Planning permission is not normally required for work to maintain foundations though if you live in a listed building you should check with your local planning authority.
If you need to underpin all or part of the foundations to your building, the building regulations will apply.
The regulations specifically define this as 'building work'.
The appropriate requirements will be applied to ensure that the underpinning will stabilise the movement of the building.
Particular regard will need to be given to the effect on any sewers and drains near the work.
Learn more about building regulations for underpinning.