Planning permission/Building regulations apply?

leafy211

Please advise if planning permission is required, or building regulations would apply if I was to build an extension to the brick shed, which is attached to the back of the mid-terraced property.  There is currently no door direct from inside the house to the shed.  The extension will be kept at the same height as the current shed, and less than 3 metres long.   The distance to the back wall of the garden will be about 5 metres. 
The neighbour is not happy as the wall of the extension will mean part of her view in the garden will be the bricks of the extension wall instead of daylight, so I want to ensure everything is above board.  Would i need to prettify anything from her side of the fence/her view (eg paint the bricks white to match the fence which the extension will run along)?

DevilDamo

Is the brick shed original or a previous extension? Assume it’s only single skin too?

leafy211

Hi DD
Yes part of original building and only single skin.