terraced house rear extension - boundaries and foundations

[^woody^]

Well you do live in the past woody.

It's a better place

 

[biryani_boy]

Presuming the party wall 1 brick thick a cavity wall is going to protrude into the room. Either design the different wall depth into the kitchen, maybe fit a deep worktop and cut to 600 where required, or batten the wall off.

The party wall is far from one row of bricks. It’s much thicker than a cavity wall, you can barely hear a party through it. 1950’s council house, solid as a rock!

Either way, I was more interested in the planning/legal side of things. I saw many extensions built as extensions of existing walls, I thought there might be a way to do it.

Party wall I’m familiar with, the technicalities of an eccentric foundation are ok, relationship with neighbours is so far very good and council is happy to give all required permissions as long as I meet building regulations.

Any views on how much a roof will overhang on the side and is there a trick to make the roof flush with the wall?

There must be a solution, it’s 2022 (nearly).

Thanks for all the info so far

 

[biryani_boy]

Would a flat roof solve the problem???

 

[Harry Bloomfield]

Any views on how much a roof will overhang on the side and is there a trick to make the roof flush with the wall?

Well, almost flush....

If the extension's roof slopes and drains only on the side opposite the house, then gutter is only needed along that back roof edge. If the tile edges down the side facing the neighbour are simply flounced and the wall simply replaces part of the fence. The foundations might be an issue as they would be partially extending into your neighbours side.

 

[SpecialK]

PMSL are you living in 1987?

"PMSL" do you have anything constructive to add?

 

[^woody^]

A flush side needs a parapet or inset gutter. Both compromises, higher risk and last resort where no other options are available.

 

[noseall]

Any views on how much a roof will overhang on the side and is there a trick to make the roof flush with the wall?

Depends on design/orientation i.e. gable wall, hip roof etc. An average soffit over hang (200mm) plus gutter (125mmish) amounts to over 300mm. A cut brick gable could impart as little as say 40mm overhang.

As said a flush finish is risky and the last thing I'd consider, even losing a bit of space is far better than a potentially troublesome design.

 

[noseall]

A flush side needs a parapet

And a coping presumably?

 

[^woody^]

And a coping presumably?

Or a capping

 

[noseall]

At least parapet walls keep us busy on this forum.

 

[biryani_boy]

one more question people...

happy new year, by the way!

remember how I said the neighbour's house is offset to the front? the gutter serving the corner bit of MY roof is "overhanging" the neighbour's boundary, just like the gutter serving HER part of the roof at the front of the house is above my boundary. say I got "permission" from the neighbour to build, could the existing gutter, put there by the original builder (council), be used as a precedent? I'm technically "breaking the rules" as we speak, and so is the neighbour, but that's how these houses were originally built.

also, am I right in thinking I don't need gutters at the sides of the roof? all extension I see have the gutter at the front, above the extension patio doors.

thank you!

 

[Harry Bloomfield]

remember how I said the neighbour's house is offset to the front? the gutter serving the corner bit of MY roof is "overhanging" the neighbour's boundary, just like the gutter serving HER part of the roof at the front of the house is above my boundary. say I got "permission" from the neighbour to build, could the existing gutter, put there by the original builder (council), be used as a precedent? I'm technically "breaking the rules" as we speak, and so is the neighbour, but that's how these houses were originally built.

I think the point there, is that the original builder/council built them like that, so no permission needed from themselves. You bought with the situation what it was, so cannot complain about the overhang, but for any new overhang - you need the other parties permission.

 

[biryani_boy]

got it.

based on this, I will probably end up going with the following:

1. pitched roof (towards the read garden), to avoid needing gutters on the side. I will only need to find out how much space is needed to "seal" the tiles on the side, I'm reading anything between 10mm and 150mm, there's quite a difference there.

2. I will not build exactly to the wall, instead relying (if needed) on internal plaster to make the walls flush. I might lose a few cms inside, but at least everything will be on my side, no legal problems further down the line.

3. as the foundations are allowed to "extend" under the neighbour's property if I serve the correct party wall notice, I will simply use the extension walls as center points for the foundation, might have to go about 15cm under neighbour's land, but I think that might be fine. worst case scenarion, eccentric foundation it is.

thanks for all the advice!

 

[^woody^]

based on this, I will probably end up going with the following:

What you should be doing is determining what you actually want and then designing how to achieve it.

What you are doing seems to primarily concentrating on constraints that don't actually exist and building in needless limitations and unnecessary compromises.

Ok, the relative may well be able to work out technicalities for free, but you will be paying a cost for that, not saving.

 

[biryani_boy]

I disagree.

my main objective is to maximise my space for family/entertainment purposes. how I do this, depends a lot on how much I'm allowed to build (not that I'm likely to use all the space I could legally use). if I can extend my extension 3.4m, which is the current "plan" (vision, desire, thought), then I'll do that. if I can extend 6m, I'll still extend 3.4m. if I can only extend 2m, I'll extend 2m and reasses my priorities. for example, I would really love a utility room, but not to the detriment of my entertainment space. if I can fit it in, fine, if not, fine.

all I want to understand is what options I have with regards to maintaining the "flow" of the property by not having staircased walls, weird L shape layout and other unnecessary complications. I don't think I'm doing things the other way round, I just need to know what I can realistically build in my circumstances without causing problems now and in the future (sell, remortgage etc.). once I know how much space I have, I'll be able to work out exactly what needs to happen.