Public foul gravity sewer directly under house help please

jojoxxx2001

Thanks everyone for the replies...Will definitely be doing more investigation around the position of the sewers.

We are unlikely to extend in our lifetime as we are downsizing...but we were definitely planning on converting the existing attached garage to a room. So interested to know if as it already exists are there any likely complications?
I suppose my main worry was whether to purchase "if" indeed it does happen to be under the house. More worried about potential costs if it leaks/cracks under a property and any potential resale problems for my kids.

Doozergirl

Section62 said:

GDB2222 said:

GrannyKate said:

Worth knowing where it is exactly because of potential future developments.  When we had our extension built 12 years ago the building inspector had quite a few conditions relating to the sewer if it stayed where it was but recommended the best course was to move it out of the new property line so it would be under the new patio not under the bungalow.  Cost about an extra £1000 I believe. 

You can do that with your own drains, but can you do it with a public sewer?

You can ask the sewerage undertaker to divert a public sewer - they may agree to allow you to do the work yourself, or may want to do the work and bill you for it.  In a few cases (mainly with major or trunk sewers) there isn't an option to divert.

But it is usually an expensive business, and on a domestic scale the costs can easily be out of all proportion to the value of the property.

On that plan, I don't think the sewer would need diverting for an extension.

Potentially a new inspection chamber if the existing one sits in the new building, but it's bread and butter stuff for a builder and doesn't add a lot. 

As long as it is not a major sewer, as you say. Isn't the type of sewer on the plan indicated by a colour key? 

jojoxxx2001

It's a mains sewer I believe....public foul 

Doozergirl

jojoxxx2001 said:

It's a mains sewer I believe....public foul 

That doesn't mean very much.  Anything that is shared is a public foul sewer, most are just 4" inch pipes like the one coming from your toilet and they go to the street.  Nothing much to worry about, other than considering what happens if you extend the house.   

If yours is a 4" pipe it wouldn't bother me in the slightest.  I'd rather have the shared sewer run front to back than side to side from a construction perspective.  

It's if they are larger, high pressure ones that you can't build over.  I've not yet come across one on any of our client's builds in 20 years.  Those are the sort you can't build over.  

jojoxxx2001

these are the maps that I have

jojoxxx2001

This is a larger area

jojoxxx2001

My husband has spoken to a friend of his who works in land buying and he seems to think they could be over 600ml

Section62

jojoxxx2001 said:

This is a larger area

"600mm CO" means the pipe is 600mm in diameter and made of concrete.  That is a large sewer - heading towards the size that may be used for a trunk sewer.  Likewise for "675mm CO".

Is the ground around the property a bit hilly?  The drainage from the close itself appears to go into the sewer in "***** Lane", rather than connecting directly to the larger pipe.  That could be due to an issue with a level difference, or it could be the pipe you are concerned about is trunk/strategic and one the sewerage undertaker doesn't want direct connections to.

With a manhole in the back garden of the property you should also check the deeds to see what access rights ST have - especially if any vehicular access has been built over.

Doozergirl

Right, so the "build over" people at Severn Trent are really helpful.  I would call them and ask them for advice. 

This looks like it could be a strategic sewer at 600mm which they may not agree to build over (despite having built over it).  

This is only a problem if you want to build, of course, but while you're on the phone you can ask them what it means for you in general. 

The sewer is the property of Severn Trent.  If something was wrong with it, it's their responsibility to fix it, there's no liability on you.  

I think it's always a good idea to have a CCTV survey of drains to check condition before anyone buys a house but I'd certainly recommend it in your case.  Ask the vendors to pay.  If there's nothing to worry about on the condition front, you're fine, it just the future building question. 

Grumpy_chap

I wonder whether that sewer location pre-dates the houses being built in Pinewood Close and the sewer was actually diverted before the road was constructed by the mapping information for the sewer never got updated.
Certainly, today, the developer would not be permitted to construct without diverting the sewer first.