M
mantissa
That's good stuff - although the 200mm from the ridge requirement is often confused as covering the distance to the roof edge - which it doesn't. I like the 3 times the height off the plane of the roof suggestion which is in that thread - there seems to be real reason for it (wind loading). Also linked from that thread is the amazing story from Dorset which seems to make a nonsense of wanting to do it right. I went to my local planning office today for an informal consultation and all they were able to stipulate was the less than 200mm off the plane of the roof and down from the ridge.
