right, after a few days scribbling we have some ideas for you, but!
its very hard to know what we are dealing with here, Stander, that is not the bees.
so we have made some assumptions to it. one i expect that there is enough skill to make these things to within a few mm tolerance. i cant that why i have my set up my way.
also to fit these things in you are going to be looking at knocking a large hole out and will that not weaken your cabin to much?, i dont know so the answers are based on yes to most of them.
the basic gist is we build a box open sided that we can slide a brood box and supers into, now working on the idea that you will be using nationals rather than your own frames or we could also use lang or dadants the choice is up to you.
the easiest way will be to nail a timber batton to one side of the brood box another the wall of the new bee box and let them run on top of each other, we would normaly see a stop block on the outside edge of the runner to prevent push roughs and it makes it easy to push untill you stop.
i have done a few drawings below to give you some ideas,
now my lot are actualy sat on a framed floor set with standard nationals on top and through the floor a simple hole in the wall to let them outside, try the videos and see what you think.
personal rather than buying a cabin and then building the hives you will be better off buying a set of poly hives instead. i use a shed for historical purposes as everyone here well knows and i have found it very usefull for training exercises with newbees. all the rest of my hives are made from scabby ply wood and are outside near where i live with no protection at all from wind or rain, snow or sun