The garage and bsmt are "bonus" sq ft and enhance the property when comparing it to others to the point where it could make it more atractive...and sell/rent before the others.

I consider appreciation as a bonus for the whole endeavor. 

If you can upgrade the outhouse or set something up inside, bonus points for that. 

What do the builder warranty laws look like in your area and what is your potential exposure if you sell?

You will want to do installment payments where if the deadlines are met for getting let's say flooring, cabinets, and dry wall done by the 4th week, then they get paid with a little extra bonus. 

The walls tend to be very well insulated which makes for a bonus when renovating.

Bonus if you own it because it's not a Land Contract. 

You could look into a cost segregation study and factor in bonus depreciation, but it may not be worth it on one single family home.  

This cuts down on time and makes it simplier.5-You can also generate a bonus if they do an exceptional job or start them at 150 and promise to increase if the job is done well (you can pass along this fee to guests on Air B&B and others).Good luck!

You have a quarterly bonus that you get, even if it's different each time, through your company but there is certainty that you will get one = qualifying income3.