Lee that looks like a REALLY nice start to your shop/upstairs all open or gettign sectioned off for living storage work shop??
Make sure to get additional skirt boards under them to keep critters from getting under the slab when ya eventually get some concrete in there. It took 8 or 9 years for me to get the concrete in mine and I ended up re-doing the stairs going up into my 2nd floor. It was a straight staircase that went into the middle (spot like yours but stairs went straight up along back wall. I took them out and put in a set like yours in the corner tho.
Mark