General cost for SQFT addition in San Jose

[Keong Kam]

Hello Bay area folks!

I am looking at a property that I can potentially add another 1000 SQFT (from 2/1 to 3/2 or 4/2), and wanted to get a general rough estimate on the cost I should expect. Based on quick google search I am seeing ~$150/SQFT. Is that reasonable? If anyone have experience doing similar in bay area recently, please let me know!

Also, I am looking to do a garage conversion (2car garage to an ADU) down the line. If anyone has information/learnings from experience, I would really appreciate it.

Thanks!