SIPs for partition wall or stick to stud wall

[Hamish]

I am in the planning phase for a 6m x 4m detached single story SIP garden room. For which I have contracted with Modular SIPs to provide the SIP kit. The floor layout will involve an internal partition to yield a ~1.5m x 4m garden store and the rest being a workshop. I recently posted separately re some issues I am having getting to certainty on my plan for foundations. However I am also not sure how to best achieve the partition. 

 

The options I have are:

 

1. Use SIPs plus firing to make partition (98mm panels)
2. Construct a stud wall

 

Here again is my current foundation plan (which I am told has cold bridge problems at the sole plate...)

 

 

Now if I use SIPs for the partition I assume the panels will need to be fitted onto a sole plate which is itself attached to the concrete raft. This will mean that the insulation would need to be installed either side of the partition and would be very much permanent wall. There will I think also be the issue around vertical fitment given that the raft may well have imperfections. 

 

With the stud wall I assume I could put the sole plate on the screed and just erect the partition from there.

 

I originally thought the SIP partition would be nice and quick as well as be pretty easy. However I am now basically thinking it is a bad idea.

 

Welcome thoughts on this.