ADU in Bay Area California - contractor and loan info

[Jitendra Mandalia]

Hi BiggerPockets,

I am planning to build a detached ADU. I am located in Dublin CA. I am talking to local contractors and architects to understand the cost, timeline and benefits. I am posting it here to get feedback from the experienced people. There are multiple options i.e. prefab or build from scratch etc. As of now I am looking to build one with the help of a contractor, and looking for some local contractors who can help build it end to end, including architecting, permit approval and construction.

There have been lot of changes in the county rules and the approval process has become much easier compared to what was there in the past 2-3 years back. With that the ROI has improved a lot.

After looking into various financing options, I am planning to use my pre-approved HELOC and cash to finance this.

Is there any specific thing which I should be aware or take care for this project in Bay area? 

Thanks in advance for any suggestion or tips.

Best,
Jitendra