Rebuilding Maps from CS and using in my game

Hi, i make a game similar to counter strike. It would be no 1 to 1 clone with just better graphics. I change some things, for example that bullets have ballistic.
I really like some maps from the game, above all the old maps that are not really playable in cs go like italy, assault and aztec. So I want to rebuild and use them in my game. But I really don’t know if this is allowed or if it is possible for valve to take actions against it.
Maybe one of you knows better than that?