That's much clearer now thanks Tony. It was the typing error that threw me with the perp joints.

Yes there will be a concrete floor on the inside.

There is a concrete floor in part of the building but it's very uneven as it was used for housing cows, ie. sloping floor, feeding troughs and drainage channels. Other areas of floor are made of red brick. All floors will have to be taken up and a new one installed.

With regard to thermal mass would it be wise to use something like thermalite blocks in the 'cold' parts of the building (north and east sides) where there would not be any solar gain?

Okay that seems sorted. Now for the openings....How would you recommend finishing around door and window openings? Reading Brenda & Robert Vale's Autonomous House they used wbp ply formers which stayed in place to reduce thermal bridging. Is this the way to go?