What is the correct way of joining a new loft room onto an old loft room (nextdoor)?

[Soffit]

Just that really - what did/would you do and what were the cost implications?

Are you saying you want to build a loft extension and next door already has one or are you saying you want to put a door from one new loft extension into an existing loft space... More explanation required!

Yes, I want to build a loft extension and next door already has one/ Sorry if I was unclear

I wouldn't have thought you would join them, even if the houses are semi/ terraces.
All the ones here are very definitely separated

Do you mean using the wall of their loft conversion as a supporting wall of your loft conversion? That's done a lot on terraces so I assume builders are quite used to it.

@EvilRingahBitch

Do you mean using the wall of their loft conversion as a supporting wall of your loft conversion? That's done a lot on terraces so I assume builders are quite used to it.

Yes, I was wondering how this works in practice? If they were not joined then wouldn't this create a dark tunnel space?

@Glittertwins

I wouldn't have thought you would join them, even if the houses are semi/ terraces. All the ones here are very definitely separated

As above, for a deep conversion, wouldn't this create a long, narrow gap?

Is there a 'correct' way of doing it for bog standard Victorian terraces and couldn't it mean that one house will end up with a different size conversion to the other if the older one is not exactly half the way across?

Well I certainly would not want anyone joining onto ours as it is tiled

I think you have to talk to them and it becomes a party wall??? Probably easier to have a gap

So are they mostly joined together in high density areas? What would the advantages be for the person who built first? (warmer maybe?)

@5zeds

I think you have to talk to them and it becomes a party wall??? Probably easier to have a gap

Would the one who built first have a right to refuse or is it automatically granted is what I am wondering?

You organise an architect to draw up plans who will tell you how it is done

Don't think you can DIY this one ... 😂 or your NDN will have 'words'

Yes you'll definitely need a party wall agreement and a survey

I think you can object to anyone attaching themselves to your existing property but someone could build up to their boundary.

I think you either have a party wall agreement or build a new wall right up against their wall with no gap inbetween. Assuming they’ve built right up to the boundary.

Thanks. They haven't built right up to the boundary. I mentioned it to them and they are interested in doing it as it may be beneficial for their loft which is often cold. The part up to the boundary would be theirs. I would not be setting up house on that part!

Oh. I see.

You get a party wall agreement set up, should be easy as they want to discuss insulation. And in that agreement you and your neighbour agree what goes in the space between your walls. It only needs be a brick width and you can agree to stuff it with all sorts of sound dampening materials.

It should be part and parcel of the design and planning of your extension. All very common, usual procedures apply.

Thanks. Would any payment typically be involved?

That depends entirely on what you decide. If you are on friendly terms you could just split the costs of whatever additional insulation you decide on.

Thanks, something to think about for sure. I see so many loft conversions in my area and I wondered whether there is 'an established way'. Since most terraced houses have them then there should be really.

There is, for the minimum standards. That's were your design will start. But that doesn't mean you and your neighbour can't agree to something different.

If your neighbour has built right up to the boundary then you can build up to their wall. If your neighbour has built short of the boundary you are unlikely to be able to do this and you will need to ensure there is enough gap for drainage etc. In all circumstances there will need to be a party wall agreement. Your first step is to get an architect to draw up plans and let you know what is possible. I would also mention it to your neighbour because if they have their plans it could be helpful to see how they did things structurally.

Would it make any difference to future saleability?

@Hothammock

If your neighbour has built right up to the boundary then you can build up to their wall. If your neighbour has built short of the boundary you are unlikely to be able to do this and you will need to ensure there is enough gap for drainage etc. In all circumstances there will need to be a party wall agreement. Your first step is to get an architect to draw up plans and let you know what is possible. I would also mention it to your neighbour because if they have their plans it could be helpful to see how they did things structurally.

Thanks - do you mean the literal midpoint or the edge of the boundary wall? They have built up to the edge of the wall so I would be covering the whole wall with my conversion

@Soffit You really neeed to stop asking questions we can't answer absolutely. The only honest answer to almost everything you have asked is: Regulations, Party Wall Agreement and it depends.

Hire a professional and ask them for answers based on the reality, the specificity of your house.