Here is some pics of my 48x48, its a butler farmstead builder. It was here when we moved to the farm.
The one pictures is it all cleaned out, ready to add gravel. We had to add about 80yds of c base to bring the floor up so water wouldnt run through it in the spring. The 2nd picture is it starting to fill up with equipment after the gravel was added. I included a 3rd pictures of the outside.
I've since added a man door to the north end (same side as the fuel takes in the pic). Its nothing special, but works great to keep the snow off the equipment. I have a wood stove in there but ussually dont do too much work in the winter, as I have a heated attached garage (26x26x12) and a wood stove in a insulated workshop (20x30x14). If you want anymore pictures ill see if I can find some.