A groundscraper is a large building that has relatively few stories but which greatly extends horizontally.
Definition
Encarta defines groundscraper as "a large low or medium-rise building, typically containing offices, that spreads horizontally and occupies a large amount of land".
Examples
5 Broadgate, a groundscaper owned by Swiss bank UBS, is the largest office building in the City of London. Horizontal Skyscraper – Vanke Center in Shenzhen is as large as the Empire State Building, but is laid out horizontally and 5 stories above ground level. A park occupies the space below. The Pentagon - the world's second largest office building Apple Park Bharat Mandapam The Squaire Colossus of Prora, originally 4.5 km (2.8 mi) in length. Estonian National Museum