Groundscraper

A groundscraper is a large building that has relatively few stories but which greatly extends horizontally.

Encarta defines groundscraper as "a large low or medium-rise building, typically containing offices, that spreads horizontally and occupies a large amount of land".

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The Squaire , Frankfurt Airport, Germany. With a floor area of 140,000 square metres (1,500,000 sq ft) it has more office space than any of the skyscrapers in Frankfurt .
Estonian National Museum main building