Consider all the factors and pick the best one.

Vacancy is the final factor...and the hardest to determine. 

Here’s my question:•I have designed a 6 unit, 1 bedroom, single storey development.• I am considering going double storey however I fear that I will lose the comfort and “family friendly” environment single storey allows.• will the intangible value of a single storey comfortable environment surpass the rent of 3-4 more units?

The guy I learned from, when he started out, his designated broker/owner wouldn't let him sell anything he didn't buy himself.

Urban sprawl is a major factor to consider.

What's important to note is that while they may not report to the agencies, therefore not be factored into your DTI, you need to monitor your debt levels to ensure you're not taking on debt obligations that you're unable to afford.

When you factor everything else in, it could be a deal that's not as good as you had originally thought.  

But down payment is only one of the factors, I'm sure if you had a net worth of $50MM you could get away with 10% down. 

Agreement will be affected by number of other factors as well so its better to get a legal consultation. 

Columbus, again in my opinion, is sheltered from many factors that will effect other areas.