An improvement is anything that was added to the property and that adds value: from a home to a fence. They are declared by whoever publishes.
Improvement is not the same as construction
The distinction matters when searching. A mill and a perimeter fence are improvements that add value but are not buildings: a property with a mill and fence is still an property without building, and that is exactly what many people are looking for.
| Improvement | Is it construction? |
|---|---|
| Housing or farmstead | Yeah |
| Shed or open shed | Yeah |
| Corrals, cattle race or head gate | Yeah |
| Silos | Yeah |
| Mill, drilling or watering point | No |
| Perimeter wiring | No |
| Electrical energy | No |
| Irrigation | No |
That is why the filter has three states and not two: with constructions, without constructions—it can have a mill or wire—and pure property, which is the one that does not declare any improvement.