Southern Water Build Over Agreement

[Xmania]

Hi Everyone, I am doing a rear extension and have appointed a Building Regs (BR) consultant via my builder.

Unfortunately my builder for whatever reason did not alert the BR consultant when he started work.

On his visit, the BR consultant told me that I need a Build Over Agreement from Southern Water as the extension will sit on top of a sewer.

My builder says that he was going to dig down on the side to create another access point to replace the one that has been covered by the extension.

I am very stress now cos my builder has obviously done things back to front.

My question is what are my chances of getting an approval from Southern Water for this build over and has anyone gotten this approval before?

Many thanks

Usually it’s pretty easy to get them. But they usually want a manhole chamber before and after where the extension sits.

So even if there was only 1 before they will usually want 2 assuming your extension is directly over a large portion of the sewer

Also there are different processes for different sizes sewers. 160mm below and above to what I can remember. You’ll also have to bridge sewer pipe if your foundations need to go lower.

All waterboards are different usually you can ring them and probe them for answers.

Squirreltamer, thanks for you reply.

I have been looking at the Southern Water form and it is very technical and my builder don't seem very competent in filling it so I will approach a surveyor to complete and submit the form for me.

It's only paperwork stage and the cost is already about £2k. I wonder how much the works are going to cost. The not knowing is really scary.

Sounds like you have done such job. Do you remember how much it costs you in the end?

Many thanks again

Sorry just logged on.

Not entirely saw it was about £500 for the waterboard side, basically permission and a drawing. And as I was already digging it all out not much in terms of labour and materials were pretty cheap only a few 100. Probably an extra 1.5/2k including the rip off piece of paper.

Hello Im sorry to be a pain and piggy back from your message but i just wondered how far you have got in this process and how helpful/difficult southern water have been. We are due to buy a house and have realised that sewage pipes runs along the garden and we are planning and extension. Any advice/help/tips or reassurance would be gladly recieved. Thanks

@xmania

Hi, my first builder was terrible and the cause of all the problems and concerns with this and every build job in the house. We gutted the house and did 5 ensuites plus this extension.

But my second builder was excellent.

Everything went smoothly and SW was happy.

So long as your builder can be trusted, and has done such work before, it will go smoothly. Everything with SW is really just a case of paperwork and paying SW lots of money.

It’s only since 2011 that the majority of private sewers came under public/shared ownership and therefore requiring consent to build near or over a sewer. Because of that, water companies do not go out of their way to make lives difficult and refuse applications.

If you’re planning an extension and are looking to appoint an architect/designer, they should take care of any statutory applications.

Thank you @DevilDamo and @Xmania you have put my mind at rest a little bit. I don’t mind an extra bit of tick boxing if extending isn’t totally unviable as we are buying the property for the sole purpose of extending.

You'll probably have to get a camera survey from a Water Board approved firm as well.

Just out of curiosity @Xmania did you build over 6m of pipes or not.

Thanks

Francesca

Not sure if I understood you correctly. The sewage pipes run horizontally across under my extension which is 4m wide.

The original sewage access point will end up under my extension so my builder moved the access point by about 2+m so the access point now sits just on the side of my extension. If the water company need to rod any blockages, they will be able to

Thank you that’s makes perfect sense. Thanks.