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

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 a property sale.

Zoning
Regulations controlling the use of land within a jurisdiction.

Zoning ordinance
The set of laws and regulations controlling the use of land and construction of improvements in a given area or zone

Zoning variance
A one-time modification of existing zoning laws.