Anthony & Kirley, The shed I am building could never be used as a layout, it would have bikes, the golf clubs, a lawnmower and god knows what else thrown in there after 6mts. I think the attic is eventually the way to go.
Thanks for all the advise so far from everyone and for those with layouts in the attic does the cold or dampness affect the layouts or locos? Or in the summer does the heat?
Skinner75 & Glenderg Ill take your advice on the ridged insulation between the rafters and plasterboard over. I might need to knock a hole in the gable wall and install a vent for the hot summer evenings.
But first things first, I got some 15mm plywood today Buck-shee pre cut in 500mm x 1350mm strips and all I need now is a bit of 2” x 2” or 2” x 3” to construct a frame. Once construction commences Ill post some photos.