Hi Peter - yes we are stick building on site with the i-beams. We have made good progress erecting the frame, it is just that I have been a bit delayed setting up the blog due to everything else going on with the build. On the surface, it sounds similar to your self-build - I enjoyed reading your blog very much.
Our groundworkers did a simpler trick, but hid 100 tree stumps extracted when putting in the access, this went into our 'borrow pit' which was emptied of rock for our access and then refilled with the stumps and clay with turf put back on top. This resulted in no rock coming on site and no muckaway costs.