Sewage pipe in back garden, was planning to extend

[newbie1234567]

Hi All,

Just looking for some advice if anyone knows much about this. I'm a first time buyer, and we've had the searches back from the solicitor. It looks as though there is a sewage pipe/drain in the back garden very close to the house, under the area which we were planning to extend over. The map from the search shows the combined pipe in our garden which belongs to Thames water, which runs through next door's garden, but that part is not owned by Thames water. The pipe doesn't appear to connect to anything else- just runs through both our gardens.

Does anyone have any idea what this could mean? Does it mean we would have to move the pipe? and If so, any idea of costs? Thinking that we might be best off abandoning this, because no extension would be a show stopper for us.

Heres a picture of the offending pipe! The house with the red line in the back garden.

THanks

 

[freddiemercurystwin]

I don't quite understand which house you are? Its less of an issue if you're the one with the blue bit? And unless there's a manhole under on red and that's the house you own then it shouldn't be a showstopper? So which house is yours and where are the manholes?

 

[Notch7]

Hi All,

Just looking for some advice if anyone knows much about this. I'm a first time buyer, and we've had the searches back from the solicitor. It looks as though there is a sewage pipe/drain in the back garden very close to the house, under the area which we were planning to extend over. The map from the search shows the combined pipe in our garden which belongs to Thames water, which runs through next door's garden, but that part is not owned by Thames water. The pipe doesn't appear to connect to anything else- just runs through both our gardens.

Does anyone have any idea what this could mean? Does it mean we would have to move the pipe? and If so, any idea of costs? Thinking that we might be best off abandoning this, because no extension would be a show stopper for us.

Heres a picture of the offending pipe! The house with the red line in the back garden.

THanks

If the start of the drain run is the house with foul run marked blue, then when it goes across the boundary it becomes an adopted drain. As its a row of semis it looks like it runs across the back of a few houses.

To build you will require a build over agreement. If you go to the Thames water site there is a section for developer services and there are downloads for a build over agreement. Unfortunately, the only way to be sure, is to apply for an agreement and see if you get it.

If you email them a drawing and all the info, they will prob get back to you in a day or so and tell you the likely outcome.

You need to know invert level, direction of flow, acess -ie where the drain can be rodded, type of pipe.

Note that your foundations will need to be 150mm below invert.

You may need to get CCTV done, Thames water organise it.

 

[freddiemercurystwin]

If the start of the drain run is the house with foul run marked blue, then when it goes across the boundary it becomes an adopted drain. As its a row of semis it looks like it runs across the back of a few houses.

To build you will require a build over agreement. If you go to the Thames water site there is a section for developer services and there are downloads for a build over agreement. Unfortunately, the only way to be sure, is to apply for an agreement and see if you get it.

If you email them a drawing and all the info, they will prob get back to you in a day or so and tell you the likely outcome.

You need to know invert level, direction of flow, acess -ie where the drain can be rodded, type of pipe.

Note that your foundations will need to be 150mm below invert.

You may need to get CCTV done, Thames water organise it.

The rules are pretty clear, you can either get a buildover or you can't.

 

[newbie1234567]

That does make sense I think. Just weird how the pipe seems to go nowhere! Will contact thames and see what they say. Thank you both.

 

[newbie1234567]

I don't quite understand which house you are? Its less of an issue if you're the one with the blue bit? And unless there's a manhole under on red and that's the house you own then it shouldn't be a showstopper? So which house is yours and where are the manholes?

Ours is the one with the red bit and unfortunately the current owners have paving slabs down so we never noticed any manhole covers- maybe they are underneath. Will have to check I think!

 

[newbie1234567]

If the start of the drain run is the house with foul run marked blue, then when it goes across the boundary it becomes an adopted drain. As its a row of semis it looks like it runs across the back of a few houses.

To build you will require a build over agreement. If you go to the Thames water site there is a section for developer services and there are downloads for a build over agreement. Unfortunately, the only way to be sure, is to apply for an agreement and see if you get it.

If you email them a drawing and all the info, they will prob get back to you in a day or so and tell you the likely outcome.

You need to know invert level, direction of flow, acess -ie where the drain can be rodded, type of pipe.

Note that your foundations will need to be 150mm below invert.

You may need to get CCTV done, Thames water organise it.

Thanks Notch7. I think it would be safer to re route the pipe though rather than build over it and hope they never want access, even if they do agree to it...or have i got that wrong?

 

[Notch7]

Thanks Notch7. I think it would be safer to re route the pipe though rather than build over it and hope they never want access, even if they do agree to it...or have i got that wrong?

A build over agreement is still needed. It should really be called a build near to agreement as it is needed if building within 3.0m

Re routing isnt that easy, if you increase the pipe length you then have to reduce the fall which could be below the minimum. And Thames water would require a more expensive application and drawing.

Given you only have 1 other house involved, my guess is you should be okay. Ive found Thames water quite helpful to deal with regarding build over agreements, but they decide whether or not to allow a build over so its entirely in their hands.

From memory, a standard build over application is £350, so if your buying depends on it and you want the house, then you could apply and wait for the decision before exchanging contracts.

 

[newbie1234567]

A build over agreement is still needed. It should really be called a build near to agreement as it is needed if building within 3.0m

Re routing isnt that easy, if you increase the pipe length you then have to reduce the fall which could be below the minimum. And Thames water would require a more expensive application and drawing.

Given you only have 1 other house involved, my guess is you should be okay. Ive found Thames water quite helpful to deal with regarding build over agreements, but they decide whether or not to allow a build over so its entirely in their hands.

From memory, a standard build over application is £350, so if your buying depends on it and you want the house, then you could apply and wait for the decision before exchanging contracts.

Interesting. We will have a chat with them and submit an application and see what happens. Thanks alot for your help

 

[Ian H]

I wouldn't reroute it, I'd build over it but renew it if it's shallow enough.

The pipe will carry on and have more connections onto it.

 

[newbie1234567]

I wouldn't reroute it, I'd build over it but renew it if it's shallow enough.

The pipe will carry on and have more connections onto it.

isn't that really risky though? what if thames water wanted access to it?

 

[Ian H]

They would access it from the upstream manhole same as they do now.

 

[endecotp]

Just weird how the pipe seems to go nowhere!

I suspect that Thames have "forgotten about" the next downstream bit. It will either continue through the next back gardens or turn and run between the houses to the road at some point.

I wonder whether this short stretch has been re-surveyed recently for some reason. Maybe the current or a recent owner had the drains surveyed? Maybe they considered a build-over but didn't go ahead? (Does that sound plausible to those who know more about drains than I do?)

You might like perhaps ask them. Also, ask whether they've hidden any manholes under the patio.

 

[newbie1234567]

I suspect that Thames have "forgotten about" the next downstream bit. It will either continue through the next back gardens or turn and run between the houses to the road at some point.

I wonder whether this short stretch has been re-surveyed recently for some reason. Maybe the current or a recent owner had the drains surveyed? Maybe they considered a build-over but didn't go ahead? (Does that sound plausible to those who know more about drains than I do?)

You might like perhaps ask them. Also, ask whether they've hidden any manholes under the patio.

Thats a good point, I'll find out. Thanks