Is it not good to build a house on the land that used to be a temple?

Yes, as the saying goes, the temple is the home of Buddha or Bodhisattva, and he will not be happy if you occupy his land.

Others say that purple gas comes from the east, and it is not good for you to build a house next to the temple, which will also affect the gods and buddhas.

However, everything is old-fashioned Modern geomantic omen is said from the perspective of easy living and health preservation. No temple. Never heard of it.