Basicaly the same as mine but I went for 6ft long,5ft high with a peaked roof, for some xtra head room. My side window is a lot smaller,6inx 36in. I just need to be able to see my tip-ups. I like to keep it as dark as possible inside, as I can see down the hole a lot better. i would nail on 2 more 2x2's to the runners, making them 2x6,make for easier pulling. Cut 2 length's of plywood or chip board, 2 fit between the runners. When you park it where you are going to fish, put them between the runners blocked with snow or slush from your holes to keep them in place. I drill my holes first, then slide my shack over them. This keeps the slush + slop out of yourshack. Also keeps from ramming your knuckles onthe walls if your holes are in the corners. Having the boards between the runners keeps out the wind + light.