We built or single family residence in 2008-2009 after the fire. Existing lot had all communications available.
About 3500 sq. ft. Permit fees waived. Did cost us about $650K – close to $185 per sq. ft. Very high end – ICF (concrete) house, metal roof, metal clad wood windows, etc.
And we did not have a general contractor plus we did some things ourselves – flooring, tiling.
And it was ten years ago.
If you chose low end materials you can end up with less than $300 per sq. ft.
