We have a blank canvas living room at the moment. Looking at gettingthis insert wood heater positioned in a floor to ceiling enclosed island(?) in living room (hallway on one side, living room lounge area on other, walkway to hallway/lounge either side) but I'm wanting to have a linen cupboard (45mm deep) on the hallway side of this island.

I'm struggling to work out if it is possible to have a linen cupboard or would the 'island' be too deep? I think the island would look too monolithic from the side view if it is depth of fireplace plus depth of linen cupboard, so I thought maybe fireplace on bottom and then linen cupboard shelves could start higher where flue is, where there's more clearance space??? I find the manual for wood heater confusing to know how big my 'island' structure needs to be and what would be the minimum depth I could do it to have the linen cupbord at back of the wood heater. Appreciate some help!