From highest natural ground to highest point on the roof actually comes out less than 2.4M as the ground slopes a bit. After looking at it closely, though not actually measuring it yet, I am confident that from lowest ground to highest point would still measure less than 2.5M.
Looks like I'm in the clear. 2.4 metres is the highest point on the roof. Total footprint is a little over 11 square metres, while the usable floor area is obviously rather less.
I apologise in advance for not having the exact measurements to hand, but hopefully one of you knowledgeable people will be able to answer my question anyway.
I have a mid terrace house. We recently had a breeze block shed built at the end of the back garden, and is separate from the house...