With upgrades we have planned to the units, that situation will only marginally improve over the next several years.Planned upgrades:New windows - $2500 x 17 = $42,500New HVAC & central air - $3000 x 9 = $27,000Interior upgrades to remaining 9 units - $3000 x 9 = $27,000TOTAL - $96,000This sounds daunting, but over the remaining 4 years of our 5 year plan equates to $24,000/year, or $2,000/mo., which is quite manageable.

The major repairs I have done are replacing the well pump and pressure tank, and redoing the bathroom.  

That has been our strategy with our owner occupied houses, while we have also added rentals near Air Force bases. 

We ended up taking the room down to the studs and joists -- replaced the sub-floor and re-framed in a new back wall, and then re-framed in an area for the tub/shower, and had a plumber come in to re-arrange the plumbing/water-supply  (this was the biggest headache), and the air-ducts.  

That said you can keep the curtains over the window area even when it is open so the cats don't stare at each other. there are small pressure rods you can put in the window with light cotton curtains on them.  

It's alright to put that pressure on them too ha.

Hope this clears up the air a little more 

@Michael Greenberg, Sonoma has become so known for being a travel/tourist destination, they started limiting the option to have an air BNB due to multiple complaints from the local homeowners and residents about the amounts of traffic and other areas that had been severely impacted by all the visitors.

While these claims are true, each one is a legitimate claims -- 2 of which were for minor issues resulting in ~$300-500 claims, one involving theft and vandalism for roughly $4,000 (someone stole the central air unit and cabinets), and the other two are on his primary residence -- hail damage, etc. 

I'd throw a pressure washer at it at a minimum.