Not an expert here but I know of no civilized area that does not require building permits unless you want to build a barn of less than 200 square feet.
"A building permit is your assurance that your building or structure has been reviewed and inspected for compliance with minimum building codes, zoning ordinance and environmental requirements. By obtaining a building permit, you are helping to ensure that all structures and buildings are safe, sound and worthy of the often considerable investment they represent."
Recently a family member (a self described hand-man) did his best to improve some electrical work on our behalf in the Laker Tahoe area.
He proceeded with good intention to install a new heater and other minor improvements without any building permit .... all to be done with my permission due to the need to get the job done immediately before the winter season started.
Winter came with 12 feet of snow and a malfunctioning heater (improper installation) so the cabin was closed down this year for the winter until we could dig in and get it fixed properly
I have been told by numerous contractors that a proper building permit would have helped solve the problem and to always and only employ those who are knowledgeable and are fully insured.