If your house is built anything like mine Andy then you may find there aren't as many noggins as you think, almost all of the walls in my house have no horizontal noggins in place, this means I have been able to knock a small hole behind the skirting and drop a wire down from top to bottom with minimal (but still quite a lot!) of effort.

Forget about feeding cables up the exterior walls, this is way harder than you think. One option could be to run on the outside of the house using black tube trunking, I have used that here for some electrical runs and it seems easy to fit and is cheap.

In your house, I would suggest that getting things into the loft is key, and then drop down the interior studs. Always put more cable in than you expect to use, ie sky plus to every room! pulling up floorboards in a newbuild is stupidly difficult and is best avoided.

Anyway you run new wires requires planning and lots of hard work. You also need the help of a good cable monkey, feeding wires is not something you can do on your own, although SWMBO probably isn't the best person

Another tip, it is one of those jobs that always takes 3 times longer than it will think it will, even when you think you have already factored in 3 times more than you thought you first thought. I spent about a week running in 24 CAT5 points and co-ax to each room. And bear in mind I did used to do that for my living, and I still used trunking for the major run to the loft space from the "server room"

Cheers

Cris.