New property, sloping addition: Fix it, fudge it, or leave it?

[Tucker Long]

Hey all! Just picked up a new property, it's two blocks away from on of the biggest universities in the world. Beautiful condition overall, despite being 120 years old. The whole house is super solid, with the exception of an addition built on the back.

The plan

Hold this house until I die. For now, live in the upstairs and rent or air bnb bottom out, can setup house as a functional duplex. 

The problem

I need to renovate the kitchen and add a full bath downstairs, current kitchen and this future bath are both in the addition. The entire addition is sloping uniformly away from the house at about 1 3/8" per 6' . The slope is uniform on both levels. It is substantial, you can feel it walking in, see it in doors and windows, and notice it when the back door drags.

The options

Luckily, a top notch foundation repair contractor offered to help me out. He's offered to walk me through the repair myself for a very modest consulting fee, he's doing it as a favor. Options...

1. Hire this well regarded contractor to level with his crew and special equipment, he described it as drilling columns 10's of feet deep around foundation, getting a plate under foundation attached to the columns, and raising it. He said rough ball park is $15k for this job.

Pros- done right, done fast, income starts sooner

Cons- Painful to spend the cash

2. He works as a consultant as I do the work with my own contractors/myself with this process: trench around the whole foundation, dig under footer ever couple feet, insert bottle jacks under footer between two steel plates, every two feet, life house several pumps at a time, going jack to jack, get it level, insert rebar and pump new concrete in for footer. Back fill. We've thought a lot through this, guessing I'd have around $5k into this + one to two weeks of my time...

Pros- It's done right for much cheaper, I have everything I need to make this happen including the time.

Cons- Probably will be summer before I get this and bath/kitchen renno completed. 

3. Leave structure in place, rip up kitchen subfloor (floor getting replaced anyway), add new level joists, relay floor. I'm not a huge fan of this.

Pros- Cheaper than previous option and end up with level floor.

Cons- I don't like doing things half way, this house is nice enough and ROI is good enough to do this the right way.

4. Leave floors as is, instead of doing full nice rehab just paint cabinets, drop in new sink and counter tops, and put in new floors. Install the bathroom on the sloping floors, will have to build up shower area to be level but no big deal.

Pros- Fast, cheap, income starts sooner

Cons- Obviously the annoying sloping floors, renovating kitchen and adding bath on sloping floors pains me.

Conclusion

I can put in the bath and kitchen leaving the floors as it quickly and at wholesale cost, I'm confident this is the route most people would take in my circumstance. However, I truly intent to keep this house for many decades/forever so a big part of my wants to go all out despite much higher costs and delayed income on the front end.

Please, share your thoughts, ideas, and experience in similar situations. Below are pics of the addition. Thank you!!!

Kitchen

Can see slope above door

Amount of slope

Upper addition, it's a sunroom/office/extension of small bedroom. Less concerned about slope here compared to first floor.