It's easy to search on Redfin/Zillow with the keyword "ADU" now.I found some recent transactions data (almost all from second quarter of 2021) in the bay area that might be of interest to you: https://www.redfin.com/CA/Camp...https://www.redfin.com/CA/San-...https://www.redfin.com/CA/Sant...https://www.redfin.com/CA/Sunn...https://www.redfin.com/CA/Sant...https://www.redfin.com/CA/San-...You can see that in all of these cases (whether with detached or attached ADUs), ADU added more value than the estimated construction cost, which shows that building an ADU can be a proven strategy for bay area home owners to not only improve cash flow, but also immediately add equity value.

If you are willing to pay a decent amount for good data and lists that aren't as easily affordable as what someone who can afford Propstream could get, then there is Audantic, which the folks in my master mind has good data/lists.

Plan 2This plan keeps the same hall-way but creates an entry way through an existing bedroom which we use purely as an office room.

House hack: The barrier to entry is low when you use the FHA financing .

I'd check with other data resources to confirm your assumptions. 

Might take 200k all in especially if you're leaving some cash in a contingency fund (recommended). check out airdna and see what occupancy and lease rates look like in your target cities. this should help put into perspective what kind of cash flow to expect then cross reference that data with zillow listings to see what type of purchase prices you should expect. 

They have absolutely no realization that the reason the appraisal report was turned in so late is because the alternative, using the $475k data point on a $600k transaction, would have sunk the deal entirely! 

There should be no need to speculate- The market around you should provide data to determine if adding square footage is worth it.

I am currently house hacking in Westminster CO and have a house where the basement has a 1,000 sq ft basement "mother-in-law" suite that has a lockable, entry door in the basement utility room. 

The data ranges from appreciation of median home price to job growth.With an overall rank of No. 2 on WalletHub’s Best Places to Buy a House list, Austin also lands in the No. 1 spot in terms of large cities with hot real estate markets.https://austin.culturemap.com/...