1)then why the sentence << Этот дом новый >> is correct? I don't completely get it...
2) what do you guys think about this rule I found?
"Use the indeclinable это to translate English phrases starting with 'This is', 'These are'.
Use the demonstrative pronoun этот (эта, это, эти) to translate such word combinations as 'this house ' - этот дом, 'this shirt' - эта рубашка, 'this dress' - это платье, 'these students' - эти студенты."