The rules for the location of zone 0 are surprisingly easy to understand. As always in anything involved in construction, there are a few boundary cases that need comments.
The general case
- Zone 0 starts at the bottom of the walls of the structure, and extends 5 ft out.
- If there are combustible attached outside stairs or landings, zone 0 wraps around the outside edge of the stairs.
- If there are combustible attached decks, zone 0 wraps around the outside edge of the decks.
Pre-existing outbuildings built partly or wholly inside zone 0
- Hot tubs are explicitly allowed within zone 0, which will then wrap around them
- Other outbuildings are allowed IF they were built to code at the time they were built (even if they did not get permitted). Zone 0 will wrap around them.
- such outbuildings could be for instance gazebos, landings, decks, stairs or other structures.
Cantilevered parts of a structure
- any cantilevered part of a structure that is unsupported except at its base, and that is more than 4 ft over the ground, has no impact on the location of zone 0
- any cantilevered part of a structure that is less than 4 ft over the ground needs to be screened on its outside edge, and the bottom of the screen is where zone 0 starts.
- any cantilevered part of a structure that is supported elsewhere than at its base is equivalent to a covered porch, and zone 0 starts on the edges of its supports, or, if unusual geometry, on the edges of the cantilevered part.
Questions
Q. My home has eaves. Where does zone 0 start around the structure?
A. it starts at the bottom of the walls (not by the edge of the eaves).
Q. My home has a cantilevered second floor. Where does zone 0 start around the structure?
A. It starts at the bottom of the walls. It extends 5 ft out. But—if the cantilever extends beyond 5ft, it would be dangerous to plant anything beyond 5 ft but under the cantilevered section: common sense, but not requirement.
Q. My home has a cantilevered porch, supported by pillars. Where does zone 0 start?
A. It starts on the line defined by the outside bases of the pillars: they are also part of the structure.
Q.I have a hot tub that impinges upon my zone 0. Can I keep it?
A. Yes. Zone 0 wraps around it.
Q. I have a gazebo that impinges upon my zone 0. Can I keep it?
If it was built to code at the time when it was built, yes. Zone 0 wraps around it. If it was not built to code at the time, no.
Q. I have a detached deck with stairs that impinges upon my zone 0. Can I keep it?
If it was built to code at the time when it was built, yes. Zone 0 wraps around it. If it was not built to code at the time, no.
Some Nextdoor myths and misrepresentations (there are many more)
IBHS says that zone 0 starts at the eaves -->FALSE
You cannot keep your hot tub if it is less than 5 ft from your house -->FALSE
You cannot keep your gazebo if it is less than 5 ft from your house -->FALSE if it was built to code
You must cut all your trees in zone 0 -->FALSE if your trees can be limbed 10 ft above your roof line
You must take out all your combustible fences within zone 0 -->FALSE only your attached fences
You can keep your combustible gates within zone 0 -->FALSE
NextDoor is dense with misrepresentations and untruths about EMBER. Get your information from the source: attend an EMBER workshop and ask your questions there.