*I have not successfully completed a land development deal, but am also interested in land development.
I've heard the trick with land development is getting the right Land at the right price - 10% being a good target to shoot for.
I've also met with a developer who said he looks to "double" on every deal - meaning he is spending 200k for land/permits/materials/labor and targets a 400K sales price
In my area, 4 units+ is the trigger point for all sorts of additional complicated planning reviews and requirements, curbs/gutters, traffic studies, environmental reviews, etc... so a triplex/duplex only requires the same review as a Single Family home.
So, I'm just building an excel spreadsheet with best/worst case budget #'s for each step in the process, get an approved set of plans and then I'm going to shop it to 3-4 builders I already like in my area.
I might just have them do foundation/framing/mechanicals/etc... and I'll finish it off with drywall, paint, tile, cabinets, etc...