Build Over Agreement with Southern Water

My builder started my rear extension without informing the building regs (BR) officer. I do not know why especially when he was the one who recommended that I go with this BR officer.

On his visit, the BR told me I need a Build Over Agreement from Southern Water. I have submitted the application now.

Southern Water is now asking for detailed drawings of the foundation design, and details of existing/proposed plans, including any known existing drainage arrangements.

My builder is not helpful in providing these information and he also hasn’t turn up for a meeting with BR.

The extension is a shell at the moment but you won’t be able to see the foundation unless you dig around it.

Can someone tell me who to approach to get the drawings and plans done? I really don’t know where to start.

Also I will need to create a new manhole in the side garden. I am very worried about the cost now, as the application fees alone is already £1k. How much does such works usually cost and what are the chances that I will need to tear down the extension?

Architectural technician. Deduct the costs from the builder.

Pray that the idiot has actually done the foundations correctly and bridged over the sewer pipe properly.

What about planning permission?

Woody, thanks so much for your response.

I’ll go look for Architectural Technician.

As it is a single storey rear extension less than 6m from the original of the house, it is under Certificate of Lawful Development which I have applied for with the council and still waiting for their approval.

I honestly do pray that the foundation is done properly. As to bridging the pipe, I am not hopeful cos I think it’s just cement over it. This is a real nightmare. I thought I’ve paid for a BR to come in so things can be done properly.

Woody, I am really grateful for your reply, giving me some direction.

I think you might be missing some insulation too.

From the photo there is some kind of bridge as you can see the block immediately above the drain has been cut and the DPC steps up. Dig out that bit of soil and have a look.

The drain is quite shallow so it should be reasonably straightforward to have bridged the drain with concrete lintels. Mind you I don't think I'd be happy leaving that old salt glazed pipe under my floor. I'd be inclined to replace it with plastic for peace of mind.

Wessex101,
Thanks for your reassurance.

I can’t dig that part out now as that was an old photo. By the time I knew the mess I am in, the builder had already poured the concrete.

This is how it looks now and it is only at this stage that I pulled the plug and stopped all work.

The experience I've had with southern water is they arent at all helpful, unlike Thames which have really helpful engineers.

generally foundations need to be 150mm below invert level (inside bottom of pipe) and it looks quite shallow so hopefully ok.

My concern is that the public drain appears to go under the neighbours outbuilding, which could be awkward.

Southern water may want a CCTV of the drain run, before and after. And they may want the run replaced.

Every builder knows the first inspection required is foundations before concrete is poured. What is your ground like and do you have any nearby trees? Both influence foundation depth -I wonder what decision process the builder used to decide the depth.

Either your builder is inexperienced or incompetent -possibly he forgot a notice needed to be applied for and once the job started he wanted to keep his guys busy -mind you I thought a building notice only required 24hours notice?

Im guessing building regs drawings werent done, so a full building regs application wasnt done and its being done under a building notice?

Did the building inspector say what he wanted in order to approve the foundation? -apart from the drain issue?

I hope you havent paid him too much, because if there is a lot of remedial work, he might walk away........

Magtan said:

Wessex101,
Thanks for your reassurance.

I can’t dig that part out now as that was an old photo. By the time I knew the mess I am in, the builder had already poured the concrete.

This is how it looks now and it is only at this stage that I pulled the plug and stopped all work.

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That must be a very thin slab, you can still clearly see the bottom of the cut block and the step in the DPC. Also where is that new drain going? From the previous picture it looked like there was a manhole under those buckets but there's no sign of it in the later photos.

Notch7, I genuinely do fear how difficult it will be to work with SW. I’ve googled around and many people seem to have experience with Thames and not SW. It is also a more costly application with SW compared to other water companies and I see that as an indication that SW will be awkward to work with.

The SW lady on the phone was very understanding but it really is the engineers that I worry about.

With regards to foundations having to be 150mm below invert level, is there anyway to check this now that the cement has been poured.

In the event that current builder does not provide any information about what he has done e.g. depth of foundation, how he bridge the pipe etc, and I get another builder to take over, is there any chance to get the information as oppose to tearing the whole extension down?

BR wants to know the damp course measures, depth of foundation, soil condition, depth of public sewer.

I have paid the builder more than 80% of the works. Now that I am aware of all these problems, I know definitely that I have overpaid him. He was asking me for another £4k to be paid today. I am sure he didn’t turn up to meet the BR today because I didn’t pay that £4k.

Yes there is a manhole where the buckets are and a manhole in the neighbour’s garden. Their manhole is in a location that is accessible and not under their outbuilding.

There are no nearby trees. The ground is brickearth over chalk.

Yes building regs drawings weren’t done. I didn’t realise these were needed. I kept asking for them as I needed some drawings for application of Lawful development certificate (LDC) for the extension and he just kept saying there is no need for them so I got someone to do elevation drawings which were required for the LDC.

I did not know there is a difference between full BR application and building notice.

I have a feeling he deliberately did not inform BR. I do not know why though as this BR officer is recommended by him. So I am very concern he has cut corners somewhere and just wanted to send photos to the BR for sign off.


Wessex101,
The concrete slab is 120mm and it covers over the original manhole. He still needs to pour celotex and screed over the cement.


The builder’s plan is to dig a new manhole in the side garden.

The pipe is for the kitchen sink and joins into the old man hole.

Magtan said:

I have paid the builder more than 80% of the works.

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Golden rule is never pay a builder more than the value of the work complete. You have paid 80% and the job is only 40% complete.

Is this a legitimate job with a bonafide builder? Does he have insurance you can potentially claim against? If not, and if he don't cooperate, then you may need to involve Trading Standards at the council.

And btw, what if you don't get the certificate of lawfullness from the council? Work should not have started until planning permission was secured.

Magtan said:

, is there any chance to get the information as oppose to tearing the whole extension down?

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I dont know, its not easy. Building inspectors like to see the trench to see the layers of soil and they like to see a nice flat bottom to the trench. Chalk is generaly good ground with a good load bearing capacity and with trees nearby, maybe the BI might sign off the founds. Holes will need to be dug down to expose the bottom of the foundation. Goodness knows about the drain issue.

Magtan said:

I have paid the builder more than 80% of the works

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Im sorry to hear that, its what I suspected A blockwork in / out jobbie doesnt cost much to get upto plate height and even roof if flat.........its an excuse to get stage payments well beyond work measure.

^woody^ said:

Golden rule is never pay a builder more than the value of the work complete. You have paid 80% and the job is only 40% complete.

Is this a legitimate job with a bonafide builder? Does he have insurance you can potentially claim against? If not, and if he don't cooperate, then you may need to involve Trading Standards at the council.

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Woody, I spoke to the builder this evening and he asked me on what basis am I judging the amount of works done. I told him it’s obvious just by looking at the place!

He was recommended by the friend who is using him and it seems like that friend is having issues with the builder as well but not as serious as mine. On hindsight, I didn’t check him out enough. He said he has fire regulation certification, CDM and sound like he knows what he is talking about. I view a couple of his jobs and it looked alright.

I thought LDC is just a paperwork assurance as it is permitted development since extension falls under 6m.

Of course now knowing about the sewer situation, it complicates matter and you are right that I should have gotten approval prior to work commencing.

It took me a long time to figure out where/who I can engage to get the elevation drawings done. All along the builder just said it’s fine. The application can be done anytime.

When I eventually submitted the LDC application, I ended up having to pay £100 more as it is a retrospective application because work had already started.

I have stopped all works now and been having many sleepless nights.

I genuinely thought I have paid a builder and a BR person so things will be done properly. They know more than me as this is what they do day in day out.

Magtan said:

He said he has fire regulation certification, CDM and sound like he knows what he is talking about.

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He talks the talk, shame he doesnt wslk the walk.

Magtan said:

I spoke to the builder this evening and he asked me on what basis am I judging the amount of works done

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Well hes done foundation, slab, blockwork, prob flat roof and 1st fix electrics - its nowhere near 80%

Magtan said:

This is how it looks now and it is only at this stage that I pulled the plug and stopped all work.

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The wiring is wrong. If the builder is self certifying that then I would be additionally concerned.