I shouldn't think so.

To do it properly they would. It will need new drains, services footings, the lot. Best get rid of it all as it will prevent issues later on and will be cheaper in the long run.

My guess is that the terrace is laid on ash and/or colliery spoil which naturally has nic occurring with in it. Most of Yorkshire is built on colliery spoil and the nic is not particularly soluble so is not a problem unless it has to be removed. As the spoil will contain nic and other contaminants it will incur a higher level of land tax when it’s taken to a license tip so will be expensive to remove.

As to the stability I wasn’t an engineer but if it’s loose it may be possible to stabilize it by pressure grouting but that’s costly as well so either way it’s an expensive job.

I meant in the short term, I can't see it all being done at once, I assume thats what MC means by Phase 1 etc.

Sorry, misunderstood.