What is an NCZ? (Or a clear span)

One of the things we often have to explain to people when we do a pool or spa safety barrier inspection is the idea of an NCZ.  In the safety barrier standards, an NCZ goes by a few names (no climb zone, non-climbable zone, nonclimbing zone), and it’s also known as a clear span in the earlier standards. Regardless of the name, it means the same thing:  an area outside (and sometimes inside) a pool barrier that must be clear of climbable objects.

The most common NCZ is a quarter circle that starts at the outside top of the pool fence, stretches out horizontally, and then swings down to the face of the pool fence, forming a quarter circle.

The size of it (the radius of the quarter circle) varies according to your pool barrier standard. it can be 1200 mm for older barriers, or 900 mm for new ones. Sometimes (again, depending on which standard you have to comply with) it does not start at the top of the fence. In any case, it extends all the way along the length of the fence.  This is the NCZ.

The NCZ is the space that has to be kept clear of climbable objects.  We have a whole article on what climbable objects are.

The technical details vary a little from standard to standard, but in essence you don’t want anything inside the NCZ that a child could use as an aid for climbing. A couple of common examples of climbable objects are garden beds and trees.

Your inspector should make perfectly clear to you exactly what the requirements are for your particular standard.

Some things are okay in an NCZ, but the details change from standard to standard. Your pool inspector should be able to tell you exactly what’s allowed and what is not.