Beta-42 wrote:
I have a property that has an outdoor concrete stairway that leads to
a basement entrance. The steps run down below grade along the back
wall of the basement to a landing, and then by turning right one can
enter the basement through a door in the back wall. The landing is
about 18 inches above the basement floor level, so after entering the
basement door, there are 2 or 3 steps down to the basement floor.

What I would like to do is add a few more steps down along the back
basement wall, beginning at the end of the first landing (where the
existing door is), and then create a second landing that is about 18
inches lower than the first landing. Where the new landing will be,
I would like to add a second entrance to the basement.

The present concrete steps and landing are bordered by a concrete
block wall -- one along the side of the steps, and one at the end of
the existing landing at the bottom of the steps. The new design will
require knocking out the concrete block wall at the end of the
existing landing to continue the new run of steps down to the new
(second) entrance to the basement.
The existing landing has a floor drain that I think goes to a French
drain type of setup under the basement floor. It doesn't go to any
sewer line. What I think I would like to do is have the existing
floor drain and the new floor drain for the new landing go to a
similar French drain type of setup under the basement floor which
also can drain into a new sump pump pit that I will have installed.

If it's a straight-forward job, I may just go ahead and do it myself
with the help of a friend. Or, I could get some estimates from
concrete contractors and see what they say needs to be done. If the
concrete contractors know what they are doing and it doesn't cost too
much, I may just have them do it -- but I have a hunch that they will
want a lot more than I would want to pay when I could do it myself
for a lot less.
The part of all of this that I don't know about is how the new
landing and new added concrete block surrounding and retaining wall
should be built. In other words, is there a certain type or amount
of footing that needs to go under the new section of retaining wall? And,
is there anything special that needs to go under the new
landing, other than a stone base underneath? Is rebar required
anywhere?

You will need to ensure that the existing footings of the house, or change
the footings of the house so that they are below the frost line in your
area, you will find that this also applies horizontally so that when frost
enters the stairway wall it will freeze the ground in all directions, left,
right and down. For example if you have a 4 foot frost level you will need
the house and any permanent stair walls to have footings 4 feet below the
bottom landing and for 4 feet on each side of the stairway opening, as well
as below the angled portion of the decending stairs of they run beside the
house foundation wall.