Let me know if I am missing anything.Purchase cost of an old house on a 7,000 sq ft lot        - $ 1,800,000Architect Fees                                                            - $     30,000Other Soft Fees (like Permits)                                     - $     45,000Construction (3,000 Sq Ft)                                           - $   700,000Finance Costs(Borrowing around $1.4 m for 2 years      - $   110,000as primary residence mortgage)Selling Costs (5% of $3.3 mil)                                       - $   165,000------------------------------------------------------------------------------------Total Costs                                                                 - $ 2,850,000Selling Price                                                               - $ 3,300,000Profit                                                                         - $    450,000Are these realistic?

Let me know if I am missing anything.Purchase cost of an old house on a 7,000 sq ft lot - $ 1,800,000Architect Fees - $ 30,000Other Soft Fees (like Permits) - $ 45,000Construction (3,000 Sq Ft) - $ 700,000Finance Costs(Borrowing around $1.4 m for 2 years - $ 110,000as primary residence mortgage)Selling Costs (5% of $3.3 mil) - $ 165,000------------------------------------------------------------------------------------Total Costs - $ 2,850,000Selling Price - $ 3,300,000Profit - $ 450,000Are these realistic?

If you have steady income, they can tell you how much you can borrow. 

If you’re talking about a multi-family residence with five or more units, the bank will typically place more of an emphasis on the economic performance of the property, and less of an emphasis on you as a borrower. 

Good question Raynard.As a non US resident I would likely  not have the option to borrow money from local banks etc .. 

I was just requested for this earlier this week and was able to float my borrower down an additional .375% from their original locked rate.

Seems strange you cant borrow against any property that is paid off, renters or not.

If you dont borrow more than youre current balance yes you are restarting a loan but adding extra principle payment and possibly lowering the interest could make a big difference in shortening your loan.

But as others mentioned, if you debt is putting you in a position to not be able to borrow money, primarily in the form of mortgages, than pay it off regardless of rate. 

I know, sometimes we have to borrow and beg for money to make it happen, but as long as we get the result we're going for it will all work out!