What are the oldest extant buildings in China? Note that while all buildings are structures, not all structures are buildings. As a building I regard an above-ground structure that has load-bearing walls and/or columns which have been assembled from any processed building material known at the time (wood, mudbrick, concrete, stone or fired brick). This specifically excludes rock-cut architecture such as caves. Buildings typically enclose an inner space, they could be roofed, vaulted or domed, but also be open towards the sky.
There is some leeway concerning the preservation state of these buildings. They do not need to be in a perfect, original state, but they should not be mere ruins, reduced to their fundaments in the worst case, either; they should be still by and large recognizable as buildings. They do not need to have been in continued use and could have fallen into disrepair for centuries, but they should not be buried ruins which have only been recently discovered, excavated and made accessible to the public by modern archaeology. They could have been restored and even incorporate later additions, but - this is important - only to the extent that one can reasonably say that the original fabric still dominates.
Examples for buildings are houses, temples, granaries, towers, barns, shipsheds, theatres, amphitheatres, circuses, baths, triumphal arches, mills etc. Structures which are not buildings are roads, walls, dams, canals, bridges, triumphal columns, monumental sculptures etc.
There is some leeway concerning the preservation state of these buildings. They do not need to be in a perfect, original state, but they should not be mere ruins, reduced to their fundaments in the worst case, either; they should be still by and large recognizable as buildings. They do not need to have been in continued use and could have fallen into disrepair for centuries, but they should not be buried ruins which have only been recently discovered, excavated and made accessible to the public by modern archaeology. They could have been restored and even incorporate later additions, but - this is important - only to the extent that one can reasonably say that the original fabric still dominates.
Examples for buildings are houses, temples, granaries, towers, barns, shipsheds, theatres, amphitheatres, circuses, baths, triumphal arches, mills etc. Structures which are not buildings are roads, walls, dams, canals, bridges, triumphal columns, monumental sculptures etc.