You can't make alterations to the bathroom, send the builder invoices and tell him his grout work was bad.

It's three units above a first floor office space, which already has a full bathroom.

Avoid lipstick on the pig.Renovations like nice kitchens and bathrooms are great for rental properties, but it is not everything.A property that has been cosmetically renovated, but has no capital improvements is worse than one that has been very well-maintained, but might have older cosmetics.If I walk into a property and I see that the kitchens and bathrooms have been redone, but all the walls are plaster there's no grounding in the electrical and the plumbing has never been updated that I consider it a full gut.It's a shame to pay a premium because of a nice kitchen and bathroom only to find out that you have to rip it all apart.It is usually less expensive to do cosmetic rehab for rentals than capital improvements. 

Try looking into zillow/Redfin and see what your potential rents you can get near the neighborhood by filtering the bedrooms/bathrooms of the intentional property that you are planning to buy.

The only place we are having issues is one of the bathrooms where we are not able to get rid of the smell.

Nice kitchens and bathrooms are great, but if all the mechanicals are old, electrical is outdated, and its all made up of plaster walls, you might as well gut it. 

The house is under some distress: the bathroom in the basement is in very poor condition and plumbing does not work.

Horses will also designate a bathroom area and that area will be a urine and poop landfill.

I am an out-of-state investor interested in purchasing a duplex (2 bedrooms, 2 bathrooms each unit) located just a 10-minute walk from ASU.

We will be doing a fix and flip and 3/1 or 3/2 (if we add a 2nd bathroom) would be a big difference for selling purposes.