Thank you for all of you =) I undestand now ^^

子 is a usual suffix for some nouns. there're a lot of words have the same prononciation in chinese language, for example,房 and 防. it's difficult to distinguish them. so we usually add "子" to nouns in order to distinguish it from other words that have the same prononciation. so, 房子=房, 车子=车, 竹子=竹....and so on

子 is just a intensive particle word and this can be intensive when people saying something.

Thank you, i got it =)

房子is a word,you can't disconnect this word.The meaning of 房子is house.