Extension using existing outside wall

[robbie77]

Hi,
I am planning an extension to my house that will result in the knocking down of old outside buildings in the courtyard (old o/s toilet and coal store). I did some sketches and now currently have someone finishing the plans (hopefully).
The original plan was to knock everything down and start again but I am wondering if it is possible to use the existing bricks on one side and tie into them with blocks? I could use the brick that would match from the outbuilding so it would match and it would save a fair amount of work.
The wall is tied into the house and the existing utility room but I am unsure what can be done.
If I dig down and expose and bulk out the foundations is this possible.

Hopefully you can see both sides of the wall and the utility room that has a lean to roof.

 

[^woody^]

You can re-use the bricks, but will likely need new foundations.

 

[robbie77]

You can re-use the bricks, but will likely need new foundations.

So that means basically knocking down everything and excavating the foundations and building back up? I was wanting to keep the profile as in picture 1 and then build on top of that.

 

[^woody^]

You can potentially convert using existing walls and foundations, but if you knock walls down or try and add an extra skin to walls then that is a new building and will need new foundations if the existing ones are not up to todays standard - which old ones wont be.

 

[robbie77]

I am in two minds though as the original bricks have lime render and some pointing that was done in the pas was sand/cement that has blown the bricks so I would probably need to use lime on that side and find someone who knows how to work with it...
I think I am right in thinking that a 73mm brick would tie in with imperial with some jiggery pokery probably cheaper and easier for me to get a bricky to work with imperial /sand cement format?

 

[^woody^]

You can tie an imperial brickwork gauge into an internal metric blockwork gauge no problem.

You probably don't want to be rebuilding in lime as this will not be compatible with modern construction. But if you are somehow adding to the existing walls then yes you can use lime and then build the rest of it to reflect the flexible and breathable nature of lime walls.

You need to think carefully about what you want and how best to achieve it, and not be constrained by trying to make do with what's there already, as that may not be the best or cheapest option.

 

[robbie77]

Yeah. It's a no brainer really if its a new building and it needs a new foundation, I will demolish the lot and rebuild with sand cement and brick (callerton weathered red) that i thought was a good match on my garage. https://www.jewson.co.uk/building-m...RIBK951/ibstock-callerton-weathered-red-73mm/
The only real pain is the utility holds the boiler (oil) and pipes etc that I will have to relocate otherwise life can go on as normal.
Thanks at least I have ruled that out...