Not many rules apply here - been up more than 4 years

When I stuck my barn up it went about 4.2 metres 'cos
I didn't allow for the ridge pieces 
After about 6 years, a spiteful neighbour got me a visit from planning enforcement.

Others were complaining about their 22+ greyhounds

Over a nice cup of tea I showed the said officer my barn complete with my 1959 Austin FE Series 3 lorry.
It was declared to be OK having been up more than 4 years AND part of the enjoyment of our property

We only have 22 houses in our hamlet and I get on with them all.....
.....the old bugger with the greyhounds apologised before they moved