Urgent! Shared party wall and sharing drains...

[Runningoutofusernames]

NOT the most exciting, but quite an expensive question!

Summary: Is a future saving of £4.5k that could be 1-2 years away plus 10cm extra space (due to sharing a wall) worth having neighbours access their drains via a manhole on our side of the fence? Are there legal implications e.g. easements that might affect value, or be a pain? Need to decide by tomorrow morning!

Details: We bought a house at the same time as our (lovely) neighbours.

Given we both want to extend the backs, and to the same length, we'd discussed sharing a wall, to give us each a bit more space and share the cost. Even though we would be extending 6-12 months ahead of them, we'd benefit from the space, and they would only have to pay when/if they extended. All good!

HOWEVER, it turns out we both need to move manholes next to the dividing line. We''d factored this in, but for them it is an additional £4k, and they are saying this is more than they can afford right now, even to save £5-7k down the line (they would be paying less than 50% of the shared wall costs).

Our building control says they could save £500 by using our manhole and they are keen.

We are a bit concerned that this gives that property an easement over ours, and also frankly, if 4k is not affordable, then realistically how soon can they do a 5 x 6m rear extension (they did say it now might be more than a year). We've had multiple quotes on the work so are pretty confident the numbers are realistic, and think that maybe they'd underestimated costs.

It's all been very friendly so far, so want to keep it that way and resolve this quickly and simply!

I wouldn't. Honestly, you don't want neighbours to have to access your property to maintain anything on theirs if you can help it. You may get on with / trust these current neighbours, but what happens when you fall out over building works? Or when they move out and a**holes move in? Or people continually block the drain with fat / nappies / wipes and don't rush to get it cleared; you'll have raw sewage seeping all over your garden.

Can you build the wall without moving their drain?

I'm not sure I understand what is being proposed here, but I do know that when more than one household feeds into the same drains you have what is classed as a public sewer and therefore need to consult the sewerage company about manholes etc as they effectively own the public portion of the sewer. They may well agree to the idea but will need to be consulted first before commencing any building work. HTH

Thank you! Basically, we each have our own drains now, but they don't want to pay the full £4k to replace theirs, so would plug into ours to save money (on the basis that we end up saving money by sharing a wall). I just worry that this is all sounding like a fair bit of risk up front for an uncertain payback.

AJP - we can build a wall solely for us without moving their drain, but if we're doing a shared wall both drains need to move.

Thanks majorclanger and lindylove, this complication is what I'm a bit afraid of!

I had a similar thing with a cheeky neighbour installing services - pipes, gutters, drains etc on the outside wall of his house, his boundary - and therefore technically overhanging my garden. I agreed because I wanted to be accommodating and kind and make his building work cheaper / easier - and I massively regretted it. It caused nothing but issues - him needing access for continual tweaks and maintenance, and a conveyancing nightmare when I came to sell. Better not to muddy the waters and keep things separate, I say, even if it does cost you money.

I agree with above poster - I think you would need to consult with your water company on this as it would now be a public sewer.

On that basis i would just go ahead and do the build without the shared wall. It sounds like you and neighbour have differing views about timetable. They intend to extend "one day" . You want to do it now. I cant see what you gain except that people will think you nice.