Advice on Converting a two level home into two units in Brentwood

[Gadde Saikumar]

Hi, I tried to buy a huge single level single family home which has a floor plan where it can be converted into two units very easily. A small wall and a new kitchen. But I couldn't get that deal. Now I am looking at equally bigger house but on two levels and 100k less. The only addition I need to do is add a new kitchen and reroute steps. 2 bed 1 bath on the ground floor and 3 bed 2 bath on the top floor. Apart from the permissions, Do I need to consider something else ? I am looking in SF bay area. 

When I call the county, they say that I need to send a proposal by architect in order judge whether it can be done. But for that, I need to purchase the property. I am a bit confused on what to do. Really appreciate your feedback, help.