Needless to say I did not buy one as our temperature regularly gets down to -20.

Requirements, 10 x 20 bunker, "solid" door, water and humidity dry, temperature moderate or controlled.   

IG: @MattPriestJr I have properties that I rent by the room in King/Pierce/Snohomish Counties.Many pro tips.For heating, I use Nest Thermostat and "lock" the temperature on 68 degrees. 

Do you know what temperature the tenants have the heat at?

That can largely be avoided by planning ahead to keep it separate as possible,  and submeter or mitigate in other ways when not possible;  like apparently these days you can get programmable thermostats with a 'administrator' mode that will allow you to set a maximum temperature in case you end up sharing with a resident who likes to keep the house at 80 degrees with electric baseboard heat.   

SF Bay Area, especially in terms of SFH construction quality, market temperature, tenant quality etc.

And I was pretty happy moving into a house vs. an apartment where the heat temperature was not controlled by me!

In the summer, the temperature rarely gets into the high nineties and almost never goes above 100 degrees.

When I do go outside, it is beautiful and like many others have noted we have so many different temperatures and different activities.

It's very expensive, has horrible traffic on restrictive roads due to the geography, but is very beautiful, not much snow, milder temperature swings, great hiking and outdoor activities such as 4x4 or hot air balloon tours - very touristy.