Bank of America will indeed value tenant income, however, you'll need to provide proof of multiple years of steady tenant income before they'll value it above zero.
That's unusual: whenever we got a new mortgage or refinanced (US Bank, Wells Fargo, Chase, ...), our rental income and the rental cost was included in the calculation.
To clarify - tenant income from renting out one of the rooms of the place I'm trying to buy (not existing tenant income).
Basically the peninsula is unaffordable to own alone, but if I could get a two bedroom and rent out a room I could do it (alternative is having to buy in SF a one bedroom for 780-875k). Banks don't let you do this though and without this I'm priced out of two bedroom units.
I suspect you could create some new mortgage instrument that allows groups of friends to buy a house together since now we typically just do this via renting and splitting the cost for individual rooms (though I hesitate to suggest this since it would ultimately drive up prices even higher). It's also hard to find people willing to risk this, but I think a standard contract structure could go a long way to reducing the social risk.
though I hesitate to suggest this since it would ultimately drive up prices even higher
I went to one open house in SF and the top floor was a nicely updated if small house. The basement/garage? The owner had put up walls to create 6 rooms and 2 bathrooms. The rooms were maybe 10'x10'? Apparently they rented them out to help with the mortgage. You could probably get $500-700/month for each or $3000-3600 for all six?
And that's one reason why parking is an absolute mess in SF even if you get away from the city center. A lot of houses have one or more in-laws (many illegal). And no place to park the car in the garage!
You can absolutely get a joint mortgage with a friend: I did. The real challenge is finding someone you want to go in on a long-term coliving arrangement with, agree with on how to handle home maintenance and the like, and trust not to try to screw you over.
They did value whatever the max was you could borrow against your 401k.