[Help] Terraced House Extension Dimensions Help

Balders · Mar 17, 2021

Have got two quotes from a Builder with conflicting "advice" - hope somebody on here can help clear it up?

We have a terraced house and we want to extend out of the back - the internal width is 4.5m but I'm assuming that the dividing wall between the properties is circa 300mm (this is what we are being told would be the width of the brickwork on the extension)

One builder is saying that they can extend by the width of 5.1m to give us an internal width of the extension of 4.5m. However how does that stand presuming the side walls of the extension will be straddling the boundary line of the properties both sides (Party Wall Agreement and potential issues selling at a later date/neighbours reject it?)

The other Builder is saying that he'll extend from the line of the internal walls which gives us an internal width of 3.9m to keep things easier.

Obviously we want the most internal width without it being problematic - how far can we go to keep it simple? Hope that makes sense?

WATFORD zero · Mar 17, 2021

Firstly I should state that I know absolutely nothing about the legal situation here, but sticking your extension wall on your neighbour's property doesn't sound right (even if it's only partial).

LamieRobertson · Mar 17, 2021

Sounds more than a five minute job

GT49er · Mar 17, 2021

WATFORD zero said:
Firstly I should state that I know absolutely nothing about the legal situation here, but sticking your extension wall on your neighbour's property doesn't sound right (even if it's only partial).

It's quite normal with a party wall agreement.

WATFORD zero · Mar 17, 2021

GT49er said:
It's quite normal with a party wall agreement.

Didn't know that. I'd be a bit pissed off if I had a neighbour's extension wall built on my garden, (particularly as I'm guessing it could be quite wide on older properties) but I guess that's the 'agreement' part of it :thumbsup:

Billy the Fish · Mar 17, 2021

I've just had to do a party wall agreement, everything you need to know is on Gov.uk.

I think it's 1.5m from the boundary but it varies deepening on what you're doing but it sounds like you'll need one either way from those numbers.

Billy the Fish · Mar 17, 2021

WATFORD zero said:
Didn't know that. I'd be a bit pissed off if I had a neighbour's extension wall built on my garden, (particularly as I'm guessing it could be quite wide on older properties) but I guess that's the 'agreement' part of it

You have to serve them with a notice of works including plans. If they object you have to pay a few grand to a surveyor to come round and make you jump through even more hoops! It sounds like a horrible process if you end up in dispute.

Luckily I get on with my neighbours and they agreed to sign it :goal:

Balders · Mar 17, 2021

Billy the Fish said:
I've just had to do a party wall agreement, everything you need to know is on Gov.uk.

I think it's 1.5m from the boundary but it varies deepening on what you're doing but it sounds like you'll bed one either way from those numbers.

Deffo for the Builder that wants to go 5.1m - also doesn't help that our neighbour to the right, although perfectly amenable, from my calculations his garden fence is on the pi55 by 100mm onto our side (which isn't a problem for us currently) but they have a Conservatory and if we went 5.1m and asked for a Party Wall Agreement, our extension would be right up against his Conservatory..........ummmm

Billy the Fish · Mar 17, 2021

Balders said:
Deffo for the Builder that wants to go 5.1m - also doesn't help that our neighbour to the right, although perfectly amenable, from my calculations his garden fence is on the pi55 by 100mm onto our side (which isn't a problem for us currently) but they have a Conservatory and if we went 5.1m and asked for a Party Wall Agreement, our extension would be right up against his Conservatory..........ummmm

https://www.gov.uk/party-walls-building-works

Read this guide. There's a pdf booklet which is very good. It sounds like you'll be excavating within 3m of their footings so to the letter of the law I reckon you need it either way. The flipside is that it's only a problem if they complain before you've finished!

dejavuatbtn · Mar 17, 2021

It will be an interesting build if they can’t venture onto your neighbour’s land, or you want to maintain the outside in the future.
Personally. I wouldn’t have the cheek to go too close and expect to get access to its outside wall.

Balders · Mar 17, 2021

Billy the Fish said:
https://www.gov.uk/party-walls-building-works

Read this guide. There's a pdf booklet which is very good. It sounds like you'll be excavating within 3m of their footings so to the letter of the law I reckon you need it either way. The flipside is that it's only a problem if they complain before you've finished!

Builder who is saying 4.5m so starting from our internal wall is saying we don't need a Party Wall Agreement - tbh both neighbours won't have any problem with this whatsoever - the fun will be if we want to eek out up to an extra 500mm and we start getting very close to his Conservatory.....

GT49er · Mar 17, 2021

Balders said:
Builder who is saying 4.5m so starting from our internal wall is saying we don't need a Party Wall Agreement - tbh both neighbours won't have any problem with this whatsoever - the fun will be if we want to eek out up to an extra 500mm and we start getting very close to his Conservatory.....

It's potentially an advantage to your neighbours to have a party wall agreement, because the wall built on their side of the border becomes their wall, and they can use it as part of their extension if ever they decide to get one - one wall built already. Or they can attach a conservatory to it. If the wall is your side of the boundary (i.e. not a party wall), in theory at least they can't even knock a nail into it for a hanging basket.

Balders · Mar 17, 2021

GT49er said:
It's potentially an advantage to your neighbours to have a party wall agreement, because the wall built on their side of the border becomes their wall, and they can use it as part of their extension if ever they decide to get one - one wall built already. Or they can attach a conservatory to it. If the wall is your side of the boundary (i.e. not a party wall), in theory at least they can't even knock a nail into it for a hanging basket.

Just got the tape measure out - if we went the full 5.1m then our wall would run 2/3rds the length of their Conservatory and there would be a gap of circa 200mm between our brickwork and their lovely glass Conservatory on our side for which we would need their agreement, as opposed to circa 550mm which would leave room for him to keep his fence and a bit more of a gap!

Shropshire Seagull · Mar 17, 2021

Maybe buy a bigger house?

If this causes neighbour discontent you might end up feeling you want to move anyway ....

HAILSHAM SEAGULL · Mar 17, 2021

No part of your extension/conservatory should cross the boundary line. This even includes gutter overhang.
A party wall agreement will keep it legal, its alright your neighbour saying they dont mind, but what happens if they sell up, the new neigbours would have a case
without a PWA.

Balders · Mar 17, 2021

Shropshire Seagull said:
Maybe buy a bigger house?

If this causes neighbour discontent you might end up feeling you want to move anyway ....

Been through that process! Like I said originally reducing the width to avoid a Party Wall Agreement isn't ideal but acceptable, but when we look at what we can buy adding the cost of the extension, with the extra space here, we'd rather stay put. We basically have a 2up, 2 down, but we have a small kitchen and dining room and extending out and taking out the internal wall gives us exactly what we want which we couldn't find elsewhere. It's just stupid things (the devil is always in the detail!) where we will be housing the Fridge/Freezer/Tumble Dryer in the extended part - with the 5.1m extension that would "flow" with the new kitchen, but losing 300mm each side means those items will "jut out" 300mm. First World Problems and all that, but the other half wants it perfect!!

GT49er · Mar 17, 2021

Balders said:
Just got the tape measure out - if we went the full 5.1m then our wall would run 2/3rds the length of their Conservatory and there would be a gap of circa 200mm between our brickwork and their lovely glass Conservatory on our side for which we would need their agreement, as opposed to circa 550mm which would leave room for him to keep his fence and a bit more of a gap!

Party wall on one side then, and lose a bit of width to stay clear of your neighbour's conservatory on the other.

Balders · Mar 17, 2021

HAILSHAM SEAGULL said:
No part of your extension/conservatory should cross the boundary line. This even includes gutter overhang.
A party wall agreement will keep it legal, its alright your neighbour saying they dont mind, but what happens if they sell up, the new neigbours would have a case
without a PWA.

That's exactly where I'm now coming from "accepting" a reduced floor space for all the reasons above!

Balders · Mar 17, 2021

GT49er said:
Party wall on one side then, and lose a bit of width to stay clear of your neighbour's conservatory on the other.

Is an option

However the losing a bit of width is the side where the new kitchen is going in - see reply above :ohmy:

Norman Potting · Mar 17, 2021

..I was sure that this was going to be an HWT obscure bands thread

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