Building over sewer

Lollo2304

We purchased a house 2 years ago. We were aware at the time that there was a conservatory erected over the top of the gravity surface water sewer. There was an insurance policy in place to protect against any problems arising from this. After relayiing the floor in there it has become clear that not only was it erected over the top of the sewer without informing Severn Trent, there is also a man hole cover there.

On doing so research, Severn Trent will allow permission to build over sewers once permission has been sort providing tehre are no problems. However, they will not allow you to build over man hole covers. This was not shown as a cover on the water report provided to our solicitor (all man hole covers are shown with a 'dot').

We would like to knock down the conservatory and build a 2 story extension in an ideal world. I have already contacted the insurance company who will only talk to a solicitor. So it seems i need to pay a solicitor to ask teh insurance company to give us permission to talk with Severn Trent about building over the sewer.

Can anybody give me any advice as to whether this is a pointless exercise?? Does anyone have any direct experience to help or advice to give???

Thanks in advance.

tigeress289

I would think that as long as you provide a manhole cover,then I can se no problem. You can easily fit an internal double seal cover, which can be finished to suit most floor coverings. Trent water should give you advice on this. Your builder should also know this anyway.

keyfob

It depends on the category of the sewer.

If it proves to be a public sewer, you certainly will not be allowed to build over a manhole cover and in fact you might not be allowed to build over the sewer at all.

The usual rule with public sewers is that you are not allowed to build within 3m of a sewer without entering into a Building Over Agreement with the sewer authority.Severn Trent in your case.
You will then have to to take your foundations down below the invert level of the sewer.

There are many different types and sizes of sewer and the permission to build new them varies.

One way to find out if it is a public sewer is to phone Severn Trent and without telling them about your situation, ask them to look on their sewer maps to see if any public sewers are indicated.

If it trns out not to be a public sewer, you mat be able to divert the drain to allow you to do the building work yo want.

Lollo2304

It is a Public surface gravity sewer... i checked on the paperwork supplied from the solicitor. It has no manhole cover marked so we were not aware there was one until we changed the flooring in the conservatory. It wasn't declared to us even after our solicitors questioned it and ensured there was a insurance policy in place should a problem arise.

There is a 'rodding eye' in the garden which points down to where the sewer is.

The drain cover is only about 150cms from the wall of the house.

Is there any point in asking a solicitor to write to the insurance company to get permission to talk with Severn Trent??? Are they not going to give permission to build over and relocate the man hole????

keyfob

A public service gravity sewer doesn't mean anything. I have never come across that......ever.

You need to ask a solicitor, contact Severn Trent and ask them if you have a public sewer in your back garden (even if it is now inside your house).

Lollo2304

Sorry, replied quickly.

It's a Public surface water gravity sewer.

www
severntrentsearches.com
/LinkClick.aspx?fileticket=MOIsdBfe6lI%3d&tabid=431

It drains local surface water off roofs etc... not a foul sewer

keyfob

Makes no difference, if it's classed as a public sewer it could be surface water OR foul sewer.

Check with Severn Trent and you don't need to ask a solicitor in order to do this.

Lollo2304

Unfortunately i do need a solicitor.

If i speak with Severn Trent i will run the risk that they will find out about the conservatory already there. That will invalidate my insurance policy so if they make us take the conservatory down and pay a fine i will no longer be covered by the insurance.

When we bought the house we were led to believe it would be no problem building an extension but now we find a man hole cover and that changes everything!

ik1

I am really interested in this thread as I am in a similar boat. I will soon be completing on a house that has a foul sewer in the garden exactly next to the house where I would like to put an extension of 4m. Having spoken to a few different people including an architect, he assures me it is nothing to worry about as majority of the cases he deals with have a public sewer in the back garden. He said Severn Trent would give permission as long as you put concrete lintel over the pipe to protect. The sewer is 150mm and Severn Trent's website also suggests they will give permission.

Obviously your scenario is slightly different in that you already have a conservatory on it but as you will be knocking it down, you will have to have new foundations which you can build according to Severn Trents requirements.

warmhands.coldheart

Lollo2304 wrote: »

There was an insurance policy in place to protect against any problems arising from this. .

Get a solicitor and do the thing right. Will the insurance not cover any costs??

tigeress289

The title makes it sound more than it is. Have you got houses either side to start? The gravity, just means it has a fall on it. Sounds like your drain could connect to next doors in a run. But you need to check how the drains run either side of you first. You will only be able to move the manhole, if the drain runs outside of your extension. A more detailed description of the layout of the inside of the manhole,would be a great help, to give us a better idea or a photo.
cheers