Following on from my questions elsewhere on oak cladding..  I'm trying to understand how these windows were/are done. In particular the sawn oak outer frame and head. Is that fitted before or after the window? eg Do you line the window opening with 1.5" thick planks and fit the window inside that or fit 1.5" x 2" square strips after the window is in?  Thanks.

Suplimentary question:

Went to my nearest saw mill today to get a quote for the cladding. They asked if I wanted it put through the thicknesser? Do I? How rough is wood straight off the saw?  In the end he quoted to run the cladding through once "to take the lumps and bumps off".  

Price for 1150 ft of 1" x 7" was £1064+ vat

That's cheaper than I've found online but is it worth paying more to get it run through twice or ?

Can you tell I've not done this before  

It depends how rustic you want it to look.

Sawn oak can have a lot of black marks from the bandsaw blade which will make it look more agricultural than rustic, but they fade after a while.

It may look a bit odd if it has patches of planed timber alongside sawn.

I see Wolf has sugested getting a sample; thats a good idea