Due to being the same remodel as last year I've projected this remodel to be 6 weeks.  80% of materials are in my garage just waiting till we remove the cat piss odor from the basement. 

I have, however, had to rip out flooring in two houses because of cat urine odor that couldnt come out.  

To update this discussion- I ended up requesting a non-refundable hardwood cleaning fee for my floors (deep cleaning for pet odors) and allowed my tenants to get a puppy.

However, the odor can be glaringly present to non-smokers.

I said no, the minimum income requirement is $2,400/month.She grumbles walking out the door, "Didn't know you had to be rich to live in this place!"

So, it's your job to know what they will see - and that they will see that they're better off staying put, that what you've asked for is fair.They'll still grumble and hate it, but if they are happy with you otherwise and the unit, they'll usually stay. 

The refrigerator is more challenging because sometimes the odors are difficult to remove.  

People who smoke will track the odor indoors anyway and are also likely to smoke indoors when the weather turns bad.

I think odor is my biggest concern.

For cat odors, search for threads on cleaning cat urine/spray on here as you will need much more than standard cleaning -- we had to remove carpet, pad, trim, cleaned slab multiple times with vinegar, replaced sections of subfloor upstairs, Kilz on walls after cleaning with both vinegar and TSP.