Offsetting block work

[stuff4jas]

Is it possible to offsett blocks like I've drawn in the image?
I'm building an extension and the existing house has a delph stone plinth 1.2 m high with rendered blocks on top.
I've price up for reclaimed stone and can get it with a 125mm bed size but I've also found some more affordable good matches in reconstituted stone but can only get them in 100mm bed size.
I'd like it to match a near as possible but to do that I'd have to offset the blocks so the render does not form a lip where it meets the reconstituted stone which doesn't happen on the existing house.
Hope that makes sense

Untitled

• stuff4jas
• 10 Dec 2014
• 1

 

[tony1851]

No problem with that.

 

[RNReindeer]

Just one small point. I'm not a pro'.
When I was building an extension (in UK) the spec was for 25mm cavity insulation with a 25mm residual gap.
I used 30mm cavity insulation and the Building Inspector suggested (insisted?) that I offset the outer skin to maintain the 25mm residual cavity gap.
You didn't mention the cavity gap that you have to start with, but it might be desirable/required to maintain a 50/25mm residual gap.

I don't know whether it is permissable to reduce the existing cavity gap without some other adjustments/modifications.

 

[freddiemercurystwin]

The walls just need to be adjusted to suit the proposed insulation/air gap if applicable. Just slightly longer/shorter wall ties may be required to suit.

 

[stuff4jas]

If it was possible to do then I was thinking id make the cavity 15mm bigger until I offset the blocks and the cavity returned to the specd 100mm.
If I do offset the blocks will this be questioned by the BCO

 

[freddiemercurystwin]

No won't be an issue, are you proposing full filled insulation or partially fill (like Celotex)?

 

[stuff4jas]

I'm part filling with 50mm celotex/kingspan

 

[freddiemercurystwin]

Plough on!