cable, then buried it. We pulled a second draw rope through with the cable so there would be one left in it just in case.

It's very easy to blow a draw string through a duct with a shop vacuum cleaner. As you say, that is used to pull through a rope and that pulls through the cable and another rope. We taped the cable to the rope, to avoid any bulky knots that might have jammed.