Is index fund better than mutual fund?

Hi,

I came to know that index funds are invested on index based companies & gives returns based on the tolerances etc…..
My question
-which one is gud , index fund or mutual fund.
-Is Index fund is good for short term(1-2years) or long
term investment(3-5 years).
-may I know what would be the avargae annual return
for an index fund approximately.

Can any one of you suggest me which one is the best
index fund & how to get it?

Thanks

Is it possible to build a flat in top floor of a building which will not be excessively hot during summer?

A flat under construction is available for sale in a good locality. I am interested but worried because it is on the top floor and is likely to be extremely hot during summer. Can anybody please suggest if there is any way to build the flat in the topmost floor so that it won’t be excessively hot during summer? I mean the construction itself should be so that the rooms would not be too hot. Installation of air conditioners is a different issue I am not considering at the moment. Thanks.