If we consider that we can make some regions fully grown with trees and green and on the ground to have armor stands with peace of metal, spoon or some small stuff and only that to says there was a house. But with stone base overgrown with vegetation will look definitely betterConsidering that Lond Daer started out as a harbour city for shipping logs to Numenor some of the oldest buildings would probably have been wooden houses as that would be the by far most common building material. Obviously nothing of these wooden houses would have survived into the third age but it's an interesting historical point nonetheless I think.