Answer:
What is often on the ground getting stepped on by others, but you donโt have to wash it because it never get dirty, in fact you couldnโt wash it even if you tried?
What bank has no money?
What freezes after it is heated up?
How many bricks does it take to complete a building made of brick?
Take one royal word in the plural and make it singular by adding one letter
I am used for light yet I am solid. Without me you would feel enclosed. I hate being touched especially with a lot of force. I like to be in buildings.