Moving an inspection cover

[Househuntmadness]

We have viewed a house to buy with a kitchen extension which was done in 2009. Rather than reroute the drain, it looks like the previous owners (before the current sellers) built the extension over it. Meaning there is an inspection cover in the kitchen. It’s blended into the floor so aesthetically ok.

our concern is if it ever backs up, it could flood the kitchen.

Question is, is it possible to reroute now and how much disruption are we talking? Would it be ripping up the entire extension or just the floor and replacing the kitchen?

I think that theoretically you should be able to do the rerouting from outside but I guess it depends where the pipe needs to be rerouted? You also might need a party wall agreement with your neighbours depending on how deep you need to dig down and if the rerouting would need to involve digging in their gardens then it might be a total non starter.

Unless the extension was done on an incredibly tight, immovable budget I would be asking why the drain was not moved at the time?
If it was feasible back then, I think just about everyone would prefer a cover to be outside rather than inside (it does happen but usually for very good reasons) and they would have had it done while all the upheaval was going on.

Investigate but be prepared for disappointment or a hefty quote.

This would be a big fat no for me.

If this is a foul water drain the idea of the whole kitchen getting flooded out with crap. Just no.

Also if the water company wants to access to unblock surely they are going to drag all their tools covered in nasty stuff out of your kitchen.