SKYDB
Data backbone

Other information
besides just buildings.

SKYDB is built from regions, companies, photos and the dictionary that ties them together. Pick a thread to pull.

Explore database →

317,027 tall buildings

definition strict definition

horizontal addition completed

A new extension to the side of an existing structure is finished and ready for use.

A horizontal addition to a built object is completed when a significant extension at the side of the existing object, abutting it while resting on new foundations, is physically finished and ready for use. If the addition is built on top of the existing object, it should be classified as a vertical addition.

The completed extension must abut the existing object and rest on new foundations beside it. A separate building nearby is not this side addition.

Horizontal addition begins construction records the start of the extension. Its completion concerns readiness of that new space for use and can occur long after the original object was completed.

Related definitions

Definition
strict definition
Key
timeline.horizontal-addition-completed
Last updated
Sep 10, 2026