How to build a Wind Phone
A dead handset and a place to stand with it.
The idea does not require carpentry, and most of the Wind Phones built since Ōtsuchi have been made by people with no special skill for this, just a dead phone and somewhere to put it. Here is what the actual list of requirements looks like, stripped of anything decorative.
The phone itself
You need a handset that is not connected to any line. A rotary phone is the classic choice, mostly because the first one was one, but any disconnected phone works: an old corded phone from a thrift shop, a payphone handset, even a phone with the cord cut and the base left empty. What matters is that picking it up and holding it to your ear produces a familiar, specific posture. Your body already knows what to do with a phone against your ear. That is the entire mechanical function it needs to perform.
If you are building outdoors, weatherproof what you can. A booth, a shelf under an overhang, or even a simple weatherproof box that opens to reveal the phone will keep the mechanism usable through rain and damp. Electronics are not required, so there is nothing to short out. The main enemy is rust on the metal parts and rot on any wood housing, both slow problems, both manageable with basic exterior paint or varnish and a roof of some kind, however small.
Where to put it
Privacy matters more than scenery. Most people will not speak out loud, even to no one, if they think someone might hear them or watch them do it. A garden corner works. So does a spot along a quiet trail, a hospice courtyard, a corner of a school memorial garden. What you are looking for is a place where a person can stand for a few minutes without an audience.
A view helps but is not required. The original sits on a hill above the sea, which gives it a kind of openness that suits the act of letting words go somewhere. A gap in the trees, a bench facing a field, a spot where the sky is visible rather than boxed in by walls, all do a version of the same job. If your only option is a corner with no view at all, that is still enough. The privacy matters more than the vista.
The notebook
Many Wind Phones keep a notebook and pen nearby, sometimes in a small waterproof box, so people can write something if speaking is not what they need that day, or write something after they have spoken. There is no required content and no one reads it as a duty. It just gives people a second way in, for the days when a phone call feels like too much and a few written lines feel possible instead.
Whether to open it to others
This is the real decision, more than any material one. The Ōtsuchi booth was built for one person and only became public later, and not every Wind Phone needs to follow that path. A private one in your own garden is a complete, finished thing on its own. If you do open it, even informally, tell people what it is for in a line or two nearby, so a stranger who finds it understands what they are looking at without needing it explained.
Say what you need to say. The line is connected to nothing: no one hears you, nothing is recorded, nothing is stored.