Side return/rear extension using existing garden wall

[samtaylor]

Hi i have a garden flat in a victorian terrace and am about to undertake a single story side/rear extension. A builder told me we can build using the existing brick garden wall.
i have a couple of queries:
1. I presume he doesn't mean just insulate the garden wall. is this even possible? I'm guessing a cavity and block-work is required no?
2. The existing garden wall obviously doesn't have a DPM. How will this work without one?

I have added a few pictures and a drawing for clarity,
any advice greatly appreciated.
Cheers Sam
I

 

[JP_]

Sounds a bit dodgy to me for the reasons you mention, plus foundation depth will probably not please building control.
Get a 2nd, 3rd, 4th opinion..... ask them how they'd build around the wall. I should think most will probably say they need to remove it first.
But I am no builder so cannot say for sure!

 

[samtaylor]

Hi Jonbey, i would tend to agree but the structural engineer seem to think its fine. Sam

 

[samtaylor]

thinking of doing this?

 

[JP_]

Well, if the structural engineer says it is ok, then it must be! Although, surely you will have a cavity and inner wall too?
Did the structural engineer dig down by the wall to see how deep the foundation is?

 

[samtaylor]

yes we did about 600mm (with 100mm from the face of the wall to the edge of the corbel)

 

[HERTS P&D]

Get a new builder, this one is cutting corners before he has even started.

Andy

 

[samtaylor]

i don't think so Andy , the neighbours on both sides don't want the wall touching so I'm kind so I'm kinda stuck for options

 

[HERTS P&D]

Ok, crack on and good luck.

Andy