I am in the planning stages for converting my garage into an apartment and have a few questions. Some of the work I am having a contractor take care of.
The dimensions are 25' 10" X 23' 5" I will have the contractor raise the floor 4" to be on the same level as the rest of the house. To cover this span should I be looking for concrete piers with engineered joists?

Once the sub-floor is in I will be putting up the partition walls and I have 1 question. What do I do If 1 of the walls that runs the same direction as the floor framing falls in between 2 of the joists? Do I just add another joist to support the wall?

John Aerena

This project was put on the back burner for a while but now I am back in the planning stage.I still need help on how to raise the floor 4 feet off the existing garage floor.Attatched is the space that needs to be elevated.The entire shaded area.

Typically for walls parallel with joists - it is recommended to add a joist under the wall. Personally I would recommend placing blocking from joist to joist to carry the wall - unless it's a weight bearing wall. In your situation I don't believe you will have any interior weight bearing walls to consider.

And as far as raising it 4' - I would say your suggestion of the engineered joists with a pony wall would be your best bet.