Is just the fact that no garage could be a no go for some buyers enough to build it even if it only raises the value by the actual cost?

Sometimes I have even directed troubled tenants towards assistance programs (such as single moms because there are a lot of programs for them specifically in my area especially).

They don't even know what to do with it.

Look into meetups through BiggerPockets, local REIA (Real Estate Investors Association) groups, or even events in nearby Seattle.

Slate roof or even Spanish tile.

Even the funding alone is easier since you now have a cash flowing property that can help you fund your seed money faster. 

But the competition is high so cash flow or even break even can be an unphill battle unless you're willing to put money into the property.

Even if it's a new build, with 4 units, you're going to have lots of repairs.

Also, focus on 2 years of job/income stability.Class D Properties:Cashflow vs Appreciation: Typically, all cashflow with little, maybe even negative, relative rent & value appreciationVacancy Est: 20%+ should be used to cover nonpayment, evictions & damages.Tenant Pool: majority will have FICO scores under 560 (almost 30% probability of default), little to no good tradelines, lots of collections & chargeoffs, recent evictions.

@Chris Seveney even better results can be obtained with a Solo401k , if eligible.