Does this require planning ?

I don't think you need planning permission for windows in the rear of the roof. Rooms need to comply with building regulations if used for anything other than storage. E.g. design of stairs, amount of headroom etc.

Either type of dormer in those photos require planning

My take would be a Section 5 request to the LA to be the first port of call as it could be argued that as they were there as 2 originally, the "streetscape", albeit to the rear, has not drastically changed to something different. No harm in asking and, at least if positive, you have it on record.

S.4.1.(h) development consisting of the carrying out of works for the maintenance,
improvement or other alteration of any structure, being works which affect
only the interior of the structure or which do not materially affect the external
appearance of the structure so as to render the appearance inconsistent with
the character of the structure or of neighbouring structures;

i wonder did the sun room need planning as it has a window to the fence side overlooking the neighbours