Need Advice : Installing pre-hung door in basement through foundation

I want to install a new insulated steel pre-hung door in the basement for energy efficiency and security. It will replace an old single panel door through the foundation opening beneath an exterior bulkhead.

The problem is, the stairs down from the bulkhead extend all the way to the interior edge of the foundation so I would have to alter/replace the stairs to install the new door inside the foundation opening. And I think the rise/run of the current stairs is already a bit steep. The top of the foundation is 72" high and the depth of the space for the stairs is 60 1/2" to the interior edge of the foundation (so installing a door inside the opening would make the rise/run ratio 72" / 56 1/2").

So I'm wondering if I should build onto the current casement that is flush against the interior foundation wall, or if I should take out the current stairs, install the door inside the opening and then rebuild the stairs.

I hope the pictures help explain what I'm talking about....

 

Personally, I would suggest you leave the stairs alone, but remove the flat door and frame yourself a wall on each side of the stairway... maybe 16-20" long... (creating a very short "hallway" for the door)... this would enable you to come down the stairs and get your feet on the floor before reaching for the doorknob.

If your door will be 36", I'd frame the walls 44" apart on the basement floor then create the door RO by adding two 2x4 onto each side... so you end up with a 38" opening in front.

If your door is a 32" just subtract 4 from the above measurements.

Add 1/2" sheathing to the walls to close them off and give you the right wall thickness for a prehung door jamb.

 

I like X's suggestion! It never fun to go down stairs and have to open the door while still on the steps. Don't forget to insulate the new walls, ceiling too if not already insulated.

 

Thank you for all your advice. I listened to X and left the stairs alone. But since it's a seldomly used (if ever) door and because a landing build out would block access to another part of the basement, I just built up the existing frame and hung the door in the same space.

I used Tapcon screws to screw more framing into the foundation. I tried using Dewalt powder actuated drivers and could not get them to fire for whatever reason.

Anyway, thanks again for all your help!