Get that shed built and finished ASAP

Following your "New Workshop" post with interest.
Did a similar thing about 20 years ago and it's still going strong.
Basic low 'pole barn' - 36'x20' in 3 bays with a big 6 roof. All recycled

A neighbour (now gone) had a problem with others and their 20+ greyhound breeding business.
We came home from holiday to a postcard from Planning Enforcement.
The complaint was that I had built the shed without planning and running business from it

At that time I had a classic 1959 Austin FE Series 3 lorry in there. Immaculate and used on rallies etc.
I was concerned because it had gone over the 4m rule by about 200mm.
The nice lady from Planning Enforcement said, " Don't worry I can see that it part of the enjoyment of your property."
Q "What about the height?" R "I am not even going to measure it. I can see it's just over 4m, but has been up over 4 years, so it's exempt"
That was a big relief