...if I have understood permitted development rights correctly....
you can just have a builder start building an extension.. (with relevant sign off by the building control people at all the stages obviously).
It seems mental doesn't it...but this is how I am understanding all the reading I'm doing. That LDCs are not mandatory but you can have one if you want. I would phone the council but they have suspended all phone advice because of COVID.
Has anyone here built their extension (conforming to permitted development) and gone ahead without getting one of those LDCs? There must be loads of you...?!