Extension built over public foul sewer pipe - do we walk away from the purchase?

tizzzr

Hello everyone, any advice would be grateful,

The house we are purchasing has a public foul sewer running under a kitchen extension and along the back gardens of the row of houses. The extension had planning permission passed in 1999 and it must have been built sometime between then and 2008. There is no building regulations completion certificate according to the sellers. There is no build over agreement with the water company as they became effective in 2011 according to the sellers. Although I have read that pre 1937 built houses (which this one is), shared drains were all made public and would still have needed a build over agreement for the extension? There is no drain cover within the property for access.

The concern is, if the pipe needs replacing or repairing the water company will either bring down the kitchen extension or dig up the kitchen from inside. Further if they unearth the foundations and don't like what they see could they demand we rectify the foundations to protect the pipe as it is without a certificate? What are the chances of the water company running a new trench around the extension for us? Reading up, I am not encouraged that indemnity insurance would protect us much from this. Aaaaaaargrhrrghrr! 

Thank you

user1977

tizzzr said:

The concern is, if the pipe needs replacing or repairing the water company will either bring down the kitchen extension or dig up the kitchen from inside.

Or put the new pipe somewhere else, if that's going to be easier?

Section62

tizzzr said:

There is no build over agreement with the water company as they became effective in 2011 according to the sellers. Although I have read that pre 1937 built houses (which this one is), shared drains were all made public and would still have needed a build over agreement for the extension? There is no drain cover within the property for access.

Yes, the vendors are wrong (and maybe are/were wrong about other aspects of this building work).  Buildover agreements aren't limited to post-2011 works.

Drains and sewers which served more than one property before 1937, became public sewers known as Section 24 sewers. (and still are).

The odds are that there will be a manhole somewhere within this property, and if it isn't visible then there is a good chance it has been buried under the extension.

If there's an alternative to having a building demolished to get access to a sewer the sewerage undertaker will certainly consider that, but it isn't always possible.

However, (other than pulling out of the purchase) you can't really make any decisions without knowing more about the drainage system and what condition it is in.  For that you need a CCTV drainage survey, but arranged so they can get access to the sewer from a neighbouring property.  Expect it to cost a few hundred pounds. Check to make sure any company used is independent, and not a service company of the sewerage undertaker - otherwise there is a risk any indemnity policy would be invalidated because the owners of the sewer were made aware of the issue.

You also need to understand what happened with building regs - although it is probably past enforcement, that won't be much comfort to you if the building is substandard.

aoleks

If only you knew what’s under that extension. A survey wil reveal that.

It’s extremely rare for water authorities to demolish an extension to replace a pipe, it’s cheaper/easier to divert it. Having said that, you need some reassurance that it’s all ok.

I would get indemnity insurance to cover my costs in case of.

Section62

aoleks said:

It’s extremely rare for water authorities to demolish an extension to replace a pipe, it’s cheaper/easier to divert it.

It still depends on the circumstances, and who is doing the paying.

aoleks said:

I would get indemnity insurance to cover my costs in case of.

What costs does sewer build-over indemnity insurance cover?

Can the policy be used to force the sewerage undertaker to accept the (rebuilt) extension affecting the public sewer?

Slinky

We had our extension built in 2007 and had a build over agreement then so your vendor is wrong with the 2011 date.

tizzzr

Slinky said:

We had our extension built in 2007 and had a build over agreement then so your vendor is wrong with the 2011 date.

This is interesting, I wonder if your property is pre 1937? Our solicitor seems to think if the extension is pre 2011, then the agreement is not required.

Section62

tizzzr said:

Slinky said:

We had our extension built in 2007 and had a build over agreement then so your vendor is wrong with the 2011 date.

This is interesting, I wonder if your property is pre 1937? Our solicitor seems to think if the extension is pre 2011, then the agreement is not required.

There's a common misconception that build over agreements didn't exist before 2011.  Those people are confused by the fact 2011 represents the year in which most shared drains which weren't already public sewers became public sewers.  The mistake they make is in thinking prior to 2011 there were no public sewers in people's gardens, and therefore no approval (buildover agreement) would have been needed.

If the pipes/drains weren't public sewers when the extension was built (before 2011) then your solicitor would be right.

But if this property is pre-1937 and has shared drainage then it is a public sewer and your solicitor is wrong.

There are also cases where pipes/drains became public sewers between 1937 and 2011 - hence me bolding "weren't" above, because the cases where no buildover agreement was required are a specific category of pipes/drains, there is no universality pre-2011.

Slinky

tizzzr said:

Slinky said:

We had our extension built in 2007 and had a build over agreement then so your vendor is wrong with the 2011 date.

This is interesting, I wonder if your property is pre 1937? Our solicitor seems to think if the extension is pre 2011, then the agreement is not required.

No our house was built in the 1970s. The buildover agreement came about as a result of what was found about the street drainage when we put in our building control application. Initially the water company rejected our plans and told us we couldn't buildover, but we dug down and found the main street sewer would be at a 45% angle to the corner of the extension, the footings were dug below the level of the sewer and it was all protected with shuttering and gravel to taken any pressure off the sewer.

Woolsery

tizzzr said:

Slinky said:

We had our extension built in 2007 and had a build over agreement then so your vendor is wrong with the 2011 date.

This is interesting, I wonder if your property is pre 1937? Our solicitor seems to think if the extension is pre 2011, then the agreement is not required.

Our last house was built in 1939. We needed a build-over agreement with Bath City Council in 1989 to go over a public 150mm sewer at 2m down. Believe me, if we hadn't needed it, we'd not have carried out the considerable engineering work.