Kitchen extension - public sewer issue - advice please!

[Wigeon]

We are planning a small kitchen extension, for which we don't need planning permission. The planned extension is right by a manhole in the back garden, and so will probably go over a sewer at the back of our house. The exact classification of the sewer appears to have some relevance as to whether we need to submit full plans to the building regs people, or if we can just do a building notice. Despite speaking to both the Building Regs person at the Council, and to Thames Water, we are more confused than before, with very unclear advice from both.

I am particularly confused about whether the issue is: whether the sewer is on the "public map of sewers" or whether it's an "ex-Section 24 sewer" (these do not appear to be the same as each other).

I know this is a rather specific question, but I figure since loads of people on here have extended their houses, surely someone had come across it before!

Can you explain it all clearly to me?! It's driving me mad as we can't progress the extension plans until we resolve this!

Thanks very much.

We have similar situation, we want to extend and manhole cover in the way & we have shared drains with neighbours. Thames Water (I spoke to Insight dept, and the Development Solutions dept) were very helpful and confirmed as it is private sewer we can basically do what we want with it. So we're planning on building over it but insert a new access point to allow for jetting should there ever be block.

I would call them again as they will have a report of all public sewers, you can pay for a copy of this report. So it should be straightforward to confirm if your drain is public or private. You can take it from there onwards. HTH

Hi vbus - thanks very much for replying and sorry not to acknowledge your post sooner! We are having trouble establishing from either Thames Water or the local council whether the sewer is public or private - both of them say to ask the other! - although in the last phone call with one of them it was looking like it was public. You would have though both of them should have the map of sewers! Oh well. I think we are finally getting somewhere though...

Thanks again for your reply.

Ring Thames Water back up and tell them the sewer keeps bloacking and you would liek a CCTV survey to see if there'sa partial collapse. They will very quickly decide if its public and they should do it or private and tell you to do it!

How old is your house? If its pre-1937 and the sewer serves 2 or more houses then its a section 24 (public) sewer.

A public (non section 24 sewer) is normally out in the road/footpath.

I don't really understand how there is a possibilty it could be an ex section 24 - unless it used to serve 2 houses but only serves one now I suppose? Don't know.

You shouldn't have to pay to find this information out and Thames should know the answer. I used to work for a water board but up North so maybe different in London with regards to paying.

Thanks VivaLeBeaver! It had occured to me that if I was trying to get Thames Water to spend any money on the drainage they would find out pretty quickly whether they were liable for it or not!

I don't understand all this "ex" section 24 business but this leaflet from Thames Water bangs on about it.

The confusing thing about our house is that its between a row of Victorian terraces (ie definitely pre-1937) but a bomb fell on our house and the house next door during the Second World War, and so ours and next door actually date from the 1950s. And so it's difficult to know if the drainage dates from the Victorian terrace which used to be on the site of our house, or whether they re-did the sewer in the 1950s when the current house was built.

And there is a manhole cover which straddles the boundary between us and the (1950s) house next door, but some bright spark thought it was a good idea to build a brick wall on top of it, with a kind of little bridge on top over the sewer, supported by a single brick, and so we are bit worried that if we move the single brick (to look in the manhole to see what direction the drain goes - ie straight to the street, or to next door) the wall will fall down.

So it would be a whole bunch simpler if Thames Water, or the council, could just blimming tell us whether the sewer is public or private!!

That was way too much about our sewerage! Gah!

OK, What they call a ex section 24 sewer is what I would call a section 24 sewer. Though its ten years since I last worked as a sewerage engineer so I've probably forgotten the right terminology!

However I would say if your house was built after 1937, even if built on the site of a pre 1937 sewer then your connecting bit probably won't be a ex section 24 sewer. So from your property wall there will be a pipe that goes from your loo and sinks, that pipe will run into a bigger pipe that all the houses connect to. Now that bigger pipe sounds to me like it would be an ex section 24 sewer. As long as there is more than one pre 1937 house that connects into that sewer.

Someone from Thamnes water should come out and look at it if they can't work it out by records. I used to get asked to do that sometimes, had to go and have a look and make a decision.

We have a communal sewer running along the back of our terraced house and are planning to build extension over it. Thames Water said I'd need to apply for and pay for a "build over agreement" I think it was called. Takes several months apparently and have to be able to show them the structural engineer's support calculations to ensure the extension won't damage the drain. None of our neighbours did this, they just had a separate small ridding point put in further down their gardens and had no trouble getting building regs sign off.