zero-lot line
The positioning of a house near or on top of the lot boundary, resulting in little or no space between houses. 

zero-net
When the seller receives little or no net proceeds from the property sale.

 Z-flashing
A special type of metal flashing that protects horizontal joints between siding panels that don't overlap. It has a Z-shaped profile and is designed to tuck up under the upper panel and overlap the lower one. 

zoning
Regulations that control the use of land within a jurisdiction. 

Zoning Ordinances (or Zoning Regulations)
Local law establishing building codes and usage regulations for properties in a specified area.

zoning variance
A one-time modification of existing zoning law.