cost-effect strategies for building a new unit

[Noam Birnbaum]

Hi folks,

I own an existing property in the Bay Area that has a large backyard -- large enough to build an additional rental unit. I've inquired briefly of a couple local contractors and have received ballpark construction estimates of between $300,000 - $400,000 for a 1 to 2 bedroom dwelling built from scratch. I imagine it would take 10 to 15 years to recoup this investment, which doesn't seem worth it to me.

I'm wondering what other options are feasible, such as purchasing existing construction plans, building a pre-fab, or anything else I'm not thinking of, to decrease the cost and time-to-break-even.

Thanks!