When is a guardrail required?

A guardrail is required when:

  • Porches, balconies, or raised floor surfaces, open sides of stairs located more than 30 inches above the floor or grade.
  • In one and two-family dwelling, guardrails shall not be less than 36 inches in height for porches, balconies, or raised floor surfaces, and open sides of stairs 34 inches minimum measured vertically from the nosing of the treads. If guardrails are also going to be used as handrails, see handrail section.
  • In most other uses, guardrails should be at least 42 inches in height measured vertically above the leading edge of the tread or adjacent walking surface.
  • Open guards shall have balusters or other construction such that a sphere with a diameter of 4 inches cannot pass through any opening.


The triangular openings formed by the riser, tread at the bottom rail at the open side of a stairway shall be of a maximum size such that a sphere 6 inches in diameter cannot pass through the opening.

Show All Answers

1. How long is a permit valid?
2. How many person(s) are allowed per habitable room?
3. Can my roof support the installation of a solar panel?
4. What are the stair riser and tread requirements?
5. When is a guardrail required?
6. When are graspable handrails required?
7. How much frost protection should I have?
8. What R-Values should I insulate to?
9. What are ground snow load and wind speed requirements?
10. What size does a bedroom egress window have to be?