I would want different accounts since he estimates he makes 7% interest on all of his rentals.

Here's a link to my estimated calculator report if you guys are interested: Portland Duplex Austin- I was able to shave off $4000 based on the inspection that suggested I needed a new roof within a few years.

I assume you're talking about estimated tax payments.  

You're right about the electrical estimate, I should definitely rewire the whole house while the studs are exposed.

The home that is on the market is priced at "market value" and sites like Zillow and Refin put their estimates at around our asking price. 

By my estimate, assuming your numbers were perfect, you’ll earn roughly half the profit you anticipate. 

@Jack Plantin I don't use percentages rather underwrite estimated/actual costs. 

In theory you could estimate it by looking at county info, knowing when they purchased and for what price then build out a amortization schedule. 

We will know in about a week how accurate my 85% estimate is. 

You will need to talk with a local builder to help determine feasibility and rough ball park estimate of construction costs.