Oh, and I forgot to say one thing:

Others in the past have created Quake/Doom/Unreal levels based on their homes or offices. This is one of the very first things people did as soon as Doom editing was available. All of these maps have invariably sucked. They were boring compared to properly-designed game maps. Once the novelty of seeing your office bathroom in Quake has worn off, there is nothing left to make it interesting.

Designing a good game map is an art which requires an intimate understanding of what makes a game fun. The actual layout of the map, its very architecture, is what determines its fun factor. The architect who designed your house or office building intended to make it logical and functional, not fun. He designed it for normal people to use for normal every day living and working. He did not design it for someone to run around at 60 miles per hour with a rocket launcher. So it would follow that any maps based on your house or office would not be fun to play in, at least not as a Quake game.

And there is also the Single-vs-Multi issue. Early on, it was discovered that a map that's fun in single-player mode isn't necessarily fun in Deathmatch. Most games now have completely separate single-player and deathmatch maps for this reason. The newest games have even further subdivided this into individual maps for different types of deathmatch and team games. With that kind of speciality, how can you expect to make a fun game out of your office floor plan?