Neighbour building an extension

redser7

Hi,
A neighbour called in over Christmas and told us they are building a kitchen extension, works starts in the middle of January. It is a small enough job.
We are semi detached. Common enough layout, L shaped with the kitchens already extended out. The 'gaps' in the layouts are next to each other, separated by a seven foot wall. They want to square off their kitchen.
The builder recommended they knock the separating garden wall, put in a proper foundation and rebuild the wall as a party wall. They said it will be an advantage for us if we decide to do the same thing in the future as this part of the work will be done already for us. Indeed it is something we would like to do when the money is there.
I'm having a quick meeting with the builder tomorrow so he can talk me through what he will do that will affect us during construction. Is there anything I should ask him or be concerned about regarding this new party wall seeing as we will want to build on to it later ourselves?
If the neighbours one goes well we might even use the same builder.
Thanks, sorry for long-winded post.

Qualitymark

Won't you have to clarify ownership of the party wall?

DoomZ

Insurance and safety....will he be responsible on your side too.

redser7

Qualitymark wrote: »

Won't you have to clarify ownership of the party wall?

I have no idea. I know nothing about this area. I would have assumed that party wall means shared ownership, no? Thanks for enlightening me. Never had to consider such things before.

moleyv

Just make it clear if they damage anything your side that they will have to fix/replace it as soon as reasonably possible. This includes any damage to sewer/drainage or other utilities that may exist.

And regarding insurance, a quick written confirmation that they will be covered and responsible for the works should be enough.

Discuss things like wrecking and muddying up your grass/shrubs/flowers. Although to be fair, most of the work should happen from their side when its just a wall.

As stated already, clarifying who owns the wall etc. who owns the bit of land it will be built on can save some headaches down the road. at least ye can be clear now.

redser7

moleyv wrote: »

Just make it clear if they damage anything your side that they will have to fix/replace it as soon as reasonably possible. This includes any damage to sewer/drainage or other utilities that may exist.

And regarding insurance, a quick written confirmation that they will be covered and responsible for the works should be enough.

Discuss things like wrecking and muddying up your grass/shrubs/flowers. Although to be fair, most of the work should happen from their side when its just a wall.

As stated already, clarifying who owns the wall etc. who owns the bit of land it will be built on can save some headaches down the road. at least ye can be clear now.

Thanks for that! How would I establish ownership of the party wall? To the eye the existing wall, made of blocks laid flat, runs smack bang down the middle of the properties. I 'assume' that gives common ownership and we have an equal responsibility to eachother to respect that.

jeepers101

What about the finish on your side? You'll want some neat blockwork or plastered.

moleyv

redser7 wrote:

Thanks for that! How would I establish ownership of the party wall? To the eye the existing wall, made of blocks laid flat, runs smack bang down the middle of the properties. I 'assume' that gives common ownership and we have an equal responsibility to eachother to respect that.

Yes that is possible. Either they survey it using survey equip and come to a determination and you take their word for it, or you have it surveyed using the landholding map for yourself to be sure. That is always a bit difficult if it is borderline ie. how wide is a line drawn onto a map.

That is why it is easier to discuss it now. It may seem being awkward at first to your neighbour but it seems you have a reasonably good relationship and just sell it as being clear and avoiding the question in the future.

If ye come to the conclusion it is shared. maybe a small contract would be appropriate to iron out things like access for maintenance to the wall.

In that context, just remember your neighbour may not always be the same person.

redser7

jeepers101 wrote: »

What about the finish on your side? You'll want some neat blockwork or plastered.

They offered to finish it anyway we like. Rendered, painted,whatever. They seem to be very reasonable about the whole thing but I just want to leave no stone unturned as you hear about a lot of disputes regarding party walls and like I said we may extend ourselves later on.
Thanks!

redser7

moleyv wrote: »

Yes that is possible. Either they survey it using survey equip and come to a determination and you take their word for it, or you have it surveyed using the landholding map for yourself to be sure. That is always a bit difficult if it is borderline ie. how wide is a line drawn onto a map.

That is why it is easier to discuss it now. It may seem being awkward at first to your neighbour but it seems you have a reasonably good relationship and just sell it as being clear and avoiding the question in the future.

If ye come to the conclusion it is shared. maybe a small contract would be appropriate to iron out things like access for maintenance to the wall.

In that context, just remember your neighbour may not always be the same person.

Good points, thanks a lot. As they are extending I think they'll be here for the long-haul like ourselves, but you're right, you never know.

moleyv

Walls normally need to be plastered and capped to be planning compliant. Unless a planning permission states otherwise.

It is good to know who is responsible for the wall.

If there was a freak storm tonight and knocked the wall down. who would pay for it to be rebuilt. one property owner or both.

But regarding services etc. even if the builder says there are none there. Dont take his word for it, make sure they take responsibility. Even if there are none mapped or on drawings it doesnt mean there isn't some old thing there.

Teyla Emmagan

Do they need planning permission or is their site big enough?

Also think about water running off their new roof. You want to make sure all the guttering is in place to take it down their side, and that your property won't end up taking any of their spill off. I mention this as a neighbour asked a few years ago if I would let them use my down pipe for the water from their new extension and now I have this poxy pipe out the back that dribbles water at odd times and attracts hordes of flies. Their builder hooked it up to the overflow from their tank I think as well as their new roof. So if they ask for any favours say no!

redser7

It doesn't need planning permission, it's too small. Thanks for advice, good point. I'll be keeping a close eye during construction.

moleyv

Teyla Emmagan wrote:

Do they need planning permission or is their site big enough?

Planning permission for an extension has very little to do with the size of their site.

To build an exempted extension, the only limitation regarding site size is that there will still be more than 25 square metres left in their rear garden. There are other restriction s on the size, height and separation distances in order to be exempt. But that isnt really the discussion for this thread.

Regarding surface water from roof. It should be directed to the storm drains if any, or an on site soakaway.

Gumbo

redser7 wrote: »

Hi,
A neighbour called in over Christmas and told us they are building a kitchen extension, works starts in the middle of January. It is a small enough job.
We are semi detached. Common enough layout, L shaped with the kitchens already extended out. The 'gaps' in the layouts are next to each other, separated by a seven foot wall. They want to square off their kitchen.
The builder recommended they knock the separating garden wall, put in a proper foundation and rebuild the wall as a party wall. They said it will be an advantage for us if we decide to do the same thing in the future as this part of the work will be done already for us. Indeed it is something we would like to do when the money is there.
I'm having a quick meeting with the builder tomorrow so he can talk me through what he will do that will affect us during construction. Is there anything I should ask him or be concerned about regarding this new party wall seeing as we will want to build on to it later ourselves?
If the neighbours one goes well we might even use the same builder.
Thanks, sorry for long-winded post.

My recommendations, although not exhaustive.

Meet builder and come up with a list of items and both of you sign and date a copy each. for you, your neighbour and the builder. The items may or may not include :

• There should be no issue with party wall ownership here, you both own it, the new wall should be built centered on the property line and thus this will continue into the future.
• Make sure the builder agrees to fix any damage on your side as soon as reasonably possible.
• agree a finish on your side of the wall (rendered/dashed/painted).
• Insist that the new wall is solid blockwork on its flat, insist on this as if you go to build in the future, you may find that what you want to do cannot be supported safely on another form of construction (Cavity Blocks for example). Ive recently been involved in a project that this exact thing happened and thus meant that the original party wall was useless and the home owner had to step his extension into his property to progress. Using a solid block detail ensures you can build using this same wall in the future.
• take photos of the new party wall going up. when you want to build and a builder or Engineer asks about the wall, it takes the second guessing out of the calculations. you are able to show him that its a solid wall.
• for the length of the structure, it will need to be a parapet wall, capped to their side with a valley for their rain water kept on their side. you can mirror this detail if you go to build in the future on your side.

Qualitymark

Maybe talk to a solicitor.

When my neighbours built an extension they told me they weren't legally allowed to build it out to the centre of the party wall; they said they had to build it something like six or nine inches back.

**This isn't legal advice. Talk to a lawyer.**

BryanF

redser7 wrote: »

Thanks for that! How would I establish ownership of the party wall? To the eye the existing wall, made of blocks laid flat, runs smack bang down the middle of the properties. I 'assume' that gives common ownership and we have an equal responsibility to eachother to respect that.

Removing boundary to build extension all sounds quiet reasonable and is imo typically best practice. I would expect that your neighbour's structural Engineer would provide you with a Structrual cert

redser7

Thanks a million Kceire, great points. Especially the last one. Was trying to imagine how the roof and gutter would work from both sides on what is a relatively narrow wall. Would it be something like figure 38 in this article ...

http://chestofbooks.com/architecture/Building-Construction-V3/48-Parapet-Gutters.html#.VKZ3myusUms

Cheers

redser7

BryanF wrote: »

Removing boundary to build extension all sounds quiet reasonable and is imo typically best practice. I would expect that your neighbour's structural Engineer would provide you with a Structrual cert

Thanks again, I'll add this to the list.

Gumbo

redser7 wrote: »

Thanks a million Kceire, great points. Especially the last one. Was trying to imagine how the roof and gutter would work from both sides on what is a relatively narrow wall. Would it be something like figure 38 in this article ...

http://chestofbooks.com/architecture/Building-Construction-V3/48-Parapet-Gutters.html#.VKZ3myusUms

Cheers

yes, pretty much.

martinn123

All depend on the shape, of the new extension roof.

You mention a Kitchen Extension, and the ''New Area'' enclosing the space between Kitchen and Boundary.

What shape roof, is on the Kitchen, ? If it's a Lean To, they may just want to extend the Lean To, over the New Area, this will have a different configuration to the sketch you posted.

If the Kitchen has an ''A '' frame roof, it will be designed differently.

See if you can get a sketch of what is proposed, and post.

The Foundations for the New Wall, typically, may be wider than the wall, as such do they extend further onto your side, if so what are the implications, Shrubbery, Path, etc, on your side.

I seem to remember a post in a similar thread, which mentioned ''Fire Regulations'' regarding the shared wall, perhaps some of the Professionals here can comment, if my memory is correct.

Gumbo

martinn123 wrote: »

I seem to remember a post in a similar thread, which mentioned ''Fire Regulations'' regarding the shared wall, perhaps some of the Professionals here can comment, if my memory is correct.

The shared wall, if constructed correctly will offer adeqaute fire separation.
My advice of 215mm solid blockwork on its flat, 100mm insulated plasterboard followed by skim coat plaster and paint will be sufficient. This also offers structural ability to be used in the future on the opposite side.

Getting back to the fire end, it should be noted that the builder should attached a wall plate to the block wall and attach the roof rafters to that wall plate to avoid anything penetrating a party wall, even though its not a party wall until the OP builds himself.

the_syco

Top of the roof is an important bit; any overhang at all will create problems for you at a later stage.

NOTHING should be on your side. No guttering, etc, as otherwise where'll it go when you decide to build.

kceire wrote: »

• for the length of the structure, it will need to be a parapet wall, capped to their side with a valley for their rain water kept on their side. you can mirror this detail if you go to build in the future on your side.

This. Insist on it, actually, as some builders will just install a gutter on your side which will cause massive problems at a later date should you ever do your own kitchen, because as stated above there may be different people living there when you decide to put your kitchen in.

BryanF

kceire wrote: »

My advice of 215mm solid blockwork on its flat, 100mm insulated plasterboard followed by skim coat plaster and paint will be sufficient. .

this poor quality, lazy construction but not the OP's problem in this case. people extending (using blockwork that is) should insulate in a block work cavity or externally. 100mm drylining will cause a due-point inside the blockwork, this has been covered to death on Boards so ill leave it there.

redser7

Lots of great information, thanks everyone. I'm feeling much better armed to talk to the builder when he comes round. Even if it is just to fire questions at him to see how he responds.

Gumbo

BryanF wrote: »

this poor quality, lazy construction but not the OP's problem in this case. people extending (using blockwork that is) should insulate in a block work cavity or externally. 100mm drylining will cause a due-point inside the blockwork, this has been covered to death on Boards so ill leave it there.

Can that be done though?
Can a typical cavity construction detail be done properly and be then used as a boundary wall and then be used in the future by the neighbour? Genuine question.

BryanF

kceire wrote: »

Can that be done though?
Can a typical cavity construction detail be done properly and be then used as a boundary wall and then be used in the future by the neighbour? Genuine question.

If you know there is going to be an external wall there... I would not specify that construction or stand over it

Gumbo

BryanF wrote: »

If you know there is going to be an external wall there... I would not specify that construction or stand over it

What would you specify in this situation Bryan?

redser7

If I can add a question - the neighbour said the builder will finish our side of the wall however we like? What would you suggest seeing as we might build on it later?
Thanks again

Aard

redser7 wrote: »

Lots of great information, thanks everyone. I'm feeling much better armed to talk to the builder when he comes round. Even if it is just to fire questions at him to see how he responds.

It is good that you are informing yourself. If you appear as though you know exactly what youre talking about, your neighbour and/or the builder will be less likely to try to pull a fast one, for example overhang guttering.

BryanF

kceire wrote: »

What would you specify in this situation Bryan?

215 (or suitable 150) block party wall,100 insulated PIR cavity (or 150 pumped) 100 internal Aerated block

redser7 wrote: »

If I can add a question - the neighbour said the builder will finish our side of the wall however we like? What would you suggest seeing as we might build on it later?
Thanks again

Standard smooth Plaster, maybe leaving a cm of DPC out at the plinth

redser7

BryanF wrote: »

215 (or suitable 150) block party wall,100 insulated PIR cavity (or 150 pumped) 100 internal Aerated block



Standard smooth Plaster, maybe leaving a cm of DPC out at the plinth

Thanks again!

Gumbo

redser7 wrote: »

If I can add a question - the neighbour said the builder will finish our side of the wall however we like? What would you suggest seeing as we might build on it later?
Thanks again

The finish will not affect its structural capability for future use. The builder is asking if you want dash, rendered or painted finish. Dash or render would be my only option.

Gumbo

BryanF wrote: »

215 (or suitable 150) block party wall,100 insulated PIR cavity (or 150 pumped) 100 internal Aerated block



Standard smooth Plaster, maybe leaving a cm of DPC out at the plinth

Ok I get you now. That's a nice detail. So use the solid block as the centre line. Then put the cavity on the neighbours side. The OP can mirror this in the future too if he likes. Can this work at parapet level then ok?

BryanF

kceire wrote: »

Ok I get you now. That's a nice detail. So use the solid block as the centre line. Then put the cavity on the neighbours side. The OP can mirror this in the future too if he likes. Can this work at parapet level then ok?

Yes

Gumbo

BryanF wrote: »

Yes

The solid block can continue up and form the parapet and capping.
If you get a minute I'd politely ask if you could sketch that so the OP can show the builder the section he wants.

BryanF

kceire wrote: »

The solid block can continue up and form the parapet and capping.
If you get a minute I'd politely ask if you could sketch that so the OP can show the builder the section he wants.

When OP comes to build (if they build) their extension will make it an internal party wall? So with the greatest respect, its not the OP's problem how their neighbour chooses to build their extension, (once the party wall is suitably built, as outlined above). And I'm not about to spend my time doing the neighbours detailed drawings for them. Good night.

redser7

Thanks folks for all the varied feedback, much appreciated. I think I have enough good advice for time being
Cheers

slimjimmc

BryanF wrote: »

When OP comes to build (if they build) their extension will make it an internal party wall? So with the greatest respect, its not the OP's problem how their neighbour chooses to build their extension, (once the party wall is suitably built, as outlined above). And I'm not about to spend my time doing the neighbours detailed drawings for them. Good night.

I'm not well up on the technicalities but if the OP is serious about a future extension of his own would it be a good idea for both parties to agree to extend the footings now (at OP's cost) or can he do it later if he builds?

Qualitymark

Footings?

slimjimmc

Qualitymark wrote: »

Footings?

Foundations.

BryanF

slimjimmc wrote: »

I'm not well up on the technicalities but if the OP is serious about a future extension of his own would it be a good idea for both parties to agree to extend the footings now (at OP's cost) or can he do it later if he builds?

The party wall (block on flat) foundations would be designed to be sufficient to suit both extensions. That was taken for granted in the OP first post.

Gumbo

slimjimmc wrote: »

I'm not well up on the technicalities but if the OP is serious about a future extension of his own would it be a good idea for both parties to agree to extend the footings now (at OP's cost) or can he do it later if he builds?

There would be no need to to be honest. The foundation taking the new party wall should be sufficient for both extensions. If the OP wanted to pre lay foundations now he would have to dig acros his back and then he is stuck with that layout for future work.

Get the party wall correct now would be the best thing to do now IMO.

antiskeptic

redser7 wrote: »

Good points, thanks a lot. As they are extending I think they'll be here for the long-haul like ourselves, but you're right, you never know.

I don't know if these points have been raised yet:

- if you're going to use this wall for your own extension in the future, would you want to push your extension out further than them? If so have them build the party wall out to the extent you need so that you can link to it easily rather than having to nail on extra which is structurally messy

- ensure their dealing with rainwater on the party side of their extension takes account of your future extension - ideally being positioned in such a way that you can insert your roof and drain into the party gutter (which should be sized to cope with rain water from both your extensions (and whatever might lead from the main roof onto these extensions)

- when they build the party wall it will likely be twin leaf insulated - that is to say, they'll construct two slim walls with a cavity of perhaps 100mm between them, with insulation board in the cavity attached to the wall nearest them. This means the outer leaf, i.e. the one you'll be looking at when they are finished is uninsulated. If you extend, you'll have to insulate that wall with drylining which is a bit of a bodge and will take up space on your side of the wall. Better to have them do some kind of full cavity fill insulation so that you don't have to insulated later on.

If they are going cheapo cavity block/drylining the that will force you into drylining your side come the time, which takes up more space than would twin leaf/full fill insulation (full fill now meaning you don't have to pay for insulation of that wall when you build )

- would you envisage building a two storey extension, in which case the party wall, if being used as a structural wall, would need to be designed for that load as opposed to a single storey structure. It's not a big deal cost-wise for your neighbour at this stage and perhaps it's something you could have included now in any case so as to future proof in the event you want to sell your own house with that option open to the purchaser. If two storey a consideration for you then again, ensure their roof is constructed in such a way as to allow you to extend the party wall upwards without problem.

redser7

Thanks again for the additional info, a lot to think about

Gumbo

antiskeptic wrote: »

I don't know if these points have been raised yet:

- if you're going to use this wall for your own extension in the future, would you want to push your extension out further than them? If so have them build the party wall out to the extent you need so that you can link to it easily rather than having to nail on extra which is structurally messy

- ensure their dealing with rainwater on the party side of their extension takes account of your future extension - ideally being positioned in such a way that you can insert your roof and drain into the party gutter (which should be sized to cope with rain water from both your extensions (and whatever might lead from the main roof onto these extensions)

- when they build the party wall it will likely be twin leaf insulated - that is to say, they'll construct two slim walls with a cavity of perhaps 100mm between them, with insulation board in the cavity attached to the wall nearest them. This means the outer leaf, i.e. the one you'll be looking at when they are finished is uninsulated. If you extend, you'll have to insulate that wall with drylining which is a bit of a bodge and will take up space on your side of the wall. Better to have them do some kind of full cavity fill insulation so that you don't have to insulated later on.

If they are going cheapo cavity block/drylining the that will force you into drylining your side come the time, which takes up more space than would twin leaf/full fill insulation (full fill now meaning you don't have to pay for insulation of that wall when you build )

- would you envisage building a two storey extension, in which case the party wall, if being used as a structural wall, would need to be designed for that load as opposed to a single storey structure. It's not a big deal cost-wise for your neighbour at this stage and perhaps it's something you could have included now in any case so as to future proof in the event you want to sell your own house with that option open to the purchaser. If two storey a consideration for you then again, ensure their roof is constructed in such a way as to allow you to extend the party wall upwards without problem.

I see a few issues with your advice here.

1. The OP will have to deal with his drainage on his side of the boundary. There is no way he should connect the drainage to his neighbours valley gutter in the future. He would open a whole new can of works there. The neighbour will build a valley on their side of the parapet and this the OP will construct a valley on his side when the time comes.

2. The neighbour cannot do the "twin leaf" as you describe as to do so would mean they would have to construct it fully on their side of the boundary. Then the OP will have to construct a new wall on his side in the future. The only way to do the part wall is a sold block down the centre line constructed up to form a parapet. In my opinion of course. The. With or can then detail their side with whatever build up they want and the OP can detail their side in the future in what they want without affecting the structural element of the wall. I think Bryan's section sounds good if the space is there but I would use a 215 solid on the flat instead of the 150mm block.

antiskeptic

kceire wrote: »

I see a few issues with your advice here.

My preparedness to bow to the advice of kceire should be noted by the OP

1. The OP will have to deal with his drainage on his side of the boundary. There is no way he should connect the drainage to his neighbours valley gutter in the future. He would open a whole new can of works there. The neighbour will build a valley on their side of the parapet and this the OP will construct a valley on his side when the time comes.

All fair enough if the neighbour is intent on a parapet-style construction.

2. The neighbour cannot do the "twin leaf" as you describe as to do so would mean they would have to construct it fully on their side of the boundary. Then the OP will have to construct a new wall on his side in the future. The only way to do the part wall is a sold block down the centre line constructed up to form a parapet. In my opinion of course. The. With or can then detail their side with whatever build up they want and the OP can detail their side in the future in what they want without affecting the structural element of the wall. I think Bryan's section sounds good if the space is there but I would use a 215 solid on the flat instead of the 150mm block.

I've not followed the discussion and really am only throwing in tuppence worth. I would have imagined a twin leaf possible with outer leaf spanning the party line (this is what I would have done in a recent, space tight, extension) so as to constitute the party wall.

(Bearing in mind I've not read much upthread) I'd advise the OP to at least post the proposed plan of the neighbours, whenever it solidifies, since actual intent likely to supercede any guess work on commentators part

Gumbo

antiskeptic wrote: »

My preparedness to bow to the advice of kceire should be noted by the OP





All fair enough if the neighbour is intent on a parapet-style construction.



I've not followed the discussion and really am only throwing in tuppence worth. I would have imagined a twin leaf possible with outer leaf spanning the party line (this is what I would have done in a recent, space tight, extension) so as to constitute the party wall.

(Bearing in mind I've not read much upthread) I'd advise the OP to at least post the proposed plan of the neighbours, whenever it solidifies, since actual intent likely to supercede any guess work on commentators part

Without getting into a childish argument with you, I wouldn't like to be the OP if you were building next door like that when it comes to the time of the OP's extension works.

redser7

Hi again. Haven't met with the builder yet. But another question came to mind.
This new party wall will be about 12 foot long I reckon. Just on the off chance we wanted to extend out further than that in the future, what does that mean? Would it be possible to extend the party wall another few feet by tying in a new section of wall somehow?
Just trying to cover all the bases here.
Thanks

sydthebeat

redser7 wrote: »

Hi again. Haven't met with the builder yet. But another question came to mind.
This new party wall will be about 12 foot long I reckon. Just on the off chance we wanted to extend out further than that in the future, what does that mean? Would it be possible to extend the party wall another few feet by tying in a new section of wall somehow?
Just trying to cover all the bases here.
Thanks

yes, no problem at all extending and tying in,in the future

redser7

Good to know. Thanks a lot Syd!