Also, I'd check A/C unit -central vs in wall - central will be more expensive to fix/replace vs in wall unit that can be swapped out easily as DYI.

Household furniture must be positioned and/or elevated to allow adequate air flow underneath and between furnishings and adjacent walls.

If you dig past surface level answers, you'll find plenty of truth...

My framer said that it shaved a day off on the walls alone.

Those quotes can be fair for a 4‑zone retrofit without ducts, but only if the scope is apples to apples: line-set lengths, BTUs per head, brand/warranty, electrical, condensate pumps, permits, and wall patching.

At the worst, we took out that section back to the wall and re-installed new planks.

Especially since you will not be present to make decisions quickly, sign off on change orders, assess the situation when the walls are opened up and the scope of work increases, etc. and that makes you more difficult to work with than someone who is local. 

What to look for in a good rent-by-the-room propertyThis matters a lot:• At least 3–4 legal bedrooms• Two or more bathrooms• A layout where bedrooms don’t share thin walls• Plenty of parking• A common area large enough for multiple people• A location near hospitals, colleges, or job centers• A basement or attic that can be finished legallyAnd most important:A floor plan where rooms feel private.Privacy is what keeps tenants staying longer.My honest adviceAt your age, with energy and time on your side, this strategy can fast-track you if you treat it like a business.But don’t do it blindly.Tour existing co-living houses in your area.Study your local ordinance.Model the extra expenses and the extra time.Room-by-room renting works, but it works because the operator is organized, not because the property magically prints money.

Remember, they will need hand supports so if you tile the walls make sure you save extra material to replace where you need to make holes for the supports.

In that little unit, I removed 5 walls and added 2 walls.