The house has been added to(=new rooms,etc.have been built on to it) from time to time.本句括号中的解释语中new rooms,etc.have been built on意指“新房子等已被扩建”不就是完整的意思了吗?为什么后面还要加用to it,

Question

The house has been added to(=new rooms,etc.have been built on to it) from time to time.
本句括号中的解释语中new rooms,etc.have been built on意指“新房子等已被扩建”不就是完整的意思了吗?为什么后面还要加用to it,那么这里的to
这里的it若是指代the house的话，我觉得it前用on更合适，这里的to it为什么不能用on it?

Answer 1

这里的it指代前面的the house,而括号里的new rooms 是在the house的基础上增加的,括号里的意思是“在房子上已经加盖的新房子”.