Depends on where you live in the first place, if you live in Iran, you’re good to go.
But assuming you don’t, there are a few things worth noting. The game is owned by Activision, and so is all it’s content and design. Design it self is not copyrightable in most countries with some common sense, so rebuilding the design of someone else is no problem. This demonstrates with the original Team Fortress for quake, and Splash Damage making Q3F for quake 3.
Rebuilding a design, would be no problem.
Copying vectors and coordinates (after all, that’s what a .map is) is a borderline case. In Dutch court, Splash Damage/Activision could not claim that it’s part of a creative work, which is protected by IP laws. Mathematics are in The Netherlands not copyrightable, (in America, they are) and as such it would be all right to copy coordinates.
In the USA, the law is far more eager to protect companies. Your case would likely be a violation of some IP law in the USA. Also, the EULA laws in the USA are far more stiff. Although Activision could claim that you violated the EULA, it would only mean that you are no longer allowed to use the program under those terms. In Europe, consumer rights protect the user to use the (legally purchased) product, even if it violates EULA. In the States, you are liable for compensations and prosecution of you violate a EULA.
I can’t give you a green flag for your plan. Based on where you live, it might be more serious. In India or China, you should just do it. In Iran, it’s your right*. In the USA, you are a vile criminal and will be shot to death.
From an other point of view. Copying a part of a building, and then texturing and editing it does not seem to be a very lucrative lawsuit-target. You might just do it, and assume that they never complain.
*Iran, although considered to be an evil dictatorship, also has the most liberal IP rights in the world. Trademarks exist, but you can not claim ownership on an idea, story, chemical formula or piece of music that is not made in that country. At least one redeeming feature of Iran.