Subdividing Property in San Diego County

[Curtis Chism]

I'm working with a client who is interested in purchasing a house as a rental in San Diego County (not the city) that is on nearly 2 acres of land. He'd like to subdivide it to build a second house and rent that out as well. I'm not sure how to find out if the property is able to be subdivided. Can someone point me in the right direction? Thanks so much.