You need to obtain a building permit for many reasons. A building permit ensures that your structure is in compliance with the building code and meets the minimum building standard. Building codes are rules that are intended to make buildings safe for the occupants that occupy the structure.
Insurance companies value building codes, when updated codes are in place this usually means the buildings are more safe, stronger, and more likely to withstand severe weather events lessening the amount of loss to property. Building codes can safeguard public health by regulating wastewater and other potential health hazards that may infiltrate into your neighborhood.