Here is Louisville, Kentucky there are specific regulations regarding exterior railing. According to the Louisville Metro Government site, the Metro has adopted 2007 Kentucky Building Code and the 2007 Kentucky Residential Code. With respect to exterior railing, they state:
Handrails and guards. Every handrail and guard shall be firmly fastened and capable of supporting normally imposed loads and shall be maintained in good condition. Any alteration, modification, addition or replacement of a handrail or guard shall be in conformity with the applicable state building code requirements. Every exterior flight of stairs having more than four risers, and every open portion of a stair, landing or balcony, which is more than 30 inches (762 mm) above the floor or grade below shall have guards. Handrails shall not be less than 30 inches (762 mm) and no more than 42 inches (1067 mm) high, measured vertically above the nosing of the tread or above the finished floor of the landing, walking surfaces or grade. Guards shall not be less than 30 inches (762 mm) high above the floor of the landing, balcony or grade.
When you work with the team at Iron Crafters, all of our installations meet local building codes. If you’re not in the Louisville Metro Area, you can look up your own building codes through this reference site provided by Reed Construction Data.