Integrating brickwork to Sips panels ?

[Post and beam]

We have a large fireplace opening in the Sips panels of our house shell. There will be a large inglenook and working chimney.

The TF company have washed their hands of providing any advice and simply say ' thats not within our scope, it is for your bricklayer'

 

This is not within my skilset and i am at a loss to know how the hearth is to be integrated into the living room at 90 degrees to the Sips wall such that we maintain airtightness. No detail is provided within the construction drawings and my chosen brickie appears to be perplexed by the thing. I assumed this would be second nature to an experienced Brickie.

 

Can anyone offer any real world experience of the subject please?

Edited November 29 by Post and beam
Pictures added

[Russell griffiths]

I’m presuming that brickwork around the fire place is cavity construction with a fairly substantial cavity with insulation installed. 

the drawing isn’t clear. 
I would not expect your bricky to have ever seen this, sips construction is far from a regular thing to come across, and fitting a fire place like that adds to the complexity, I would sort the details thoroughly yourself, as you know your average bricky will not appreciate what cold bridging is or air tightness. 
 

you need to continue the insulation layer that the sips provides around the fire place

so you need a continuous insulation layer from right to left.