I've finally made a start on my interior, I have somewhere to sleep!

Next I'm making a start on the side units, someone has already cut some big holes in the side of the van for a 3 way fridge so the fridge position has been decided for me and I need to build the rest of it around this.
I have recently read that the back of the fridge needs to be sealed from the living area but I'm unsure how to achieve this while still leaving the fridge easy to remove for servicing etc.
My loose plan was to make a platform for the fridge to sit on (hopefully with space for a propex umderneath) then a sheet of ply either side of the fridge profiled and stuck to the side of the van. I would then insulate and ply line the rest of the wall around this box, build the rest of the cupboards around it and finish it with a removable worktop to allow for servicing.
Do I need to actually seal around the fridge or if I box it in nice and snug is that enough?