I've seen these a number of times on older homes. It always struck me as a very awkward way to get to the basement. Especially if it's used regularly.

won't it get real cold or hot in that area depending on the time of year? Have you considered a circular stairway?

If I understand correctly, you seek to expand your home so that you can place a stairway to the basement somewhere other than in the midst of the home.

I believe that could work. Placement will be important both for the loss of wall space on the main floor as well as entrance into the basement.

Consider a triangular bump-out. The stairway could follow the bump-out with a 90 degree turn at the landing, or reverse upon itself with a 180 degree turn. Windows at the main house level would capture light from 2 directions. The bump-out and stairway would add interesting archectural features to the home. This would be a small square footage addition dependant upon the width of your stairs and depth of the basement.

I'm still sifting through building codes to find out what the dimensions have to be for a basement stairway. I'm not worried about temperature extremes, since we're building in a moderate climate (SC), I'll insulate it well, and the temperature will probably match the basement, which won't vary much due to being under ground. The triangle idea sounds interesting- I'll have to sketch it to see if it works. The spiral idea would be cool, too- I could make a round tower for a stairwell! I don't see why it would be an more or less convenient than any other location. In this case, the door would be in between the kitchen and the dining area, so if you came upstairs for something- you'd come out in the kitchen- my favorite room of the house! I can get creative here, since I'll be designing it and building it. Thanks for the ideas- keep 'em coming!

I did a little more research. Code calls out a 36" wide stairway. A spiral stair is OK , too. A half-round bump-out with a spiral staircase- interesting! I'm not sure how much fun that would be carrying stuff, but the basement is a walk-out, so I can always get stuff in and out that way, just using the stairs for quick trips.

I'd keep the stairs inside. Bog stuff could be carried in from the walk out.

It is very good to consider all the options, then decide. Your idea is really not bad. A few houses in this area had basements added long after the house was built and used stairs such as you describe. A couple of churches were raised slightly on beams while a full basement was excavated with a tracked loader, a foundation built and the building placed on the new basement walls. In those cases, there was no place for an interior stairway in the existing building. In one case, one had to go outside to the new stairs. Never popular with the congregation. In the other, a new addition with basement was abutted to the existing building and that provided space for stairs and access. If it makes your floor plan work better, go for it.

Following up my comments from just a short ten years ago....

if you are doing this in a cold climate, the basement foundation wall under and beside the door should be extended another four-six feet down and insulated. And in any location, a drain should be added at the outside landing.