Thames Water Built Over Agreement

earlgrey13

Dear all,

We are in the process of buying a new home in North West London and have recently discovered that the rear extension of the house may have been built over or within 3 meters of a public sewer. The vendors did not obtain Thames Water built over agreement back when the extension was built, though Building Control certificate was issued at the time. However, the vendors have been great and agreed to do a retrospective agreement with TW.

May I please kindly ask OPs who may have experiences on this specific issue a couple of questions:

1) Understood the retrospective survey/agreement may include a CCTV inspection and some paperwork - does Thames Water usually issue retrospective certificate once these are done? Usually how long would that take (e.g. to hear back) please? We were told up to 21 days but not sure if usually it really takes this long?

2) Once the built over agreement is in place, may we (as buyers of the property) assume that everything is good for this specific extension, from Thames Water perspective? In other words, even if the pipe below may have issues in future, the water company will not come and tear the extended building down?

Thanks in advance for your kind help.

Section62

earlgrey13 said:

1) Understood the retrospective survey/agreement may include a CCTV inspection and some paperwork - does Thames Water usually issue retrospective certificate once these are done? Usually how long would that take (e.g. to hear back) please? We were told up to 21 days but not sure if usually it really takes this long?

It depends what they find - if the pipe is unsuitable to be built over, or is in poor condition, they might want further work done before completion of a build over agreement.

The time taken depends on how busy they are, along with any additional Covid related restrictions.  There is a lot of building work currently being done, so TW might be busier than usual.

earlgrey13 said:

2) Once the built over agreement is in place, may we (as buyers of the property) assume that everything is good for this specific extension, from Thames Water perspective? In other words, even if the pipe below may have issues in future, the water company will not come and tear the extended building down?

No, that would be an unsafe assumption.

Sewage undertakers have statutory powers to do work in private land, which include demolishing buildings if necessary.  Having an existing sewer under the property increases the risk of work needing to be done, which can't be done without removing the building.

However, in normal circumstances the sewage undertaker has to compensate the property owner and/or arrange reinstatement or rebuilding.

So on the whole it is more likely if there was a problem with a sewer under a building, the undertaker would look for an alternative such as laying a new sewer in a different position, or using a 'no dig' technique to carry out a repair.

But you should get your solicitor to check the details of the buildover agreement carefully to see how future liability might be different from the standard legal position. They might seek to limit the compensation payable as a quid pro quo for the building work being done without their prior consent.

earlgrey13

Section62 said:

earlgrey13 said:

1) Understood the retrospective survey/agreement may include a CCTV inspection and some paperwork - does Thames Water usually issue retrospective certificate once these are done? Usually how long would that take (e.g. to hear back) please? We were told up to 21 days but not sure if usually it really takes this long?

It depends what they find - if the pipe is unsuitable to be built over, or is in poor condition, they might want further work done before completion of a build over agreement.

The time taken depends on how busy they are, along with any additional Covid related restrictions.  There is a lot of building work currently being done, so TW might be busier than usual.

earlgrey13 said:

2) Once the built over agreement is in place, may we (as buyers of the property) assume that everything is good for this specific extension, from Thames Water perspective? In other words, even if the pipe below may have issues in future, the water company will not come and tear the extended building down?

No, that would be an unsafe assumption.

Sewage undertakers have statutory powers to do work in private land, which include demolishing buildings if necessary.  Having an existing sewer under the property increases the risk of work needing to be done, which can't be done without removing the building.

However, in normal circumstances the sewage undertaker has to compensate the property owner and/or arrange reinstatement or rebuilding.

So on the whole it is more likely if there was a problem with a sewer under a building, the undertaker would look for an alternative such as laying a new sewer in a different position, or using a 'no dig' technique to carry out a repair.

But you should get your solicitor to check the details of the buildover agreement carefully to see how future liability might be different from the standard legal position. They might seek to limit the compensation payable as a quid pro quo for the building work being done without their prior consent.

Thanks a lot