Hi,

 

im considering running some drainage under the existing foundations. The SE has specified local underpinning if I wanted to do this. Will this cause complications later on for insurance, mortgage or selling? Will I have to say it’s been underpinned, even if it wasn’t due to subsidence? 
 

I’m worried that, through trying to do the right thing for my drainage situation, I’m about to make things worse for myself in the long run! 
 

 

This is just a terminology issue.

 

That's not underpinning ... that is forming a backfilled opening for a service penetration.

 

There, problem solved.

 

Underpinning is, correctly, a method to improve the load bearing capacity of foundation by increasing the foundation depth, width or both. You're not doing that, so it isn't underpinning. It just looks like underpinning.