Building a house on a steep slope - California

[Mark Vesu]

Hello all, I am interested in a piece of land that is on a steep slope.  I like the view and wanted build a small 500 sq "loft"  to use it as a weekend getaway / airbnb. I think California coastal commission will also be involved in the approval process, in addition to the city.

Before going forward, i would like to get a rough estimate as to how much it will cost to build a loft, septic tank, and a well.  I would like to get this done for a minimal cost to see whether it is worthwhile buying the place.  Appreciate any ideas and experience.

Thank you