IMO your safety from an investor standpoint comes with building a large portfolio.If you can keep it "under the same roof" even better.Less people to speak with and less drama with logistics and correspondence.The bigger the portfolio, the safer and the better ROI will be long term.Our most unsatisfied investors are the one's that own 1-2 properties and get pissed off with me and my company if they go vacant.Unfortunately, turnkey providers aren't magicians or God and can't wave a magic wand and turn 2 properties into 10 over night lolFolks that own 7-8 or 10+ properties with us aren't bothered if 1 or 2 are vacant, as the others are still performing and cover any losses on those that aren't.Thanks and much success

Then I work out an estimated rest of life (the building inspector did this as part of his report) and then I put in an estimated replacement cost. 

More business and jobs coming our way!

Not just residential, so it would expand the possibility of ADU construction to alot of building owners.

There are many low cost areas of the US that are impractical to invest in because of the distance with the travel and hassle building a team. 

Wether your looking for home in Granite Bay (Placer County) in the unincorporated town of Elverta (Sacramento County) or the unincorporated town of Pleasant Grove (Sutter County) all commissions are still negotiable....

This strategy acts as a low barrier to entry to allow someone with little capital to enter the investing world, to build equity, and repeat the process to continue to build their portfolio/wealth.I would be happy to go into more detail should you ever want.

There's a lot of large apartment building going on but I'm concerned that there may be too much building given the number of jobs in the area.  

Equity Building:As you pay down your mortgage using rental income, you're simultaneously building equity in the property.

I live near Whidbey Island (I'm just over the bridge in Skagit County).