Thinking of adding an accessory dwelling unit (ADU)

[Chris Sawtelle]

I own a SFH about 10 blocks east from SJSU in downtown san jose. The new google facilities are going to about the same distance the opposite direction. The property has long term tenants and is zoned for two family residential. I am thinking of adding an ADU due to the relaxation of regulations and I have been weighing the options between a manufactured or modular (not mobile) home and doing new construction. My in-laws just completed a 640 sq ft stick built ADU that cost nearly $200,000 with them doing a lot of work on it. It seems that if I was hands off the cost could be 250k+, and I would expect to only be able to get 1000-1400 in rent. Does anyone have any experience for doing this?