Generally , these homes should be close in location, layout, size, age, and condition.

Also something I didn't mention is there is a generous sized fenced in back yard with a garage.

Verify their income and employment .

Tax strategies can certainly boost returns, regardless of what real estate strategy you employ, but I think asking "do the higher short-term returns make up for the tax consequences" is somewhat backwards. 

When building spec homes, how do you determine the size of homes to build?

Apartments can go up to 80% ltv depending on the loan amount size and if the property and buyer are strong. 

There is no one size fits all, and you'll likely leave hundreds if not thousands of dollars on the table if you do not consult an attorney.

Unlike passive rental income, the income from an active trade or business is subject to self employment tax (a nasty 15% tax commonly referred to a “social security and medicare” by working folks).

Tranportation imporvements, Vacancy rates, unemployment, average household income, growth rate of population, available rental stock, infrastructure improvements, large employers moving in.

I live just west of Portland, and I'm looking to get into REI a little more to supplement my retirement as I'm self-employed (General Contractor) and don't have much of a traditional 401k, etc.I started out buying a duplex as my first house back in 2005, which I lived in one side for 7 years and rented out the other.