Done some rethinking and some replanning and put some tent pegs and string in the garden where this is likely to go (not so much a garden as a unkempt undergrowth behind the trees). Reckon I can get 6.5 x 4m external which is 6 x 3.5 internal and I can keep it to 2.5m high by putting the door in the end and better utilising the space. So here is plan B in Sketchup this time...

Give me a continuous run of 6m of workbench with the lathe and grinder at the end, lots more windows and therefore light and room to put the bike trainer up when I can't get out and ride... and i could make it 0.5m narrower if need be (but I dont want to). Will make it a single pitch, 2.5m at the front sloping to 2.25m at the back (top of pic)

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