One place is hard-money lending.Still, my concerns remain for hard money: try to get a couple deals under your belt so you can more accurately forecast costs and time frames. 

Main thing is establishing who is responsible for the maintenance and repair which I would suggest is you as well as making sure that your insurance policy is accurately covered for a tenant with a pool 

Calling local contractors and asking for rough quotes will get you the most accurate numbers, and sites like Angie's List or HomeAdvisor can kind of give you a very rough estimate, but I'd stick with finding out numbers from local workers.

ConwellDo not rely on zillow for accurate/realistic estimates for a property.

At time the only benefit that a blanket loan might have is “lower” fees, but as a mortgage broker that deals with a lot of investment refinancing in Texas I don’t find that completely accurate.

@Tyler DixI’m a numbers guy and I want to believe there is always an accurate way to calculate rehab costs.

Anybody have any advice on getting accurate estimates for this?

Share profit & loss accurately based on the ownership split.  

I realize that I have to get more accurate number prior to making a deal, but I need to learn how to analyze a deal that will allow me to make an offer.How much do you think you can push the rents?

I would like to accurately estimate ALL of the costs here because we dont know what we dont know.