Triple glazing would be good - you will have glorious sunshine first thing in the morning - but I may get a little chilly later in the day as the sun moves around ! - we have found some vines that thrive well on a north face (unusually ) I will ask my green fingered friend when she comes over next, what it's called as it looks glorious !! So maybe layering tactile throws Sheep skins / cowhides and rugs would add warmth - and creams, warm greys and mabey embrace the industrial look ?! Its very in right now - think it would fit in beautifully - especially if you keep some areas of brick exposed ?!? Will also allow lighting cables to be exposed this way ?! Or for a more sophisticated look use lighting on guide wires instead ?! Insulation will need to be extra thick - the regs have more than doubled in the last few years - underfloor heating would make the room feel toasty ?! And for extra splashes of warm lighting throughout the day - as there's room inside this space height wise - why not have a couple of olive trees with warm white fairy lights - if they are positioned near the window area they will thrive well ( have them on 'skateboards' type wheeled stands so you can turn them to even the growth) think you could easily have three along the yellow highlighted wall - one each end and one at the central wall area ! Looks a fab project ! I bet the views are awesome too !! Lucky you !!!