Before having a contractor come out, I am trying to roughly estimate the cost of installing a brand new set of stairs from my living room down to our daylight basement. I'm trying to make it feel more like a two story house rather than the existing dank basement stairway. When I say new, I mean cutting an opening in the 2nd floor for the stairs. The house is a rambler in the Seattle area with a bearing wall running through the center. I'm proposing the stairs as a straight run parallel to and along the bearing wall. This means the 2nd floor joists that are currently sistered at the bearing wall will need to be cut and supported by hangers on a new beam (4 or 6x12) and posts to create the opening.
I'd likely finish the stairs with white oak flooring like the rest of the 2nd floor. I would do the project myself, although I don't think my family would tolerate my 6 month construction schedule considering other obligations. Here's is what I envision being involved in the project.
Sawcut holes in basement slab for two to three new footings (need waterstop around joint) - 1.5 days
Shore 2nd floor joists and cut hole in 2nd floor - 1 day
Install beam and hangers for cut joists on top of decorative posts integrated with stair railing - 1 day
Install stairway - 2 days
Finish 2nd floor opening, stairs and railing - 3 days
Any ideas on what something like this costs? I don't have much of an idea, but I am thinking it is 8 to 10 days with 1 or 2 guys. $10k? Any input is very much appreciated.