Council enforcing 20cm setback on loft

The problem with the pre-2008 rules was that you had to be adept at working out volumes. Presumably the powers that be then felt it would be easier just keeping to simple overall dimensions.
(though personally I always believed the 3m rear extension limit to be too small. When allowing for the thickness of the wall, it doesn't give much extra space; 4m would have been more reasonable).

I remember thinking when the 'prior approval for larger extensions' came in, it would have been much simpler to just increase the PD depth restrictions by 1 metre to 4 metres and 5 metres. That would have been so much simpler than what we are dealing with now.

The overall volume limit did often make things complicated. Maybe the current regs aren't too bad but it would simplify things alot to get rid of the prior approval for larger extensions, and also remove the restrictions on materials and the 200mm set back rule, as these all seem to cause problems as many people to not seem to be aware of / fully understand the implications of these restrictions.

Remember that PD isn't there to let people do what they would want easily, it's there to reduce the workload on the planning department by pre approving what development should be uncontroversial enough to not require human attention. The prior approval scheme is somewhere in the middle of the two extremes.
Presumably the irritating aspects of the rules were added in response to previous design issues in order to better tread the line between what people want (space) and what is good design (keeping a hint of the original shape of the roof)

200mm is the length from my wrist to my finger-tips.
I do hope this "dispute" is not in my borough and being paid for by my council tax.
Technically it would nice for a length of narrow gutter collect the rain lashing down onto the slates and so-called-balcony doors.
If the wounded pride of building control/planning needs to be satisfied, it does not look that difficult to create a slate skirt into the new mini gutter, preferably making sure there is a PVC eaves tray to catch any drips!