I also happen to be building a large workshop/store/whatever at the bottom of the garden (you may have noticed).
I plan to install (or have installed) the stove in the middle of the front of the building. This would make the flue approximately 4m from each of the three surrounding fences.
I have looked at: http://www.stovesonline.co.uk/flue-outlet-height.html and from this it looks as though the flue outlet needs to be at least 600mm above the highest point of the roof. Given that I am constrained to a heaight of 2.5m for the highest point of the roof this would give a flue outlet height of 3.1m minimum. In old money, this is around 10' off the ground. This would be at the level of the first floor of the surrounding houses (including ours).
All well and good, but is there a minimum overall height for a flue? 10' is not that much higher than the average washing line, and in our case we have a neighbour 2 gardens away who has a washing line on a huge pole - it is a bit like hoisting signal flags when the fleet comes into port :-)
I suppose the situation is similar to a flat roofed bungalow (although you can't build those now) near to a double storey house.
I think that if I go to about 4m off the ground then I should be O.K. - assuming that the smoke rises at a reasonable rate - but I was wondering if there was any absolute rule about minimum height for a chimney? I don't want to end up with 6m or more of pipe sticking up above the roof! Google has not so far been my friend. Any stove installers out there?