It will be more expensive to develop a hillside property – our granny flat was hillside development.
They buyer will probably need separate permits for:
*civil engineering (drainage and grading)
* structural (retaining walls).
This is in addition to the regular building permit.
Our project had 3 separate permits, 2 different city inspector departments (building services and city engineering), 3 different engineers (structural for the building, structural for the retaining walls, civil for the grading plan.).
And if there are deep footings for the retaining walls – better make sure your grader is OSHA certified. That limits your pool of grading contractors.
Add about $100k to the project before you even consider the building portion of the project.