Guidance needed: Structural Engineer's Survey

TBorg

Surveyor has recommended that I get a Structural Engineer to ascertain whether the house I'm buying is seeing any ongoing movement/subsidence. As the sellers had foundations underpinned about 40years ago. 

It is a 4bed,2 bath detached house, about 2000 sq ft. Any idea how much it will cost me? Should I get just the foundations inspected or the entire house? I have asked for quotations from few engineers but really have no clue whats the rough fair price in south London. Google search tells me estimates of £500-£2500 (not very useful!). Anything else that I should know before proceeding with this survey? Thanks very much for helping this first time overwhelmed buyer.

Doozergirl

What evidence is there of potentially ongoing movement?   It would be pretty unusual for something that had already been underpinned to move! 

Have you spoken to the sellers about the reasons for the underpinning? Hot summer of 1976 and shrinkable clay?  

You could pay a structural engineer for a walk around with you in the first instance.  They cost about £100 an hour, give or take.  It's just a bit unusual that there's no mention of a specific issue? 

TBorg

Doozergirl said:

#1 Have you spoken to the sellers about the reasons for the underpinning? Hot summer of 1976 and shrinkable clay?  

...

#2 It's just a bit unusual that there's no mention of a specific issue? 

#1: Sellers said underpinning was precautionary. But they claimed insurance on it, so I'm not sure it was indeed precautionary. Extension they did was 10 years after the underpinning, so that can't be the reason either. 

#2: Surveyor doesn't think it is ongoing but recommended a structural engineer to confirm. His best guess is that subsidence was due to leaky drains. But sellers don't have any documents whatsoever and neither does council. If they had a report saying underpinning was done to appropriate standards, I wouldn't have to worry.

tacpot12

You might keep the cost down if you make it clear to the engineer that you only want their opinion, not a full-blown report. If they can summarise their findings into a sentence or two, this will save them time, and if you are buying, you only need to know if there is movement or not (assuming you won't buy if there is any ongoing movement). 

weeg

Honestly, I wouldn't bother. If it's been underpinned further movement is very unlikely. Wanna post exactly what the report says?

FWIW, I'm an SE who does house inspections. But I work in Scotland where subsidence is less common (different soils from London). I'd be charging you ~£150 for a visual inspection with verbal report/ follow up email. But, again, not London.