Thanks Maniacquilter2, yep got the construction process and I have a very basic quilt design program which I use to plot my pattern and size etc but it doesn't have a fabric estimation capability; hence my scrabbling around on sheets and sheets of paper and wearing my calculator batteries to within an inch of their little lives trying to work out my fabric requirements and being gobsmacked that by my calculations I need so much extra fabric for smaller blocks to make the same size quilt.