Previously, the only access to our attic space was a small hatch in one of the hallway closets. Our new upstairs will need a more reliable means of access; a functional stairway.
However, during construction this new stair is going to be subjected to the bumps and scratches common to building projects. So, we decided to make a temporary, "construction stair" out of standard dimensional lumber until the majority of the upstairs is complete. For the final stair I'm thinking about using a technique called a, "housed stringer", where I will mortise a space in the stair stringer for the risers and treads to sit, secured by wedges from the back.
This has the benefit of being much more stable than a normally constructed staircase, as well as saving the step of cutting a piece of finished trim to run around the treads and risers.
After creating a means of getting upstairs, the next step is to make the upstairs walkable and able to support the new floor load. To do this, we're going to sister on a joist capable of carrying the load onto the existing joists. This will connect the new and existing structures, strengthening both and giving us the maximum space to work with for running the new ductwork through the joist cavities.
With the framing in, the next step is to make sure that all of the utilities,(electric lines, plumbing, heating and cooling) that have to run through the floor are installed before we put down the subfloor.
construction stair
housed stringer