Well after talking on board all your comments I have built my pig accommodation and opted for,.....
My 10 x 8 pig shed on a hard standing with a wood floor,
My 6 x 8 Pig shed in the wood on a frame of sleepers without a floor but with dried bracken as a base topped with sheep fleeces and covered in straw.
My 4 x 5 Pig shelter in the pasture on a sand base without a floor but with lots of straw.
We will see how we go on through the coming months and what this winter throws our way. The floored buildings on the hard standing allow me to bring the pigs off the land in the event of a heavy snowfall and keep them warm and dry. Hopefully the others will stay dry but if not I have the option of slotting in some pallets and boarding them over.
I do hope they like the smell of creosote
[size=78%] [/size]