In our game (Holy Knight) I was the architect. I looked at the blueprints and pictures of the Florence Cathedral and tried my best to make an accurate representation for our game. Overall, I think it came out quite well. I do believe that the scale is actually larger than I made it; that is, it is probably bigger in real life than it was in our game. At first I thought the area in-game seemed so big, but after going back and looking at the size of people compared to the architecture, I think the place is bigger. It's hard to get a good scale that you can really feel when a building is so massive. I can look at pictures and measure the average human height and such -- but nothing compares to being inside a building to really nail the scale well (if you don't have measurements and blueprints, which we really didn't.)
Following are pictures of the work I did, in no particular order.
Bret made these assets (except the books which I made) and I placed them.
More pictures to follow