Any idea what's caused these cracks?

[davidmiller]

I'll include some photos of cracks we have. There's one above a window that's on a side wall of the house. I only noticed it when stripping wallpaper off. There's also a fine crack on the ceiling just above which I'll hopefully show. And there's another fine one which is on the outside wall just below that window
I don't think I'd have been too bothered by any of them normally but the thing that's giving me runny stools is in a few days there's a side extension being built on that side and there's a padstone going into the wall and the new roof will be sitting onto the wall and the roof above this side of the house. And the plan is to remove the outside skin on that side to get some much needed extra space in the extension.
Any advice what to do please?

 

[Wayners]

When ground swells it moves and there is no weight under the window so it's first to move. Normal.

Dig out the loose above window and have a look