As a real estate broker that also has a real estate appraisal license and general contractor license, I can tell you no one can answer this question accurately without doing an on site assessment (I have also built my own 6,000 sq ft home). Here are questions that GREATLY impact the cost.
- Land (is it hillside, flat, slope)
- City / development requirements (how much can you cut into land/ How much fill dirt)
- Are city service ran to street, if so how many feet will you have to run
- Size of home (typically as size increase the cost per sq ft declines)
- Upgrades (not just interior, but quality of construction from roof, windows, air units etc)
Typically the best place to start is to meet with a quality architect. Make sure you review references and explain the the building cost is to remain reasonable. Architect have some great "ideas" that will cost you a fortune and will have to be reworked when your construction team tells you that the way that feature is designed add $30k to the project.
Best of luck!!
Kindred Real Estate