External render issue

Hi folks. Hoping someone could give some advice.

Currently in the process of buying a 2nd hand house, its approx 27 years old.

Surveyor checked it out and has flagged an issue with the external plastering on side and rear wall. It was patched badly and is bubbling on the outside. The patchwork covers a large portion of external wall. There is also a small amount of damp evident on the inside wall. He reckons the original render fell away and thats when dampness got in, then it was patched up very badly with new render and has suggested hiring a plasterer to have a closer look.

I'm wondering if this is going to be a massive and expensive job that will cause major issues or is this fixable with an experienced plasterer involved ?

Thanks a mil.