Questions for the wise

[bobbidill]

Hi Folks,

We're in a bit of a pickle and I would really appreciate the opinion of those more knowledgeable on party wall matters than myself!
We're planning to build a rear dormer loft extension to our mid-terraced house.
Our neighbour on 1 side already has a loft extension, which is shown in the attached photo.
The cheek of their extension is built to the middle (or thereabouts) of the parapet party wall as shown in the photo.
We would like to build the cheek of our loft extension to the middle of this parapet party wall and we had originally planned to build up the parapet party wall in brick, to separate our 2 extensions and to act as the cheek wall.
We had thought that this would be possible as our neighbour had told us that their extension was set back from the parapet party wall. I've only just found out today that this isn't the case, after visiting my other neighbour and looking up at our roof from there, as you can't see this detail from our garden. Of course I should have checked beforehand rather than just taking my neighbour’s word for it, but we are where we are now.
We will issue Party Wall notices of course, however I haven't been found anything which answers the following questions, so I don't know what work we're allowed to do, which I will then describe in the notices.
So my questions are (a) will it still be possible for us to build our loft extension to the middle of the parapet party wall and if so, how would we do this? (b) can we join our loft extension onto our neighbour's, even if they do not want us to do this? We’ll of course talk to them and see what we can do, but I’d like to know our options as he's a landlord and doesn't live there. (c) Do you think we'll still be able to extend the parapet party wall upwards in brick as we'd planned?

Apologies for the lengthy post and thanks for helping.

 

[Nakajo]

To my mind, raising the party wall creates a better detail; it really should be mandatory on full width dormers. Anyway, you can prepare an award that allows you to do this, regardless of your neighbour's objections. I suggest you speak to a party wall surveyor.

 

[bobbidill]

Thanks Nakajo. Any idea if we would be allowed to strip back the part of our neighbour's extension which is on the parapet party wall in order to allow us to do this?

 

[Nakajo]

Yep, that's what I anticipate that the award would allow.

 

[bobbidill]

Great, thanks! Hopefully we can agree this with our neighbour ourselves!

 

[geraldthehamster]

I don't see how a Party Wall notice can permit you to remove part of a neighbour's structure

 

[wessex101]

I don't see how a Party Wall notice can permit you to remove part of a neighbour's structure

Because the Party Wall Act gives the building owner that right. The adjoining owner was very poorly advised when they just raised one half of the party wall, they should have raised the entire thickness or left it alone.

I suspect it will be a very tricky detail to sort out now as I would expect the existing party wall to be 9 inches thick solid brickwork and I bet the cheek of the new dormer is only studwork with tile hanging. With a new dormer abutting it the raised party wall separting the 2 dormers will have to comply with fire and sound insulation which will be very difficult to achieve if half of it is studwork and not built to the required standard.

 

[liam86]

Have a look at section 2(2) of the Act: https://www.legislation.gov.uk/ukpga/1996/40/section/2
This allows the OP to strip back the tiles as required; leaving any back-board in place would probably be best.
I imagine you would then form a suitable timber structure which allows for the right depth of insulation and boarding to meet insulation requirements. You would normally add insulation to the gable ends of a solid brickwork wall in the loft anyway so match this depth. Not ideal as continuing the brickwork would be preferred as mentioned above.
Main concern would be flashing, so would probably make the height of the dormer match the ridge height so is suitable higher than the neighbours finishes.
This method would not fall under Permitted Development but I guess the OP is already aware of that.
A Party Wall Surveyor is definately required. I would try and ascertain the build-up of the neighbours wall and make any adjustments to make their side safe part of the agreement - though I am not sure how far you can/should go with this.
Did they have planning permission by the way?

 

[geraldthehamster]

Have a look at section 2(2) of the Act: https://www.legislation.gov.uk/ukpga/1996/40/section/2
This allows the OP to strip back the tiles as required; leaving any back-board in place would probably be best.

Which provision of that section do you think allows this?

 

[liam86]

Hi geraldthehamster,
I was referred to 2(2)h, recently by a Party Wall Surveyor, for what I thought was a similar situation: We needed to remove a render finish to a neighbours ground floor wall which sat adjacent to the party wall, which we were extending... if that makes sense. So the render would have been i the way of the extended party wall. I would think the case above is more clear-cut as it acts as the party wall itself. My understanding is that the OP could remove the entire structure which overhangs the party wall and rebuild but this would be more comlicated and expensive.

 

[geraldthehamster]

From the account, there is nothing overhanging the party wall, nor is a wall being built next to the party wall. One half of the party wall itself has been raised, and tiled. So I'm not sure which case in that section could apply.

 

[wessex101]

How can you say it does not overhang the party wall...it is sitting right on top of it!

 

[^woody^]

The PWA will give you rights to remove their cheek, raise the wall and seal everything back up again.

But more practical, would be to just leave the dormer cheek untouched, construct half the wall and then felt over the join with the roof cover. This will be a new single party wall, and the Act will apply and allow it.

It will need to be suitably designed though.

 

[geraldthehamster]

How can you say it does not overhang the party wall...it is sitting right on top of it!

As I understand it the neighbour has simply raised one half of the party wall.

 

[wessex101]

As I understand it the neighbour has simply raised one half of the party wall.

Either it is the neighbour's wall as you said in #6 or it is a party wall. It can't be both. Either way the OP has the right (technically) to remove it and rebuild/raise the party wall properly.

As everyone has suggested it probably wont come to that and it will be a bodge job of trying to build alongside the existing dormer but I certainly don't know how you would get that to comply with fire separation and sound insulation from both sides of the wall. I suspect taking down the dormer cheek and raising the wall in 9" brickwork could well be easier and cheaper.

One thing I am sure about is a party wall surveyor or two are likely to make a pretty penny trying to sort this out.