The address is spelled out in 3-inch brass script letters on the front door, the door stands 60 feet back from the street, and the brass sits against a brass kick plate. The builder asks whether that satisfies the address requirement. What does the code require?
- ANumbers not less than 3 inches high placed anywhere on the dwelling, with visibility from the street left to local ordinance
Three inches is under the required size and visibility is not a matter left open. The provision is aimed at a fire crew finding the house at night, so where the numbers can be seen from is central to it.
- BNumbers not less than 6 inches high and internally illuminated, so the address stays legible at night from a moving vehicle
Six inches and illumination exceed what the code asks. Requiring more than the provision asks is still incorrect at an inspection, and it invites an argument the department will lose.
- Numbers at least 4 inches high with a stroke of 1/2 inch, contrasting with their background and visible from the street
- DNumbers placed on the mailbox rather than on the dwelling, so that the address sits at the street however far back the house is
A mailbox is not the building, and mailboxes are moved, knocked down and grouped at the roadside in clusters. Where the dwelling cannot be identified from the street, additional identification at the driveway is the usual remedy, in addition to the numbers on the building.
Why C is correct
Three requirements have to be satisfied together: character size of at least 4 inches with a 1/2-inch stroke, contrast with the background, and plain visibility from the street fronting the property. This address fails all three, which is why the size of the numbers alone does not settle it.
What this question is testing
Whether the candidate can state the three parts of the requirement, size and stroke, contrast, and visibility from the fronting street, rather than remembering only the height.
On the job
Address identification is the last item on many final inspection checklists and one of the more consequential ones. Fire and emergency medical crews lose real minutes on rural and deep-set lots. The two failures an inspector sees constantly are decorative numbers chosen for looks with no contrast, and correct numbers mounted where a porch column or a hedge blocks the sight line from the road.
Memory technique
If the truck cannot read it from the street, it does not count.
Exam tip
Four inches, half-inch stroke, contrasting, and visible from the road.
Where to look it up
IRC Chapter 3, building planning, premises identification.