For what reason might a building require modified design for earthquake resistance?

The modification of a building's design for earthquake resistance is often required due to its shape impacting resistance. Buildings that have irregular shapes or configurations can experience uneven forces during an earthquake, making them more susceptible to damage. A design that considers the building's geometry can significantly influence how the structure distributes seismic loads. For instance, tall, slender buildings or those with large overhangs may need enhancements to their structural system to ensure adequate stability and performance during seismic events.

The other options do not directly address the fundamental necessity of earthquake resistance. Increasing overall building height may pose additional challenges in terms of stability but does not inherently call for modifications specific to seismic loads. Enhancing aesthetic appearance typically involves design choices that prioritize visual impact rather than structural integrity. Similarly, reducing material costs is a goal that must be carefully balanced with the need for safety; cost-cutting measures could compromise a building's ability to withstand earthquakes. Hence, the building's shape and configuration are of paramount concern in ensuring it can effectively resist seismic forces.