I've managed to convince mum into getting sky, and she's happy for me to pay extra for multi room if it is actually possible. Mainly because my room is the sleepout! Now, from what I know they basically run a seperate cable from the dish to the second decoder? Would there be a way to circumvent this? Or would it be possible to have a cable run under the ground to my sleepout? It's no more than 5M from the house.
I have myski hd. Briefly I had a second myski decoder. The sky installer upgraded my lnb to a quad one so both boxes worked independent from one another with out any problems. Currently I have myski using 2 cables off the dish from one side of the lnb, on the other side I have a single feed to a freeview box. I would imagine if you don't have myski, as long as you have a dual lnb you can run 2 seprate feeds. Not sure if sky would run a splitter of the dish to 2 sky boxes. Not sure either why you would want to circumvent running the second cable.
The installer will probably want to go with the most basic and easiest install possible. It certainly won't include underground cabling. I got sky installed about a week ago and I wanted the cable run from the dish to my central patch cupboard and then out to the tv with a joiner in the patch cupboard. The installer looked skeptically at me but was quite happy when I said I was happy to run all the cables under the house while we was up on the roof mounting the dish.
So...If you could bury a pvc conduit with a draw wire in it then when the install gets there it will be nice and easy for him.
Ons the side, an easy way to get a draw wire through if you forget, or if you already have a pipe, is cotton thread with a ball of paper and use a vacuum cleaner to suck it through the pipe. Then use the cotton thread to pull through a thin rope, then step up to a larger rope.
I would imagine the installer would not be too keen. They get paid little for the job. But like others said if you get everything in place with a draw wire then it should be lots easier to negociate. As long as it is not a seperate unit (i.e. no cooking facilities).
Connect the pipes together with all the socket ends pointing in the same direction and draw the cable through in the opposite so that the cable does not get stuck on the edge of the non-socket ends.