Our 1960's house had a pool added in the 70's. They raised the level of the backyard and poured concrete up against the exterior above the foundation level. The sill has rotted for about 2' will some deterioration for about 5'. I plan to replace the section but also raise the concrete foundation so it is above grade.

I will support the house with shores and remove the sill. What I then plan to do is to:
shorten the 2x6 studs,
cut the stucco about 2"above ground
drill the top of the current concrete
place rebar rod into the holes
tie in rebar horizontally
paint Weldbond onto the concrete
install a new PT 2x4 sill
form for the concrete pour
place concrete using the 2" sill gap
Install a small strip to complete sill

Does this make sense? I will now have a foundation that is above the ground level.

I used 2x4 rather than 2x6 to provide a slit to pour in the new concrete. Is there another option?

Do I need to put 6 mil plastic under the PT sill.

Why not cut the cement patio away about a foot, lower the soil and debri below the sill level and install a drain to devert any water that may collect in this trench and drain it away.

You need to get permits to change the configuratin of the foundation wall. Even to raise it. Something they failed to do when they installed the cement walk/patio for the pool. Otherwise the town would not have allowed them to cement directly onto the house wall. Big no no.

If you planning to raise the block or concrete foundation to above grade level, How are you going to deal with the floor that sits directly onto the existing foundation. Or do you have a short wall on top of the foundation before the floor starts?

Unless your experianced with this type of work, I suggest you get a professional mason in to do the work. It sounds easy but once you get started, you cannot stop. It will take several days by ones self to complete this type of project. Its hard, dirty and if any suprise appears, and they always do, how are you going to handle it? How do you plan to pour cement into a form if the top is sealed with the sill, and the sides are sealed with the forms built to support the cement?

You also said you have a stucco finish. Cutting this can be tricky and if not done correctly and finished proeprly you will end up with patches. As the stucco must end up lower then the sill area to protect it. How do you plan on getting the sill in place? This is a job better left to the professional.

Thanks for the response. Cutting a tranch on the outside is a possibility but I saw as creating a hazard for kids. As there is already a small wall on the inside (i.e. the slab is not poured on top), I would just be raising this 9".

My plan for getting the concrete in is to initially install a 2x4 plate aligned out the outside so that I have a slit along the wall to pour into.

While I agree this is not the simplest of jobs I have quite a lot of experience gained over many years.

I have cut this stucco before when installing doors and windows. I don't see this as a problem. A diamond blade eats it up!