Final answer:
The Saint-Denis Basilica is the first building to represent Gothic architecture, marking the start of the style with its innovative structural designs and the use of light.
Step-by-step explanation:
The first building to represent Gothic architecture is the Saint-Denis Basilica, which is recognized as the birthplace of the Gothic style. This architectural style emerged in the 12th century in Paris with Abbot Suger being a pivotal figure in its development. The Saint-Denis Basilica is acknowledged for its high vaulted ceilings, extensive use of stained glass, and structural innovations such as pointed arches and flying buttresses that allowed for taller buildings and more light, symbolizing the grandeur of Heaven. While other cathedrals like the Notre-Dame Cathedral and Chartres Cathedral also exhibit the Gothic style, they were constructed later and demonstrate the evolution of the style rather than its inception.