What is the difference between मकान and घर?
मकान is used, often impersonally, to refer to the building that constitutes a house. On the other hand, while घर can also be used to mean 'house', it is more often used to mean 'home'.
Both are house
When do we use इस as opposed to यह?
I would also like to know the answer to this question.
I have since learned that इस is the oblique form of यह. Which makes sense with the possessive pronouns like यह + के = इसके etc.
Why it's wrong to use as "This is not new house"
'This is not a new house' would be यह (एक) नया मकान नहीं है. The subject of this sentence is 'This'/'यह'.
On the other hand, the subject of 'यह मकान नया नहीं है'/'This house is not new' is 'This house'/'यह मकान'.
Why not "building"?